iii^..i 


mum 


For  Reference 


NOT  TO  BE  TAKEN  FROM  THIS  ROOM 


•  "^'-  I  CALF 


LIBRARY     OF 


1885- IQ56 


PLATE   I 


nfarr  U'eUmnv,  del. 


PLATE   T. 
SPHINX-MOTHS. 

1  =  Pholus  pandorus. 

2  =  Smerinthus  geminatus. 

3  =  Ainpelophaga  versicolor. 
4=Marumba  modesta. 

5  =  Hemaris  thysbe. 
6=Thyreus  abbotti. 


American  j^aturr  Series; 

Group  I.      Classification  of  Nature 


AMERICAN    INSECTS 


VERNON   L  KELLOGG 

Professor  oj  Entomology  and  Lecturer  on  Bionomics 
in  Leliind  Stanford  Jr.   University 


WITH  MANY  ORIGINAL   ILLUSTRATIONS 
BY 

MARY   WELLMAN 


NEW  YORK 

HENRY   HOLT   AND   COMPANY 
1906 


Copyright,  1904 

BY 

HENRY    HOLT   AND   COMPANY 


ROBERT    DRUMMOND,    PRINTER,   NEW  YORK 


TO 
JOHN  HENRY  COMSTOCK 


PREFATORY   NOTE 

If  man  were  not  the  dominant  animal  in  the  world,  this  would  be  the 
Age  of  Insects.  Outnumbering  in  kinds  the  members  of  all  other  groups 
of  animals  combined,  and  showing  a  wealth  of  individuals  and  a  degree 
of  prolificness  excelled  only  by  the  fishes  among  larger  animals,  and  among 
smaller  animals  by  the  Protozoa,  the  insects  have  an  indisputable  claim  on 
the  attention  of  students  of  natural  history  by  sheer  force  of  numbers.  But 
their  claim  to  our  interest  rests  on  securer  ground.  Their  immediate  and 
important  relation  to  man  as  enemies  of  his  crops,  and,  as  we  have  come  to 
know  only  to-day,  as  it  were,  as  a  grim  menace  to  his  own  health  and  life — 
this  capacity  of  insects  to  destroy  annually  hundreds  of  millions  of  dollars' 
worth  of  grains  and  fruits  and  vegetables,  and  to  be  solely  responsible  for 
the  dissemination  of  some  of  the  most  serious  diseases  that  make  man  to 
suffer  and  die,  forces  our  attention  whether  we  will  or  not.  Finally,  the 
amazing  variety  and  specialization  of  habit  and  appearance,  the  extraor- 
dinary adaptations  and  "shifts  for  a  living"  which  insects  show,  make  a 
claim  on  the  attention  of  all  who  harbor  the  smallest  trace  of  that  "scientific 
curiosity"  which  leads  men  to  observe  and  ponder  the  ways  and  seeming  of 
Nature.  Some  of  the  most  attractive  and  important  problems  which  modern 
biological  study  is  attacking,  such  as  the  significance  of  color  and  pattern, 
the  reality  of  mechanism  and  automatism  in  the  action  and  behavior  of 
animals  as  contrasted  with  intelligent  and  discriminating  performances 
the  statistical  and  experimental  study  of  variation  and  heredity,  and  other  sub- 
jects of  present-day  biological  investigation,  are  finding  their  most  available 
material  and  data  among  the  insects. 

This  book  is  written  in  the  endeavor  to  foster  an  interest  in  insect  biology 
on  the  part  of  students  of  natural  history,  of  nature  observers,  and  of  general 
readers;  it  provides  in  a  single  volume  a  general  systematic  account  of  all 
the  principal  groups  of  insects  as  they  occur  in  America,  together  with  special 
accounts  of  the  structure,  physiology,  development  and  metamorphoses,  and 
of  certain  particularly  interesting  and  important  ecological  relations  of  insects 
with  the  world  around  them.  Systematic  entomology,  economic  entomology, 
and  what  may  be  called  the  bionomics  of  insects  are  the  special  subjects  of 
the  matter  and  illustration  of  the  book.  An  effort  has  been  made  to  put 
the  matter  at  the  easy  command  of  the  average  intelligent  reader;  but  it  has 
been  felt  that  a  little  demand  on  his  attention  will  accomplish  the  result 
more  satisfactorily  than  could  be  done  with  that  utter  freedom  from  etTort 


vi  Prefatory  Note 

with  which  some  Nature-books  try  to  disseminate  knowledge.  The  few 
technical  terms  used  are  all  explained  in  the  text  in  connection  with  their 
first  use,  and  besides  are  inserted  in  the  Index  with  a  specific  reference,  in 
black-faced  type,  to  the  explanation.  So  that  the  tyro  reading  casually  in 
the  book  and  meeting  any  of  these  terms  apart  from  their  explanation  has 
only  to  refer  to  the  Index  for  assistance.  Readers  more  interested  in  accounts 
of  the  habits  and  kinds  of  insects  than  in  their  structure  and  physiology 
will  be  inclined  lo  skip  the  first  three  chapters,  and  may  do  so  and  still  find 
the  rest  of  the  book  "easy  reading"  and,  it  is  hoped,  not  devoid  of  entertain- 
ment and  advantage.  But  the  reader  is  earnestly  advised  not  to  spare  the 
little  attention  especially  needed  for  understanding  these  first  chapters,  and 
thus  to  ensure  for  his  later  reading  some  of  that  quality  which  is  among 
the  most  valued  possessions  of  the  best  minds. 

In  preparing  such  a  book  as  this  an  author  is  under  a  host  of  obligations 
to  previous  writers  and  students  which  must  perforce  go  unacknowledged. 
Some  formal  recognition,  however,  for  aid  and  courtesies  directly  tendered 
by  J.  H.  Comstock  of  Cornell  University,  whose  entomological  text-books 
have  been  for  years  the  chief  sources  of  knowledge  of  the  insects  of  this 
country,  I  am  able  and  glad  to  make.  To  my  artist.  Miss  Mary  Wellman, 
for  her  constant  interest  in  a  work  that  must  often  have  been  laborious  and 
wearying,  and  for  her  persistently  faithful  endeavor  toward  accuracy,  I  extend 
sincere  thanks.  To  Mrs.  David  Starr  Jordan,  who  read  all  of  the  manuscript 
as  a  "general  reader"  critic,  and  to  President  Jordan  for  numerous  sugges- 
tions I  am  particularly  indebted.  For  special  courtesies  in  the  matter  of 
illustrations  (permission  to  have  electrotypes  made  from  original  blocks) 
I  am  obhged  to  Prof.  F.  L.  Washburn,  State  Entomologist  of  Minnesota  (for 
nearly  one  hundred  and  fifty  figures),  Prof.  M.  V.  Slingerland  of  Cornell 
University,  Dr.  E.  P.  Felt,  State  Entomologist  of  New  York,  Mr.  Wm. 
Beutenmiiller,  editor  of  the  Journal  of  the  New  York  Entomological  Society, 
and  Dr.  Henry  Skinner,  editor  of  the  Entomological  News. 

Vernon  L.  Kellogg. 

Stanford  University,  California, 
June  1,  1904. 


CONTENTS 

CHAP.  PAGE 

I.  The  Structure  and  Special  Physiology  of  Insects i 

II.  Development  and  Metamorphosis  of  Insects 35 

III.  Classification  of  Insects 52 

IV.  The  Simplest  Insects  (Order  Aptera) 58 

V.  May-flies  (Order  Ephemerida)  and  Stone-flies  (Order  Plecoptera).  65 

VI.  Dragon-flies  and  Damsel-flies  (Order  Odonata) 75 

VII.  The  Termites  or  White  Ants  (Order  Isoptera) 99 

VIII.  Book-lice  and  Bark-lice  (Order  Corrodentia),  and  Biting  Bird-lice 

(Order  Mallophaga)  iii 

IX.  The  Cockroaches,  Crickets,  Locusts,  Grasshoppers,  and  Katydids 

(Order  Orthoptera) 123 

X.  The  True  Bugs,  Cicadas,  Aphids,  Scale-insects,  etc.  (Order  Hemip- 

tera),  and  the  Thrips  (Order  Thysanoptera) 163 

XI.  The    Nerve-winged    Insects    (Order    Neuroptera),    Scorpion-flies 

(Order  Mecoptera),  and  Caddis-flies  (Order  Trichoptera) 223 

XII.  The  Beetles  (Order  Coleoptera) 246 

XIII.  The  Two-winged  Flies  (Order  Diptera) 301 

XIV.  The  Moths  and  Butterflies  (Order  Lepidoptera) 358 

XV.  The  Ichneumons,  Gall-flies,  Wasps,  Bees,  and  Ants  (Order  Hymen- 

optera) 459 

XVI.  Insects  and  Flowers 562 

XVII.  Color  and  Pattern  and  their  Uses 583 

XVIII.  Insects  and  Disease 615 

Appendix:  Collecting  and  Rearing  Insects 635 

Index , 649 


AMERICAN    INSECTS 


CHAPTER    I 

THE  STRUCTURE  AND  SPECIAL 
PHYSIOLOGY  OF  INSECTS 

ERHAPS  no  more  uninteresting  matter,  for 
the  general  reader  or  entomological  amateur, 
can  be  written  about  insects  than  a  descrip- 
tive catalogue  of  the  parts  and  pieces  of  the 
insect  body.  And  such  matter  is  practically 
useless  because  it  doesn't  stick  in  the  reader's 
mind.  If  it  is  worth  while  knowing  the 
intimate  make-up  of  a  house-fly's  animated  little  body,  it  is  worth 
getting  this  knowledge  in  the  only  way  that  will  make  it  real,  that  is, 
by  patient  and  eye-straining  work  with  dissecting-needles  and  micro- 
scope. This  book,  anyway,  is  to  try  to  convey  some  information  about 
the  kinds  and  ways  of  insects,  and  to  stimulate  interest  in  insect  life,  rather 
than  to  be  a  treatise  on  insect  organs  and  their  particular  functions.  Life 
is,  to  be  sure,  only  the  sum  of  the  organic  functions,  but  this  sum  or  com- 
bination has  an  interest  disproportionate  to  that  of  any  of  its  component 
parts,  and  has  an  aspect  and  character  which  cannot  be  foretold  in  any  com- 
pleteness from  ever  so  careful  a  disjoined  study  of  the  particular  functions. 
And  so  with  the  body,  the  sum  of  the  organs:  it  is  the  manner  and  seeming 
of  the  body  as  a  whole,  its  symmetry  and  exquisite  adaptation  to  the  special 
habit  of  life,  the  fine  delicacy  of  its  colors  and  pattern,  or,  at  the  other 
extreme,  their  amazing  contrasts  and  hizarrerie,  on  which  depend  our  first 
interest  in  the  insect  body.  A  second  interest,  although  to  the  collector  and 
amateur  perhaps  the  dominant  one,  comes  from  that  recognition  of  the 
differences  and  resemblances  among  the  various  insects  which  is  simply 
the  appreciation  of  kinds,  i.e.,  of  species.  This  interest  expanded  by  oppor- 
tunity and  observation  and  controlled  by  reason  and  the  habit  of  order  and 
arrangement  is,  when  extreme,  that  ardent  and  much  misunderstood  and 
scoffed   at   but   ever-impelling    mainspring  of  the   collector  and   classifier. 


2       The  Structure  and  Special  Physiology  of  Insects 

Of  all  entomologists,  students  of  insects,  the  very  large  majority  are  col- 
lectors and  classifiers,  and  of  amateurs  apart  from  the  few  who  have  "crawl- 
eries"  and  aquaria  for  keeping  alive  and  rearing  "  worms"  and  water-bugs 
and  the  few  bee-keepers  who  are  more  interested  in  bees  than  honey,  prac- 
tically all  are  collectors  and  arrangers.  So,  as  collecting  depends  on  a 
knowledge  of  the  life  of  the  insect  as  a  whole,  and  classifying  (apart  from 
certain  primary  distinctions)  on  only  the  external  structural  character  of 
the  body,  any  detailed  disquisition  on  the  intimate  character  of  the  insec- 
tean  insides  would  certainly  not  be  welcome  to  most  of  the  users  of  this 
book. 

That  insects  agree  among  themselves  in  some  important  characteristics 
and  differ  from  all  other  animals  in  the  possession  of  these  characteristics 
is  implied  in  the  segregation  of  insects  into  a  single  great  class  of  animals- 
Class  here  is  used  with  the  technical  meaning  of  the  systematic  zoologist- 
He  says  that  the  animal  kingdom  is  separable  into,  or,  better,  is  composed 
of  several  primary  groups  of  animals,  the  members  of  each  group  possessing 
in  common  certain  important  and  fundamental  characteristics  of  structure 
and  function  which  are  lacking,  at  any  rate  in  similar  combination,  in  all 
other  animals.  These  primary  groups  are  called  phyla  or  branches-  All 
the  minute  one-celled  animals,  for  example,  compose  the  phylum  Protozoa 
(the  simplest  animals);  all  the  starfishes,  sea-urchins,  sea-cucumbers,  and 
feather-stars,  which  have  the  body  built  on  a  radiate  plan  and  have  no  back- 
bone, and  have  and  do  not  have  certain  various  other  important  things, 
compose  the  phylum  or  branch  Echinodermata;  all  the  back-boned  ani- 
mals and  some  few  others  with  a  cartilaginous  rod  instead  of  a  bony  column 
along  the  back  compose  the  class  Chordata;  all  the  animals  which  have 
the  body  composed  of  a  series  of  successive  rings  or  segments,  and  have 
pairs  of  jointed  appendages  used  as  feet,  mouth-parts,  feelers,  etc.,  aris- 
ing from  these  segments,  compose  the  phylum  Arthropoda.  There  are 
still  other  phyla — but  I  am  not  writing  a  zoology.  The  insects  are  Arthro- 
poda; and  any  one  may  readily  see — it  is  most  plainly  seen  in  such  forms  as 
a  locust,  or  dragon-fly,  or  butterfly,  and  less  plainly  in  the  concentrated 
knobby  little  body  of  a  house-fly  or  bee — that  an  insect's  body  shows  the 
characteristic  arthropod  structure;  it  is  made  up  of  rings  or  segments,  and 
the  appendages,  legs  for  easiest  example,  are  jointed.  An  earthworm's 
body  is  made  up  of  rings,  but  it  has  no  jointed  appendages.  A  worm  is 
therefore  not  an  arthropod.  A  crayfish,  however,  is  made  up  of  distinct 
successive  body-rings,  and  its  legs  and  other  appendages  are  jointed.  And 
so  with  crabs  and  lobsters  and  shrimps.  And  the  same  is  true  of  thousand- 
legged  worms  and  centipeds  and  scorpions  and  spiders.  All  these  creatures, 
then,  are  Arthropods.  But  they  are  not  insects.  So  all  the  back-boned 
animals,   fishes,   amphibians,   reptiles,   birds,  and  mammals  are  Chordates, 


The  Structure  and  Special  Physiology  of  Insects       3 


but  they  are  not  all  birds.  The  phylum  Chordata  is  subdivided  into  or 
composed  of  the  various  classes  Pisces  (fishes),  Aves  (birds),  etc.  And 
similarly  the  phylum  Arthropoda  is  composed  of  several  distinct  classes, 
viz.:  the  Crustacea,  including  the  crayfishes,  crabs,  shrimps,  lobsters, 
water-fleas,  and  barnacles;  the  Onychophora,  containing  a  single  genus 
(Peripatus)  of  worm-like  creatures;  the  Myriapoda,  including  the  thousand- 
legged  worms  and  centipeds;  the  Arachnida,  including  the  scorpions,  spiders, 
mites,  and  ticks;  and  finally  the  class  Insecta  (or  Hexapoda,  as  it  is  some- 
times  called),   whose   members   are   distinguished  from   the   other  Arthro- 

antennae 


•ovipositor 


femuT' 
tibia'' 

tarsal  segments 

Fig.  I. — Locust  (enlarged)  with  external  parts  named. 

pods  by  having  the  body-rings  or  segments  grouped  into  three  regions,  called 
head,  thorax,  and  abdomen,  by  having  jointed  appendages  only  on  the  body- 
rings  composing  the  head  and  thorax  (one  or  two  pairs  of  appendages  may 
occur  on  the  terminal  segments  of  the  abdomen),  and  by  breathing  by  means 
of  air-tubes  (tracheje)  which  ramify  the  whole  interior  of  the  body  and 
open  on  its  surface  through  paired  openings  (spiracles).  The  insects  also 
have  three  pairs  of  legs,  never  more,  and  less  only  in  cases  of  degeneration, 
and  by  this  obvious  character  can  be  readily  distinguished  from  the  Myria- 
pods,  which  have  many  pairs,  and  the  Arachnids,  which  have  four  pairs. 
Centipeds  are  not  insects,  nor  are  spiders  and  mites  and  ticks.  What 
are  insects  most  of  this  book  is  given  to  showing. 

To  proceed  to  the  classifying  of  insects  into  orders  and  families  and 
genera  and  species  inside  of  the  all-including  class  is  the  next  work  of  the 
collector  and  classifier.  And  for  this— if  for  no  other  reason— some  further 
knowledge    of   insect    structure   is    indispensable.     The    classification   rests 


4      The  Structure  and  Special  Physiology  of  Insects 

mostly  on  resemblances  and  differences  in  corresponding  parts  of  the  body, 
apparent  in  the  various  insect  kinds.  What  these  parts  are,  with  their  names 
and  general  characters,  and  what  their  particular  use  and  significance  are, 
may  be  got  partly  from  the  following  brief  general  account,  and  partly  from 
the  special  accounts  given  in  connection  with  special  groups  of  insects  else- 
where in  this  book.  A  little  patience  and  concentration  of  attention  in 
the  reading  of  the  next  few  pages  will  make  the  reader's  attention  to  the 
rest  of  the  book  much  simpler,  and  his  understanding  of  it  much  more 
effective. 

The  outer  layer  of  the  skin  or  body-wall  of  an  insect  is  called  the  cuticle, 
and  in  most  insects  the  cuticle  of  most  of  the  body  is  firm  and  horny  in  char- 


FiG.  2. — Longitudinal  section  of  anterior  half  of  an  insect,  Menopon  titan,  to  show  chitin- 
ized  exoskeleton,  with  muscles  attached  to  the  inner  surface.     (Much  enlarged.) 

acter,  due  to  the  deposition  in  it,  by  the  cells  of  the  skin,  of  a  substance  called 
chitin.  This  firm  external  chitinized  *  cuticle  (Fig.  2)  forms  an  enclosing 
exoskeleton  which  serves  at  once  to  protect  the  inner  soft  parts  from  injury 


Fig.  3.- 


-Bit  of  body-wall,  greatly  magnified,  of  larva  of  blow-fly,  Calliphora  erythrocephala, 
to  show  attachment  of  muscles  to  inner  surface. 


and  to  afford  rigid  points  of  attachment  (Figs.  2,  3  and  4)  for  the  many  small 
but  strong  muscles  which  compose  the  insect's  complex  muscular  system. 
Insects  have  no  internal  skeleton,  although  in  many  cases  small  processes 
project  internally  from  the  exoskeleton,  particularly  in  the  thorax  or  part 

*  It  is  not  certainly  known  whether  the  cuticle  is  wholly  secreted  by  the  skin  cells,  or 
is  in  part  composed  of  the  modified  external  ends  of  the  cells  themselves. 


The  Structure  and  Special  Physiology  of  Insects      5 


of  the  body  bearing  the  wings  and  legs.     Where  the  cuticle  is  not  strongly 

chitinized  it  is  flexible  (Fig.  6),  thus  permitting 

the  necessary  movement  or  play  of  the  rings 

of  the  body,  the  segments  of  the  legs,  antennae 

and  mouth-parts,  and  other  parts.    The  small 

portions  of  chitinized  cuticle  thus  isolated   or 

made  separate  by  the  thin  interspaces  or  sutures 


4.  ■  Fig.  5. 

jri(;_  ^_ — Diagram  of  cross-section  through  the  thorax  of  an  insect  to  show  leg  and  wing 

muscles  and  their  attachment  to  body-wall,  h.,  heart;  al.c,  alimentary  canal;  v.n.c. 

ventral  nerve-cord;  w.,  wing;  /.,  leg;  w.,  muscles.     (Much  enlarged;   after  Graber.) 
PiQ    J — Left  middle  leg  of  cockroach  with  exoskeleton  partly  removed,  showing  muscles. 

(Much  enlarged;   after  Miall  and  Denny.) 

are  called  sclerites,  and  many  of  them  have  received  specific  names,  while 
their  varying  shape  and  character  are  made  use  of  in  distinguishing  and 
classifying  insects. 


Fig.  6. — Chitinized  cuticle  from  dorsal  wall  of  two  body  segments  of  an  insect,  showing 
sutures  (the  bent  places)  between  segmental  sclerites.  Note  that  the  cuticle  is  not 
less  thick  in  the  sutures  than  in  the  sclerites,  but  is  less  strongly  chitinized  (indi- 
cated by  its  paler  color). 

The  whole  body  is  composed  fundamentally  of  successive  segments 
(Figs.  I  and  7),  which  may  be  pretty  distinct  and  similar,  as  in  a  caterpillar 
or  termite  or  locust,  or  fused  together,  and  strongly  modified,  and  hence 
dissimilar,  as  in  a  house-fly  or  honey-bee.  The  segments,  originally  five 
or  six,  composing  the  head,  are  in  all  insects  wholly  fused  to  form  a  single 
box-like  cranium,  while  the  three  segments  which  compose  the  thorax  are 
in  most  forms  so  fused  and  modified  as  to  be  only  with  difficulty  distinguished 
as  originally  independent  body-rings.     On  the  other  hand,  in  most  insects 


6      The  Structure  and  Special  Physiology  of  Insects 

the  segments  of  the  abdomen  retain  their  independence  and  are  more  or 


compound  eye, 
antennae^ 
prothorax^ ' 


labial 
palpi 

proboscis'' 


tarsal  segments 

Fig.  7. — Body  of  the  monarch  butterfly,  Anosia  plexippiis,  with  scales  removed  to  show 
external  parts.     (Much  enlarged.) 

less  similar,  thus  preserving  a  generalized  or   ancestral  condition.      On  the 
head    are   usually   four    pairs    of    jointed    appendages   (Fig.    8),   viz.,    the 

antennae  and  three  pairs  of  mouth-parts, 
known  as  mandibles,  maxillae,  and  labium  or 
under-lip.  Of  these  the  mandibles  in  most 
cases  are  only  one-segmented,  while  the  two 
members  of  the  labial  pair  have  fused  along 
their  inner  edges  to  form  the  single  lip-like 
labium.  The  so-called  upper  lip  or  labrum, 
closing  the  mouth  above,  is  simply  a  fold  of 
the  skin,  and  is  not  homologous,  as  a  true 
appendage  or  pair  of  appendages,  with  the 
other  mouth-parts.  In  some  insects  with  highly 
modified  mouth  structure  certain  of  the  parts 
may  be  wholly  lost,  as  is  true  of  the  mandibles 
in  the  case  of  all  the  butterflies.  The  head 
bears  also  the  large  compound  eyes  and  *  the 
smaller  simple  eyes  or  ocelli  (for  an  account  of 
the  eyes  see  p.  30).  Attached  to  the  thorax  are 
three  pairs  of  legs,  which  are  jointed  appendages, 
homologous  in  origin   and  fundamental  struc- 


FiG.  8. — Dorsal  aspect  of  head 
of  dobson-fly,  Corydalis  cor- 
nuta,  female,  showing  mouth- 
parts.  Ih.,  labrum,  removed; 
md.,  mandible;  mx.,  maxilla; 
li.,  labium;  gl,  glossae  of  la- 
bium; St.,  stipes  of  maxilla; 
mxp.,  palpus  of  maxilla;  ant., 
antenna. 


ture  with  the   mouth-parts  and   antennas,   and  two  pairs  of  wings  (one  or 


The  Structure  and  Special  Physiology  of  Insects      7 

both  pairs  may  be  wanting)  which  are  expansions  of  the  dorso-lateral 
skin  or  body-wall,  and  are  not  homologous  with  the  jomted  ventra 
appendages.  The  thorax  usually  has  its  first  or  most  anterior  segmentl 
the  prothorax,  distinct  from  the  other  two  and  freely  movable,  while 
the  hinder  two,  called  meso-  and  meta-thoracic  segments,  are  usually, 
enlarged  and  firmly  fused  to  form  a  box  for  holding  and  giving  attachment 
to  the  numerous  strong  muscles  which  move  the  wings  and  legs.  The 
abdomen  usually  includes  ten  or  eleven  segments  without  appendages  or 
projecting  processes  except  in  the  case  of  the  last  two  or  three,  which  bear 
in  the  female  the  parts  composing  the  egg-laying  organ  or  ovipositor,  or 


Fig.  9.  Fig.  lo. 

Fig.  9.— Head,  much  enlarged,  of  mosquito,  Culex  sp.,  showing  piercing  and  sucking 
mouth-parts.     (After  Jordan   and   Kellogg.)  ,      tvt  .    .u      u     .  *    „,»i 

Fig    10— Head  and  mouth-parts  of  honey-bee,  much  enlarged.    Note  the  short,  trowel- 
"  like  mandibles  for  moulding  wax  when  building  comb,  and  the  extended  proboscis 
for  sucking  flower-nectar.     (Much  enlarged.) 

in  certain  insects  the  sting,  and  in  the  male  the  parts  called  claspers,  cerci, 
etc.,  which  are  used  in  mating.  On  the  abdomen  are  usually  specially  notice- 
able, as  minute  paired  openings  on  the  lateral  aspects  of  the  segments,  the 
breathing-pores  or  spiracles,  which  admit  air  into  the  elaborate  system  of 
tracheae  or  air-tubes,  which  ramify  the  whole  internal  body  (see  p.  19). 

Of  all  these  external  parts  two  groups  are  particularly  used  in  schemes 
of  classification  because  of  their  structural  and  physiological  importance 
in  connection  with  the  special  habits  and  functions  of  insect  life,  and  because 


8       The  Structure  and  Special  Physiology  of  Insects 


of  the  pronounced  modifications  and  differences  in  their  condition:    these 
are  the  mouth-parts  and  the  wings. 

Insects  exhibit  an  amazing  variety  in  food-habit:  the  female  mosquito  Hkes 
blood,  the  honey-bee  and  butterfly  drink  flower-nectar,  the  chinch-bug  sucks 
the  sap  from  corn-leaves,  the  elm-leaf  beetle  and  maple  worm  bite  and  chew 
the  leaves  of  our  finest  shade-trees,  the  carrion-beetles  devour  decaying 
animal  matter,  the  house-fly  laps  up  sirup  or  rasps  off  and  dissolves  loaf- 
sugar,  the  nut-  and  grain-weevils  nibble  the 
dry  starchy  food  of  these  seeds,  while  the 
apple-tree  borer  and  timber-beetles  find 
sustenance  in  the  dry  wood  of  the  tree- 
trunks.  The  biting  bird-lice  are  content 
with  bits  of  hair  and  feathers,  the  clothes- 
moths  and  carpet-beetles  feast  on  our  :ugs 
and  woolens,  while  the  cigarette-beetle  has 
the    depraved    taste    of   our  modern  vouth. 


Fig.  II. 

Fig.  II. — Mouth-parts,  much  enlarged,  of  the  house-fly,  Musca  domestica.  mx.p.,  maxil- 
lary palpi;    ih.,  labrum;    li.,  labium;    la.,  labellum. 

Fig.  12. — Head  and  mouth-parts,  much  enlarged,  of  thrips.  ant.,  antenna;  lb.,  labrum; 
md.,  mandible;  mx.,  maxilla;  mx.p.,  maxillary  palpus;  li.p.,  labial  palpus;  m.s], 
mouth-stylet.     (After  Uzel;    much  enlarged.) 

With  all  this  variety  of  food,  it  is  obvious  that  the  food-taking  parts  must 
show  many  differences;  one  insect  needs  strong  biting  jaws  (Fig.  8),  another 
a  sharp  piercing  beak  (Figs.  9,  13,  and  14),  another  a  long  flexible  sucking 
proboscis  (Figs.  10  and  16),  and  another  a  broad  lapping  tongue  (Fig.  n). 
Just  this  variety  of  structure  actually  exists,  and  in  it  the  classific  entomolo- 
gist has  found  a  basis  for  much  of  his  modern  classification. 

Throughout  all  this  range  of  mouth  structure  the  insect  morphologists 
and  students  of  homology,  beginning  with  Savigny  in  18 16,  have  been  able 
to  trace  the  fundamental  three  pairs  of  oral  jointed  appendages,  the  mandi- 
bles, maxillae,  and  labium.  Each  pair  appears  in  widely  differing  condi- 
tions; the  mandibles  may  be  large  strong  jaws  for  biting  and  crushing,  as 
with  the  locust,  or  trowel-like,  for  moulding  wax,  as  with  the  honey-bee,  or 


The  Structure  and  Special  Physiology  of  Insects      9 


long,  flat,  slender,  and  saw-toothed,  as  with  the  scorpion-flies,  or  needle-like, 
as  in  all  the  sucking  bugs,  or  reduced  to  mere  rudiments  or  wholly  lacking, 
as  in  the  moths  and  butterflies.  Similarly  with  the  other  parts.  But  by 
careful  study  of  the  comparative  anatomy  of  the  mouth  structure,  and  par- 
ticularly by  tracing  its  development  in  typical  species  representing  the 
various  types  of  biting,  sucking,  and  lapping  mouths,  all  the  various  kinds  of 
mouth  structure  can  be  compared  and  the  homologies  or  structural  cor- 
respondences of  the  component  parts  determined.     Figs.  8  to  16  illustrate 


-mxp. 


Fig.  13.  Fig.  14. 

Fig.   13. — Seventeen-year  cicada,   Cicada  septcndecim,  sucking  sajj  from  twig.      (After 

Quaintance;    natural  size.) 
Fig.  14. — Section  of   twig  of  Carolina  poplar  showing  beak  of  cicada  in  position  when 

sucking.     (After  Quaintance;   much  enlarged.) 
Fig.    15. — Mouth-parts,    much    enlarged,    of   net-winged   midge,    Bibicocephala   doanei, 

female,     md.,   mandible;    mx.,   maxilla;    tnx.L,    maxillary    lobe;    mx.p.,   maxillary 

palpus;    //.,  labium;    hyp.,  hypopharynx;    pg.,  paraglossa  of  labium;    l.ep.,  labrum 

and  epipharynx. 

examples  of  different  mouth  structures,  with  the  corresponding  parts  similarly 
lettered. 

The  most  conspicuous  structural  characteristic  of  insects  is  their  poses- 
sion  of  wings.  And  the  wings  undoubtedly  account  for  much  of  the  success 
of  the  insect  type.  Insects  are  the  dominant  animal  group  of  this  age,  as 
far  as  number  of  species  constitutes  dominance,  their  total  largely  sur- 
passing that  of  the  species  of  all  the  other  kinds  of  living  animals.  Flight 
is  an  extremely  effective  mode  of  locomotion,  being  swift,  unimpeded  by 
obstacles,  and  hence  direct  and  distance-saving,  and  an  animal  in  flight 
is  safe  from  most  of  its  enemies.  The  wings  of  insects  are  not  modified  true 
appendages  of  the  body,  but  arise  as  simple  sac-like  expansions  (Fig.  17) 
of  the  body-wall  or  skin  much  flattened  and  supported  by  a  framework  of 


lo     The  Structure  and  Special  Physiology  of  Insects 


^ 


strongly  chitinized  lines  called  veins.     These  veins  are  corresponding  cutic- 

ular  thickenings,  in  the  upper  and  lower  walls  of 
the   flattened   wing-sac,  which   protect,  while  the 
wing  is  forming,  certain  main  tracheal  trunks  that 
carry  air  to  the   wing-tissue.     After  the   wing  is 
expanded  and  dry,  the  tracheae  mostly  die  out,  and 
the  veins  are  left  as  firm  thick-walled  branching 
tubes   which   serve    admirably    as    a  skeleton   or 
framework  for  the  thin  membranous  wings.       It 
has    been   found  that   despite  the   obvious   great 
variety  in  the  venation,  or  number  and  arrange- 
ment of  these  veins  of  the  wing,  a  general  type- 
plan  of  venation  is  apparent  throughout  the  insect 
class.   The  more  important  and  constant  veins  have 
been   given  names,  and  their  branches   numbers 
(Fig.    i8).      By  the   use    of   the    same   name    or 
number  for  the  corresponding  vein  throughout  all 
the  insect  orders,  the  homologies  or  morphological 
correspondences  of  the  veins  as  they  appear  in  the 
variously  modified  wings  of   the  different  insects 
are  made  apparent.    Many  figures  scattered  through 
this  book  show  the  venation  of  insects  of 
different  orders,  and  the  corresponding 
lettering  and  numbering  indicate  the 
homologies  of  the  veins.     As  the  wing 
venation  presents  differing  conditions 
readily  noted  and  described,  much  use  is 
made  of  it  in  classification. 

The  differences  in  the  wings  them- 
selves, that  is,  in  number,  relative  size 
of  fore  and  hind  wings,  and  in  struc- 
ture, i.e.,  whether  membranous  and 
delicate,  or  horny  and  firm,  etc.,  have 

,     ,      .  ,       .     always  been   used    to  distinguish    the 

Fig.  i6. — Sphinx  moth,  showing  proboscis;  -^  ^  r    ■ 

at  left  the  proboscis  is  shown  coiled  up  larger  groups,  as  orders,  of  msects, 
on  the  under  side  of  the  head,  the  nor-  ^nd  the  first  classification,  that  of 
mal  position  when  not  in  use.     (Large  _  .  ,  \    j-    -j       i.i.       i 

figure,  one-half  natural  size;  small  fig-  Lmnsus  (1750  app.),  divides  the  class 
ure,  natural  size.)  into    orders   almost   solely  on   a  basis 

of  wing   characters.     The  ordinal  names  expressed,   to   some   degree,   the 
differences,  as  Diptera,*  two-winged;  Lepidoptera,  scale-winged;  Coleoptera, 
sheath-winged,  and  so  on.     As  a  matter  of  fact,  there  may  be  much  differ- 
*  The  derivation  of  the  Lianaean  ordinal  names  is  given  on  p,  223. 


Fig.   16. 


The  Structure  and  Special  Physiology  of  Insects    1 1 


ence  in  the  wings  within  a  single  order;  most  beetles,  for  example,  have 
four  wings,  but  some  have  two  and  some  none.  There  are  indeed  wingless 
species  in  almost  every  insect  order.  But  a  typical  beetle  has  quite  dis- 
tinctive and  commonly  recognized  wing  characters;  that  is,  it  has  two  pairs 
of  wings,  the  fore  pair  being  greatly  thickened,  and  developed  to  serve  as 
sheaths  for  the  larger,  membranous  under-pair,  which  are  the  true  flight 
wings.     Similarly,  practically  all  moths  and  butterflies  have  two  pairs  of 


Ik     \ 


Fig.  17.  Fig.  li 

Fig.  17. — Wing  of  cabbage-butterfly,  Pieris  rapa,  in  early  sac-like  stage,    tr.,  trachea; 

//.,  tracheoles;    l.v.,  lines  of    future  veins.     (After  Mercer;    greatly  magnified.) 
Fig.  18. — Diagram  of  wings  of  monarch  butterfly,  Anosia  plexippits,  showing  venation. 

c,  costal  vein;   s.c,  subcostal  vein;   r.,  radial  vein;   cii.,  cubital  vein;  a.,  anal  veins. 

In  addition,  most  insects  have  a  vein  lying  between  the  subcostal  and  radial  veins, 

called  the  median  vein.     (Natural  size.) 

membranous  wings  completely  covered  above  and  below  by  small  scales, 
which  give  them  their  distinctive  color  and  pattern. 

The  exoskeleton,  or  cuticle,  of  the  insect  body  is  sometimes  nearly 
smooth  and  naked,  but  usually  it  is  sculptured  by  grooves  and  ridges,  punc- 
tures or  projections,  and  clothed  with  hairs  or  those  modified  flattened  hairs 
known  as  scales  (especially  characteristic  of  butterflies  and  moths).  This 
clothing  of  hairs  or  scales,  or  the  skin  itself,  is  variously  colored  and  pat- 
terned, often  with  the  obvious  use  of  producing  protective  resemblance  or 
mimicry,  but  often  without  apparent  significance.  (For  an  account  of  the  colors 
and  patterns  of  insects  and  their  uses  see  Chapter  XVII.)  The  hairs  may  serve 
for  protection,  or  may  be  tactile  organs,  or  even  organs  of  hearing  (see  p.  26). 
The  projecting  processes  may  be  spines  or  thorns  or  curious  and  inexplicable 


I  2    The  Structure  and  Special  Physiology  of  Insects 

knobs  and  horns.     The  rhinoceros-beetle  (Dynastes)  (Fig.  19)  and  the  sacred 
scarabeus  are  famihar  examples  of  insects  with  such  prominent  processes. 

The  insect  body,  as  a  whole,  appears  in  great  variety  of  form  and  range 
of  size,  as  our  knowledge  of  the  variety  of  habit  and  habitat  of  insects  would 
lead  us  to  expect.  In  size  they  vary  from  the  tiny  four-winged  chalcids 
which  emerge,  after  their  parasitic  immature  life,  from  the  eggs  of  other 
.nsects,  and  measure  less  than  a  millimeter  in  length,  to  the  giant  Phasmids 


«£r 


Fig.  19. — Rhinoceros-beetle,  Dynastes  tityriis,  showing  chitinous  horns. 

(walking-sticks)  of  the  tropics,  with  their  ten  or  twelve  inches  of  body  length, 
and    the    great   Formosan    dragon-flies   with   an   expanse    of   wing   of   ten 
inches.     A  Carboniferous  insect  like  a  dragon-fly,  known  from  fossils  found 
at    Commentry,    France,   had    a   wing   expanse   of    more    than    two    feet. 
Insects  show  a  plasticity  as  to  general  body  shape  and  appearance  that  results 
in  extreme  modifications  corresponding  with  the  extremely  various  habits 
of  life  that  obtain  in  the  class.     Compare  the  delicate  fragility  of  the  gauzy- 
winged  May-fly  with  the  rigid  e.xoskeleton  and  horny  wings  of  the  water- 
beetle;    the  long- winged,  slender-bodied  flying-machine  we  call    a   dragon- 
fly with  the  shovel-footed,  half-blind,  burrowing  mole-cricket;    the  plump, 
toothsome  white  ant  that  defends  itself  by  simple  prolificness  with  the  spare, 
angular,  twig-like   body   of   the   walking-stick   with   its   effective   protective 
resemblance  to  the  dry  branches  among  which  it  lives.     Compare  the  leg- 
less, eyeless,  antennaless,  wingless,  sac-like  degraded  body  of  the  orange- 
scale  with  the  marvelous  specialization  of  structure  of  that  compact  expo- 
nent of  the  strenuous  insect  life,  the  honey-bee;  contrast  the  dull  colors  of  the 
lowly  tumble-bug  with  the  flashing  radiance  of  the  painted   lady-butterfly. 
But  through  all  this  variety  of  shape  and  pattern,  complexity  and  degenera- 
tion, one  can  see  the  simple  fundamental  insect  body-plan;    the  successive 
segments,  their  grouping  into  three  body-regions,  the  presence  of  segmented 
appendages  on  head   and   thorax  and  their  absence  on  abdomen   (e.xcept 
perhaps  in  the  terminal  segments),  and  the  modification  of  these  append- 
ages into  antennae  and  mouth-parts  on  the  head,  legs  on  the  thorax,  and 
ovipositor,  sting,  or  claspers  in  the  abdomen. 

In  the  character  of  the  structure  and  functions  of  the  internal  organs 


The  Structure  and  Special  Physiology  of  Insects     i  3 


or  systems  of  organs  of  insects,  a  special  interest  attaches  to  the  conditions 
shown  by  the  circulatory  and  respiratory  systems,  and  by  the  special  sense- 


s.ijl. 

Fig.  20. — Diagram  of  lateral  interior  view  of  monarch  butterfly,  Anosia  plexippus,  show- 
ing the  internal  organs  in  their  natural  arrangement,  after  the  removal  of  the  right 
half  of  the  body-wall  together  with  the  tracheje  and  fat  body;  I  to  III,  segments 
of  the  thorax;  i  to  g,  segments  of  the  abdomen.  Alimentary  Canal  and  Appen- 
dages: ph.,  pharynx;  sd.  and  sgl.,  salivary  duct  and  gland  of  the  right  side;  oe., 
oesophagus;  f.r.,  food -reservoir;  St.,  stomach;  i.,  small  intestine;  c,  colon;  r.,  rec- 
tum; a.,  anus;  m.v.,  Malpighian  tube.  Haemal  System:  h.,  heart  or  dorsal  vessel; 
ao.,  aorta;  a.c,  aortal  chamber;  Nervous  System  (dotted  in  figure):  br.,  brain; 
g.,  subcesophageal  ganglion;  l.g.,  compound  thoracic  ganglia;  fl,g.,,  ag.^,  first  and 
fourth  abdominal  ganglia.  Female  Reproductive  Organs:  cp.,  copulatory  pouch; 
v.,  vagina;  o.,  oviduct,  and  oo.,  its  external  opening;  r.ov.,  base  of  the  right  ovarian 
tubes  turned  down  to  expose  the  underlying  organs;  l.ov.,  left  ovarian  tubes  in  posi- 
tion, and  ov.c,  their  termination  and  four  cords;  sp.,  spermatheca;  a.gl.^,  part 
of  the  single  accessory  gland;  a.gl.^,  one  of  the  paired  accessory  glands;  only  the 
base  of  its  mate  is  shown.  Head:  a.,  antenna;  mx.,  proboscis,  p.,  labial  palpus. 
(After  Burgess;    three  times  natural  size.) 

organs  and  their  manner  of  functioning.  The  muscular  system  varies  from  the 
.simple  worm-like  arrangement  of  segmentally  disposed  longitudinal  and 
ring  muscles  possessed  by  the  caterpillars,  grubs,  and  other  worm-like  larvae, 
to  the  complicated  system  of  such 
specialized  and  active  forms  as  the 
honey-bee  and  house-fly.  Lyonnet 
describes  about  two  thousand  dis- 
tinct muscles  in  the  caterpillar  'of 
the  goat-moth.  Insect  muscles  are 
similar,  in  their  finer  structure,  to 
those  of  other  animals,  most  of  Fig.  21. — Bit  of  muscle  of  a  biting  bird-louse, 
them  being  composed  of  finely  Eurymetopus  tatcrus.  (Greatly  magnified.) 
cross-striated  fibers  (Figs.  21  and  22)  held  together  in  larger  or  smaller 
masses  and  attaching  to  the  rugosities  of  the  inner  surface  of  the  exo- 
skeleton.  The  muscle  substance,  when  fresh,  is  peculiarly  transparent 
and  delicate-looking,  but  it  has  great  contractile  power. 

The  alimentary  canal  (Figs.  23-27),  like  that  of  other  animals,  is  a  tube 
but  little  longer  than  the  body  in  flesh-eating  forms,  and  much  longer  in 
plant-feeders;  it  runs,  more  or  less  curving  and  coiled,  through  the  body 
from  mouth  to  anal  opening,  which  lies  in  the  last  segment  of  the  abdomen. 


14    The  Structure  and  Special  Physiology  of  Insects 
This   tube  is   expanded   variously  to   form  crop,  gizzard,  or  stomach,  and 


Fig.  22. — Diagrammatic  figures  of  bits  of  insect  muscle,  variously  treated. 
Gehuchten;    greatly  magnified.) 


(After  Van 


Fig.  23.  —  Alimentary 
canal  of  a  locust.  At 
upper  end  the  oesoph- 
agus, then  the  ex- 
panded crop,  then  sev- 
eral large  gastric  coeca, 
then  the  true  stomach, 
the  thread-like  Malpig- 
hian  tubules,  the  bent 
intestine,  and  the  ex- 
panded rectum.  (After 
Snodgrass;  enlarged.) 


contracted  elsewhere  to  be  oesophagus  or  intestine. 
One  or  two  pairs  of  saHvary  glands  pour  their  fluid  into 
the  mouth,  while  the  digesting  stomach  or  ventriculus 
usually  possesses  two  or  more  pairs  of  diverticula  known 
as  gastric  coeca,  which  are  lined  with  glands  believed 
to  secrete  special  digestive  fluids.  Neither  liver 
nor  kidneys  are  present  in  the  insect  body,  but  the 
secretory  function  of  the  latter  are  undertaken  by  a 
number  of  usually  long  thread-like  tubular  diverticula 
of  the  intestine  known  as  Malpighian  tubules.  The 
intestine  itself  is  usually  obviously  made  up  of  three 
successive  parts,  a  large  intestine,  small  intestine, 
and  rectum.  There  are  also 
present  not  infrequently  in- 
testinal ca?ca. 

Two  striking  peculiarities 
about  the  reproductive  system 
of  insects  are  the  possession 
by  the  female  of  one  or  more 
spermathecce  (Fig.  66,  r.s.)  in 
which  the  male  fertilizing 
cells,  the  spermatozoa,  are  re- 
ceived and  held,  and  the  com- 
pletion of  all  the  envelopes  of  „  t^-  ..  r 
^  ....  ,  Fig.  24. — Dissection  of 
the  egg,  mcludmg  the  outer  cockroach  to  show  {al.c.) 
hard  shell,  before  its  specific  alimentary  canal.  (After 
.  ...  .  ,  ,  T^  Hatschek  and  Cori:  twice 
fertilization  takes  place,    rer-        natural  si^e.) 


The  Structure  and  Special  Physiology  of  Insects    i  5 


tilization  is  itself  accomplished  in  the  lower  end  of  the  egg-duct  just  before  the 
egg  is  laid,  by  the  escape  of  spermatozoa  from  the  spermatheca  (the  female 


sff. 


ml. 


int. 


Fig.  25.  Fig.  26. 

Fig.  25. — Alimentary  canal  of  larva  of  harlequin-fly  (Chironovius  sp.).  oes.,  oesophagus; 
s.g.,  salivary  gland;  ca.,  cardiac  chamber  of  stomach;  mt.,  Malpighian  tubules;  ch., 
intestinal  chamber;  si.,  small  intestine;  col.,  colon.  (After  Miall  and  Hammond; 
much  enlarged.) 

Fig.  26. — AUmentary  canal  of  two  species  of  thrips;  at  left  Trichothrips  copiosa,  male, 
at  right  Aelothrips  fasciata.  sal.g.,  saHvary  gland;  oes.,  oesophagus;  prov.,  proven- 
triculus;  vent.,  ventriculus;  m.t.,  Malpighian  tubules;  int.,  intestine;  rec,  rectum. 
(After  Uzel;    greatly  enlarged.) 

having  of  course  previously  mated)  and  their  entrance  into  the  egg  through  a 
tiny  opening,  the  micropyle  (Fig.  67),  in  the  egg-shell  and  inner  envelopes. 
A  queen  bee  mates  but  once,  but  she  may  live  for  four  or  five  years  after 
this  and   continue   to    lay  fertilized   eggs   during   all  this  time.      She  must 


1 6    The  Structure  and  Special  Physiology  of  Insects 

receive  several  million  spermatozoa  at  mating,  and  retain  them  alive  in  the 
spermatheca  during  these  after-years. 


proTi- 


FiG.  27. — Alimentary  canal  of  dobson-fly,  Cor)'(fa/wconi?</a.  A,  larva;  B,  adult;  C,  pupa; 
oes.,  oesophagus;  prov.,  proventriculus;  g.c,  gastric  coeca;  vent.,  ventriculus;  r.g., 
reproductive  gland;  vi.t.,  Malpighian  tubules;  int.,  intestine;  iut.c,  intestinal 
coecum;    rec,  rectum;    drg.,  oviduct.     (After  Leidy;    twice  natural  size.) 

The  circulatory  system  of  insects  presents  two  particular  features  of  inter- 
est in  that  the  blood  does  not,  as  in  our  bodies,  carry  oxygen  to  the  tissues,  and 


Fig.    28. — Cross-section  and   longitudinal  section   of  salivary  gland  of   giant  crane-fly, 
Holorusia  rubiginosa.     (Greatly  magnified.) 

that  there  is  a  contractile  pulsating  heart-like  organ,  but  no  arteries  or  veins. 
The  so-called  heart  is  a  delicate-walled,  narrow,  subcylindrical  vessel  com- 
posed of  a  series  of  most  commonly  from  three  to  eight  successive  cham- 
bers lying  longitudinally  along  the  median  line  just  underneath  the  dorsal 
wall  of  the  abdomen  and  thorax  (Figs.  30  and  31).  Each  chamber  opens, 
guarded  by  a  simple   valvular  arrangement  (Fig.  33),  into  the   chambers 


The  Structure  and  Special  Physiology  of  Insects     17 
behind  and  before  it,  the  posterior  one  being  closed  behind  and  the  anterior 


Fig.  29. — Cells  of  digestive  epithelium  of  stomach  (ventriculus)  of  crane-fly,  Ptychoptera 
sp.,  showing  secretion  of  digestive  fluids,  or  expulsion  of  cell-content.  (After  Van 
Gehuchten;   greatly  magnified.) 

one  extending  forward  into  or  near  the  head  as  a  narrowed  tubular  anterior 
portion,  which  is  sometimes  called  the 
aorta.  From  the  anterior  open  end  of 
this  aorta  the  blood,  forced  by  pulsations 
of  the  heart-chambers,  which  proceed 
rhythmically  from  the  posterior  one 
forward,  pours  out  into  the  body-cavity, 
proceeding  in  more  or  less  regular  cur- 
rents or  paths,  but  never  enclosed  in 
arterial  vessels,  bathing  all  the  tissues, 
and  carrying  food  to  them.  Finally 
taking  up  fresh  supplies  of  food  by  bath- 
ing the  food-absorbing  walls  of  the 
alimentary  canal,  it  enters  the  chambers 
of  the  heart  through  lateral  openings  in 
these  (either  at  the  middle  or  anterior  end 
of  each),  which  thus  estabhsh  communi- 
cation between  the  body-cavity  and  heart-  Fig.  30.  Fig.  31. 
The  blood  receives  no  more  oxygen  than  Fig.  30.— Diagram  of  circulatory 
it  needs  for  its  own  use,  and  thus  does  ^^^gX  t  mrchimS'dis'al 
not  play  nearly  so  complex  a  function  in  vessel,  or  heart,  with  single  artery. 
the   insect's   body  as    in    ours.      And  this        Ar^ws^mdicate^direc^on  „,  blood- 

simplicity  of  function  probably  explains    pj^    31.— Dissection  showing   dorsal 

in  some  degree  the  extreme  primitiveness       vessel,    or    heart,    of  locust,   Dis- 
,^  .    ,         .        ,^  ,  sostezra  Carolina.     (After Snodgrass; 

of  the  make-up  of  the  circulatory  system.        ^^j^^  natural  size.) 

It     will    be     seen    that    the    respiratory 

system,  on  the   other  hand,  is    particularly  highly  developed,  as  it  devolves 


I  8    The  Structure  and  Special  Physiology  of  Insects 


Fig.  32. 


Fig.  33. 


Fig.  32. — Portion  of  dorsal  vessel  and  pericardial  membrane  of  locust,  Dissosteira  caro* 

Una.     (After  Snodgrass;    greatly  magnified.) 
Fig.  33. — Cross-section  of  dorsal  vessel  or  heart  in  pupa  of  tussock-moth,  Hemerocampa 

leiicostigma,  showing  valves.     (Greatly  magnified.) 


:;^sp 


Fig.  34. 


Fig.  35. 


Fig.  36. 


Fig.  34. — Diagram  of  tracheal  system  in  body  of  beetle,    sp.,  spiracles;  tr.,  tracheae. 

(After  Kolbe.) 
Fig.  35. — Diagram  showing  main  tracheae  in  respiratory  system  of  locust,  Dissosteira 

Carolina.     (After  Snodgrass;    twice  natural  size.)  • 

Fig.  36. — Diagram   showing  respiratory  system  in  thripf.    St.,  spiracles.     (After  Uzel; 

much  enlarged.) 


The  Structure  and  Special  Physiology  of  Insects    1 9 

on   it  not  merely  to   take  up  oxgyen  from  the  outer  air  and  give  up  the 

waste  carbon  dioxide  of  the 
body,  but  also  to  convey  these 
gases  to  and  from  all  the  tis- 
sues of  the  body.  The  blood 
is  not  red,  but  pale  yellowish 
or  greenish,  and  is  really  more 
like  the  lymph  of  the  ver- 
tebrate body  than  like  its 
blood 

Insects  do  not  breathe 
through  the  mouth  or  any 
openings  on  the  head,  but  have  ' 
a  varying  number  (usually 
from  two  to  ten  pairs)  of 
small  paired  openings  on  the 
sides  of  the  thorax  and  abdo- 
men. These  openings,  called 
spiracles,  or  stigmata,  are  ar- 
ranged segmentally  and  in 
most  insects  are  to  be  found 
on  two  of  the  thoracic  seg- 
ments and  on  all  the  abdomi- 
nal segments  except  the  last  two  or  three.  The  openings  are  euarded  by  fine 
hairs  or  even  little  valvular  lids  to  prevent 
the  ingress  of  dust,  and  are  the  entrances  to 
an  extended  system  of  delicate  air-tubes  or 
tracheae  which  branch  and  subdivide  until 
the  whole  of  the  internal  body  is  reached 
and  ramified  by  fine  capillary  vessels  bring- 
ing fresh  air  to  all  the  tissues  and  carrying 
off  the  waste  carbon  dioxide  made  by  the 
metabolism  of  these  tissues.  The  usual 
general  arrangement  of  this  elaborate  re- 
spiratory system  is  shown  in  Figs.  34,  35, 
and  36.  Short  broad  trunks  lead  from 
each  spiracle  to  a  main  longitudinal  trunk 
on   each   side    of   the   body,   from  which  _^^^m. 

numerous  branches    arise,  these   going  to  iS^^! 

particular  regions   of   the  body  (Fig.    38)     Fig.  39— i'lcce  of  trachea  (air-tube), 
,       ,  ,  ,  .  »  .    ji  .M  greatly  magnified,  showing  spiral 

and     there     branchmg    \epeatedly    until        e^^^^j    (t^nidia).     (Photomicro- 

even    individual    cells    get     special    tiny         graph  by  George  O.  Mitchell.) 


Fig.   37 


Fig.  37. — Diagram  showing  respiratory  system  of  pupa 
of  mealy -winged  fly,  Akyrodes  sp.;  only  two  pairs 
of  spiracles  are  present.  (After  Bemis;  much 
enlarged.) 

Pig  28. — Diagram  of  trachese  in  head  of  cockroach. 
Note  branches  to  all  mouth-parts,  and  the  an- 
tennae. /.,  tracheae,  or  air-tubes.  (After  Miall 
and  Denny.) 


20    The  Structure  and  Special  Physiology  of  Insects 


respiratory  capillaries.  The  tracheae  are  readily  recognized  under  the  micro- 
scope by  their  finely  transversely  ringed  or  striated  appearance  (Fig.  39). 
These  transverse  "rings"  are  really  spirally  arranged  short  chitinized 
thread-like  thickenings  on  the  inner  w^all  of  the  tube,  which  by  their  elasticity 
keep  the  delicate  air-tubes  open.     The  tubes  are  filled  and  emptied  by  a 

rhythmic  alternately  contracting  and  expanding 
movement  of  the  abdomen,  called  the  respiratory 
movement.  When  the  ring-muscles  contract,  the 
walls  of  the  abdomen  are  squeezed  in  against 
the  viscera,  which,  compressing  the  soft  air-tubes, 
force  the  air  out  of  them  through  the  spiracles; 
when  the  body-walls  are  allowed  to  spring  back 
to  normal  position  fresh  air  rushes  in  through  the 
spiracles  and  fills  up  the  air-tubes,  which  expand 
because  of  the  elastic  spiral  thickenings  in  their 
walls.  Insects  which  live  in  water  either  come 
up  to  the  surface  to  breathe  and  in  some  cases 
to  take  down  a  supply  of  air  held  on  the  outside 
of  the  body  by  a  fine  pubescence  like  the  pile  of 
velvet,  or  they  are  provided  with  tracheal  gills 
(Fig.  40)  which  enable  them  to  breathe  the  air 
mixed  with,  or  dissolved  in,  the  water.  Gillcd 
insects  do  not,  of  course,  have  to  come  to  the 
surface  to  breathe.  The  gills  may  be  thin  plate- 
like flaps  on  the  sides  or  posterior  tip  of  the 
body,  or  may  be  tufts  of  short  thread-like  tubes 
variously  arranged  over  the  body.  Or  they 
may  be,  as  in  the  dragon-fly  nymphs,  thin  folds  along  the  inner  wall  of  the 
rectum,  the  water  necessary  to  bathe  them  being  taken  in  and  ejected  again 
through  the  anal  opening.  In  all  cases  these  insect  gills  differ  from  those 
of  other  animals,  as  crabs  and  fishes,  in  that  they  are  not  organs  for  the 
purification  of  the  blood,  i.e.,  effecting  an  exchange  of  carbon  dioxide  and 
oxygen  carried  by  it,  but  are  means  for  an  osmotic  exchange  of  the  fresh 
air  dissolved  in  water  for  carbon-dioxide-laden  air  from  air-tubes  or  tracheae 
which  run  out  into  the  gills.  Probably  no  more  blood  enters  these  gills 
than  is  necessary  to  bring  food  to  them.  Impure  air  is  brought  to  them 
by  air-tubes,  and  exchanged  by  osmosis  through  the  thin  walls  of  air-tube 
and  giU-membrane  for  fresh  air,  which  passes  from  these  gill  air-tubes  to 
the  rest  of  the  respiratory  system  of  the  body. 

The  nervous  system  of  insects  shows  the  fundamentally  segmental  make-up 
of  the  body  better  than  any  of  the  other  systems  of  internal  organs,  although 
probably  in  the  successive  chambers  of  the  dorsal  vessel  or  heart,  and  certainly 


Fig.  40. — Young  (nymph)  of 
May-fly  showing  {g.)  tra- 
cheal gills.  (After  Jenkins 
and  Kellogg.) 


The  Structure  and  Special  Physiology  of  Insects    21 

in  the  paired  arrangement  of  the  spiracles  and  tracheal  trunks  leading  from 
them,  a  segmental  condition  is  obvious.     The  central  nervous  system  consists 


^h. 

ant. 

% 

ibxes, 
saLgl  .    "-,, 
i.b.wg.-       •-// 
br.  _           I' 

...A 

i.bjnsi.    -E 

"'''  i.b.h.-::.:::ff 

^J^\ 

i.b.mt.l.-//W\] 

^'^'"^^ 

prov. iw^ 

^iM 

susp. /fl- -- 

9'C-  - |-|^ 

P'^"^ 

vent jfl 

£-3 

ir. 11/ 

ad.tis yF\ 

ma  I.  tub.  yi^:^--- 


FiG.  41. — Larva  of  giant  crane-fly,  Holorusia  riibiginosa.  A,  entire;  B,  dissected,  show- 
ing all  organs  except  the  muscles  and  ventral  nerve-chain,  h.,  head;  ant.,  anterina; 
i.b.res.,  imaginal  bud  of  pupal  respiratory  tube;  i.b.wg.,  imaginal  bud  of  wing; 
i.b.ms.L,  imaginal  bud  of  mesothoracic  leg;  i.b.h.,  imaginal  bud  of  balancer; 
i.b.mt.L,  imaginal  bud  of  metathoracic  leg  (the  imaginal  buds  of  fore  legs  are  con- 
cealed by  head-capsule);  sal.gl.,  salivary  gland  (the  other  salivary  gland  is  removed); 
br.,  brain;  ces.,  oesophagus;  prov.,  proventriculus;  susp.,  suspensorium;  g.c,  gastric 
coecum;  vent.,  ventriculus;  tr.,  trachea;  ad.tis.,  adipose  tissue;  mal.tub.,  Malpi- 
ghian  tubule;  d.v.,  dorsal  vessel;  w.m.,  wing-muscles  of  pericardium;  sm.int., 
small  intestine;  tes.,  testis;  ini.c,  intestinal  csecum;  v.d.,  vas  deferens;  Lint.,  large 
intestine;    sp.,  spiracle;    term.pr.,  terminal  processes.     (Twice  natural  size.) 


of  a  brain  and  a  ventral  chain  of  pairs  of  ganglia  segmentally  arranged  and 
connected  by  a  pair  of  longitudinal  cords  or  commissures  (Figs.  42,  43,  44). 
The  two  members  of  each  of  the  pairs  of  ganglia  as  well  as  of  the  pair  of 


22    The  Structure  and  Special  Physiology  of  Insects 


Fig.  42.  Fig.  43.  Fig.  44. 

Fig.  42. — Diagram  of  ventral  nerve-cord  of  locust,  Dissosteira  Carolina.     (After  Snod- 

grass;    twice  natural  size.) 
Fig.    43. — Diagram   of   the    nervous   system   of   the   house-fly.     (After   Brandt;     much 

enlarged.) 
Fig.  44. — Nervous  system  of  a  midge,  CJuronomus  sp.     (After  Brandt,  much  enlarged.) 

commissures  are  in  most  insects  more  or  less  fused  to  form  single  ganglia 
and  a  single  commissure,  but  in  others  the  commissures, 
at  least,  are  quite  distinct.  In  the  simpler  or  more 
generalized  condition  of  the  nervous  system  as  seen 
in  the  simpler  insects  and  the  larvae  of  the  higher 
ones  there  are  from  three  or  four  to  seven  or  eight 
abdominal  ganglion  pairs,  one  pair  to  a  segment,  a 
pair  in  each  of  the  three  thoracic  segments,  and  one 
in  the  head  just  under  the  oesophagus.  From  this 
ganglion  (or  fused  pair)  circumoesophageal  commis- 
sures run  up  around  the  oesophagus  to  an  important 
ganglion  (also  composed  of  the  fused  members  of  a 
pair)  lying  just  above  the  oesophagus  and  called  the 
brain,  or  supraoesophageal  ganglion  (Figs.  45,  46,  and 
47).  From  this  proceed  the  nerves  to  those  impor- 
tant organs  of  special  sense  situated  on  the  head,  the 
antennae  and  eyes.  From  the  suboesophageal  gan- 
lion    nerves    run   to    the  mouth-parts,  from   the  thoracic   ganglia    to    the 


Fig.  45. — Brain,  com- 
pound eyes,  and  part 
of  sympathetic  nerv- 
ous system  of  locust, 
Dissosteira  Carolina. 
(After  Snodgrass; 
greatly  magnified.) 


The  Structure  and  Special  Physiology  of  Insects    23 

wings  and  legs  and  the  complex  thoracic  muscular  system,  while  from 
the  abdominal  ganglia  are  innervated  the  abdominal  muscles  and  sting, 
ovipositor,  or  male  claspers.  In  addition  to  this  main  or  ventral  nervous 
system  there  is  a  small  and  considerably  varying  sympathetic  system  (Figs. 
46  and  48)  to  which  belong  a  few  minute  ganglia  sending  nerves  to  those 
viscera  which  act  automatically  or  by  reflexes,  as  the  alimentary  canal  and 
heart.     This  sympathetic  system  is  connected  with  the  central  or  principal 


Fig.  46. 

Fig.  46. — Brain,  circumcesophageal  commissures,  and  subcesophageal  ganglion  of  the 
red-legged  locust,  Melanophis  jemur-rubrum.  oc,  ocellus;  op.n.,  optic  nerve;  a.n., 
antennal  nerve;  m.oc,  middle  ocellus;  op.I.,  optic  lobe;  a.L,  olfactory  lobe;  a.s.g., 
anterior  sympathetic  ganglion;  p.s.g.,  posterior  sympathetic  ganglion;  f.g.,  frontal 
sympathetic  ganglion;  Ibr.,  nerve  to  labrum;  oe.c,  circumoesophageal  commissure; 
g*,  subcesophageal  ganglion;  md.,  nerve  to  mandible;  mx.,  nerve  to  maxilla;  l.n., 
nerve  to  labium;  «.,  unknown  nerve,  perhaps  salivary.  (After  Burgess;  greatly 
magnified.) 

Fig.  47. — Cross-section  of  brain,  oesophagus,  circumcesophageal  commissures,  and 
subcesophageal  ganglion  of  larva  of  the  giant  crane-fly,  Holoriisia  rubiginosa. 


nervous  system  by  commissures  which  meet  the  brain  just  at  the  origin 
from  it  of  the  circumoesophageal  commissures. 

The  specialization  of  the  ventral  nerve-chain  is  always  of  the  nature  of 
a  concentration,  and  especially  cephalization  of  its  ganglia  (Figs.  49  and 
50).  The  abdominal  ganglia  may  be  fused  into  two  or  three  or  even  into 
one  compound  ganglion;  or  indeed  all  of  them  may  migrate  forward  and 
fuse  with  the  hindmost  thoracic  ganglion,  thus  leaving  the  whole  abdomen 


24    The  Structure  and  Special  Physiology  of  Insects 


to  be  innervated  by  long  nerves  running  from  the  thorax.  The  thoracic 
gangha  may  fuse  to  form  one,  and  in  extreme  cases  all  the  abdominal  and 
thoracic  ganglia  may  be  fused  into  one  large  mid- 
thoracic  center. 

In  tracing  the  development  of  the  nervous 
system  during  the  ontogeny  of  one  of  the  special- 
ized insects,  the  changes  from  generalized  condi- 
tion, i.e.,  presence  of  numerous  distinct  ganglia 
segmentally  disposed,  shown  in  the  newly  hatched 


Fig. 


Fig 


48.  riG    49. 

Fig.  48. — Part  of  sympathetic  nervous  system  of  larva  of  harlequin-fly,  Chironomus 
dorsalis.  oes.,  oesophagus;  j.g.,  frontal  ganglion;  r.n.,  recurrent  nerve;  d.v.,  dorsal 
vessel;  n*,  nerve  passing  from  brain  to  frontal  ganglion  (Newport's  fourth  nerv-e); 
hr.,  brain;  rn.,  point  of  division  of  recurrent  nerve;  tr.,  tracheae;  pg.,  paired  ganglia; 
d.v.Ji.,  nerve  of  dorsal  vessel;  d.v.g.,  ganglia  of  dorsal  vessel;  g.n.,  gastric  nerve 
to  cardiac  chamber.  The  course  of  the  recurrent  nerve  beneath  the  dorsal  vessel  is 
dotted.     (After  Miall  and  Hammond;   greatly  magnified.) 

Fig.  49. — Stages  in  the  development  of  the  nervous  system  of  the  honey-hee,  Apis  nielli- 
fica;  I  showing  the  ventral  nerve-cord  in  the  youngest  larval  stage,  and  7  the  system 
in  the  adult.     (After  Brandt;   much  enlarged.) 

larva,  to  specialized  condition,  i.e.,  extreme  concentration  and  cephalization, 
that  is,  migration  forward  and  fusion  of  the  ganglia,  shown  in  the  adult, 
are  readily  followed  (Figs.  49  and  50). 

The  special  senses  of  insects  and  the  sense-organs  are  of  particular  inter 
est  because  of  the  marked  unusualness  of  the  character  of  the  specialization 
of  both  the  organs  and  senses,  as  compared  with  the  more  familiar  condi- 
tions of  the  corresponding  organs  and  functions  of  our  body.     The  world 
is  known  to  animals  only  by  the  impressions  made  by  it  on  the  sense-organs, 


The  Structure  and  Special  Physiology  of  Insects    25 


and  the  particular  condit'on  of  functioning  of  these  organs,  therefore,  is  of 
unique  importance  in  the  life  of  any  particular  animal.  If  the  senses  vary 
much  in  their  capacities  among  different  animals,  the  world  will  have  a  differ- 
ent seeming  to  different  creatures.  It  will  be  chiefly  known  to  any  par- 
ticular species  through  the  dominant  sense  of  that  species.  To  the  con- 
genitally  blind  the  world  is  an  experience  of  touched  things,  of  heard  things, 
and  of  smelled  and  tasted  things.  To  the  bloodhound  it  is  known  chiefly 
by  the  scent  of  things.  It  is  a  world  of  odors;  the  scent  of  anything  deter- 
mines its  dangerousness,  its  desirableness,  its  interestingness.  As  insects 
know  it,  then,  the  world  depends  largely  upon  the  particular  character  and 
capacity  of  iheir  sense-organs,  and  we  reahze  on  even  the  most  superficial 
examination  of  the  structure  of  these  organs,  and  casual  observation  of  the 


Fig.  50. — Stages  in  the  development  of  the  nervous  system  of  the  water-beetle,  ^cilins 
sulcatus;  i  showing  the  ventral  nerve-cord  in  the  earliest  larval  stage,  and  7  the 
system  in  the  adult.     (After  Brandt;    much  enlarged.) 

responses  of  insects  to  those  stimuli,  like  sound-waves,  light-waves,  dis- 
solved and  vaporized  substances,  which  affect  the  sense-organs,  that  the 
insects  have  some  remarkable  special  sense-conditions.  But  the  difficul- 
ties in  the  way  of  understanding  the  psychology  of  any  of  the  lower  animals 
are  obvious  when  it  is  recalled  that  our  only  knowledge  of  the  character 
of  sense-perceptions  has  to  depend  solely  on  our  experience  of  our  own  per- 
ceptions, and  on  the  basis  of  comparison  with  this.  We  do  not  know  if 
hearing  is  the  same  phenomenon  or  experience  with  insects  as  with  us. 
But  a  comparison  of  the  morphology  of  the  insect  sense-organs  with  that 
of  ours,  and  a  course  of  experimentation  with  the  sight,  hearing,  smelling, 
etc.,  of  insects,  based  on  similar  experimentation  with  our  own  senses,  leads 
us  to  what  we  believe  is  some  real  knowledge  of  the  special  sense-condi- 
tions of  insects. 


2  6    The  Structure  and  Special  Physiology  of  Insects 


Insects  certainly  have  the  senses  of  touch,  hearing,  taste,  smell,  and  sight. 
If  they  have  others,  v^e  do  not  knovv^  it,  and  probably  cannot,  as  we  have 

no  criteria  for  recognizing  others. 
The  tactile  sense  resides  especially 
in  so-called  "tactile hairs,"  scattered 
more  or  less  abundantly  or  regu- 
larly over  the  body.  Each  of  these 
hairs  has  at  its  base  a  ganglionic 
nerve-cell  from  which  a  fine  nerve 
runs  to  some  body  ganglion  (Fig.  51). 
They  are  specially  numerous  and 
conspicuous  on  the  antennas  or 
"  feelers,"  and  often  on  certain  pro- 
cesses called  cerci,  projecting  from 
the  tip  of  the  abdomen.  They  may 
occur,  however,  on  any  part  of  the 
body,  and  are  usually  recognizable 
by  their  length  and  semi-spinous  nature.  The  sense  of  taste  resides 
in  certain  small  papillae,  usually  two-segmented,  or  in  certain  pits,  which 


Fig.  51. — Diagram  showing  innervation  of  a 
tactile  hair,  sh.,  tactile  hair;  ch.,  chitinized 
cuticle;  hyp.,  hypoderm,  or  cellular  layer 
of  the  skin;  s.c,  ganglion  cell;  c.o.,  gan- 
glion of  the  central  nervous  system.  (After 
vom  Rath.) 


Fig.  52.  Fig.  53. 

Fig.  52. — Nerve-endings  in  tip  of  maxillary  palpus  of  Locusta  viridissima.  s.h.,  sense- 
hairs;  i'.c,  sense-cells;  6.c.,  blood-cells.     (After  vom  Rath;  greatly  magnified.) 

Fig.  53. — -Nerve-endings  in  tip  of  labial  palpus  of  Machilis  polypoda.  (After  vom 
Rath;    greatly  magnified.) 

occur  on  the  upper  wall  of  the  mouth  (epipharynx)  and  on  the  mouth- 
parts,  especially  the  tips  of  the  maxillary  and  labial  palpi,  or  mouth- 
feelers.     As  substances   to   be   tasted   have  to  be  dissolved,  and   have   to 


The  Structure  and  Special  Physiology  of  Insects    27 


come  into  actual  contact  with  the  special  taste  nerves,  it  is  obvious 
that  insects,  to  taste  solid  foods,  have  first  to  dissolve  particles  of  these 
foods  in  the  mouth-fluids,  and  that  the  taste-organs  have  to  be  situated 
in  the  mouth  or  so  that  they  can  be  brought  into  it  to  explore  the  food,  as 
are  the  movable,  feeler-like  palpi.  What  experimentation  on  the  sense  of 
taste  in  insects  has  been  carried  on  shows  that  certain  insects  certainly  taste 
food  substances,  and  indicates  that  the  sense  is  a  common  attribute  of  all 
insects.  Lubbock's  many  experiments  with  ants,  bees,  and  wasps  present 
convincing  proof  of  the  exercise  of  the  taste  sense  by  these  insects.  Forel 
mixed  morphine  and  strychnine  with  honey,  which  ants,  attracted  by  the 
honey  smell,  tasted  and  refused.  Will's  experiments  show  that  wasps 
recognize  alum  and  quinine  by  taste.  He  found  bees  and  wasps  to  have 
a  more  delicate  gustatory  sense  than  flies. 

Smell  is  probably  the  dominant  special  sense  among  insects.  It  exists 
at  least  in  a  degree  of  refinement  among  certain  forms  that  is  hardly 
equalled  elsewhere  in  the  animal  kingdom.  The  smelling  organs  are  micro- 
scopic pits  and  minute  papillte  seated  usually  and  especially  abundantly 
on  the  antennae,  but  probably  also  occurring  to 
some  extent  on  certain  of  the  mouth-parts.  The 
fact  that  the  antennae  are  the  principal,  and  in 
many  insects  the  exclusive,  seat  of  the  olfactory 
organs  has  been  proved  by  many  experiments  in 
removing  the  antennae  or  coating  them  with  par- 
affine.  Insects  thus  treated  do  not  find  food  or 
each  other.  As  substances  to  be  smelled  must, 
actually  come  into  contact,  in  finely  divided  con- 
dition, with  the  olfactory  nerve-element,  these 
pits  and  papillae  are  arranged  so  as  to  expose 
the  nerve-end  and  yet  protect  it  from  the 
ruder  contact  with  obstacles  against  which  the 
antennae  may  strike.  It  is  certain  that  most 
insects  find  their  food  by  the  sense  of  smell,  and 
the  antenna  of  a  carrion-beetle  (Fig.  54)  shows 
plainly  the  special  adaptation  to  make  this  sense 
highly  effective.  On  the  "leaves"  of  each  antenna 
of  June-beetles  nearly  40,000  olfactory  pits  occur. 
Some  of  the  results  of  experimentation  on  smell 
indicate  a  delicacy  and  specialization  of  this  sense 
hardly  conceivable.  A  few  examples  will  illustrate 
this.  It  is  believed  that  ants  find  their  way  back 
to  their  nests  by  the  sense  of  smell,  and  that 
they  can   recognize   by  scent  among   hundreds  of   individuals    taken  from 


Fig.  54. —Antenna  of  a 
carrion-bcctle  with  the 
terminal  three  segments 
enlarged  and  flattened, 
and  bearing  many  smell- 
ing-pits.  (Photomicro- 
graph by  George  O.  Mit- 
chell;   much  enlarged.) 


2  8    The  Structure  and  Special  Physiology  of  Insects 


various  communities  the  members  of  their  own  community.  Miss  Fielde's 
experiments  show  that  the  recognition  of  ants  by  each  other  depends  on  the 
existence  of  a  sense  of  smell  of  remarkable  differentiative  capacity.  The 
odors  of  the  nest,  of  the  species,  of  the  female  parent,  and  of  the  individ- 
ual are  all  distinct  and  perceivable  by  the  smelling-organs,  situated  on 
distinct  particular  antennal  segments.  In  the  insectary  at  Cornell  University 
a  few  years  ago  a  few  females  of  the  beautiful  large  promethea  moth  were 
put  into  a  covered  box  which  was  kept  inside  of  the  insectary  building. 
No  males  of  this  moth  species  had  been  seen  about  the  insectary  nor  in 

its  immediate  vicin- 
ity for  several  days, 
although  they  had 
been  specially  sought 
for  by  collectors. 
Yet  in  a  few  hours 
after  the  female 
moths  were  first  con- 
fined nearly  fifty 
male  prometheas 
were  fluttering  about 
outside  over  the  glass 
roof  of  the  insectary. 
They  could  not  see 
the  females,  but  un- 
doubtedly discovered 
them  by  the  sense  of 
smell.  These  pro- 
methea moths  have 
elaborately  branched 
or  feathered  anten- 
nae, affording  area 
for  very  many  smell- 
ing-pits. 

Mayer's  experiments  with  promethea  also  reveal  the  high  specialization 
of  the  sense  of  smell.  This  investigator  carried  450  promethea  cocoons 
from  Massachusetts  to  the  Florida  keys.  Here  on  separated  small 
islands  the  moths  issued  from  the  cocoons,  hundreds  of  miles  south  of  their 
natural  habitat.  This  isolation  insured  that  no  other  individuals  than 
those  controlled  by  the  experimenter  could  confuse  the  observations. 
Female  moths  w^re  confined  in  glass  jars  with  the  mouth  closed  by 
netting.  Other  females  were  confined  in  smaller  glass  jars  turned  upside 
down   and   the  mouth  buried   in   sand.      Males  being   released  at   various 


Fig.  55. — Auditory  organ  of  a  locust,  Melanoplus  sp.  The 
large  clear  part  in  the  center  of  the  figure  is  the  thin  tym- 
panum with  the  auditory  vesicle  (small,  black,  pear-shaped 
spot)  and  auditory  ganglion  (at  left  of  vesicle  and  connected 
with  it  by  a  nerve)  on  its  inner  surface.  (Photomicrograph 
by  George  O.  Mitchell;  greatly  magnified.) 


The  Structure  and  Special  Physiology  of  Insects    29 


distances  soon  found  their  way  to  the  jar  (containing  females)  which  had 
its  mouth  open  to  the  air,  but  no  male  came  to  the  jar  with  its  mouth  her- 
metically sealed.  Through  the  glass  sides  of  both 
jars  the  females  were  plainly  visible.  The  antenna; 
of  certain  males  were  covered  with  shellac.  These 
males,  when  released,  never  found  the  females,  and 
often  paid  no  attention  to  them  when  brought  within 
an  inch  of  their  bodies.  Of  other  males  the  eyes 
were  covered  with  pitch;  but  these  males  had  no 
difficulty  whatever  in  finding  the  females.  It  is 
plainly  obvious  from  these  experiments  that  the 
males  found  the  females  wholly  by  scent  and  not  at 
all  by  sight. 

That  some  insects  hear  is  proved  by  their  posses- 
sion of  auditory  organs,  and  has  also  been  demon-  Fig.  56.— Male  mos(|uito, 
strated   bv   experiment.      The   fact,  too,  that   manv      f  o^i"g  '^«-^'-)  antennal 

,'.   ,  .  ■'        hairs.        (After    Jordan 

msects    have    special   sound-makmg  apparatus  and      and  Kellogg;  three  times 
do   make   characteristic   sounds    is  a  kind  of   proof      natural  size.) 
that  they  can  also  hear.     The  auditory  organs  of  insects,  curiously  enough, 
are  of  several  kinds  and    are  situated  on  different  parts  of  the  body,   in 

various  species.  Among  the  locusts, 
katydids,  and  crickets,  the  most  con- 
spicuous of  all  the  sound-making  in- 
sects except  the  cicada,  the  ears  are 
small  tympanic  membranes  on  the 
base  of  the  abdomen  in  the  locusts 
(Fig.  55),  and  on  the  tibiae  of  the  fore 
legs  in  the  katydids  and  crickets. 
Associated  with  each  tympanum  is  a 
small  liquid-filled  vesicle  and  a  special 
auditory  ganglion  from  which  an 
auditory  nerve  runs  to  one  of  the 
ganglia  of  the  thorax.  Among  the 
Fig.  57.— Diagram  of  longitudinal  section  midges  and  mosquitoes  the  antennae- 
through  first  and  second  antennal  seg-  those  all-important  sensitive  Structures 

ments  of  a  mosciuito,   Mochlonyx  ciilici-  ,  ,       ,,  •  i     i        •  i 

formis,  male,   showing  complex  auditory  ~^^^   abundantly  provided   With    cer- 

organ  composed  of  fine  chitinous  rods,  tain  fine  long  hairs,  the  auditory  hairs 
nerve-fibers,     and     nerve-cells.        (After  /tt-        _/:\        u*  u    ^    i  tu     '         j 

Child;  greatly  magnified.)  ^^^S-    S6),   which   take   up    the  SOUnd- 

waves  and  transmit  the  vibrations  to  an 
elaborate  percipient  structure  composed  of  many  fine  chitin-rods  and  ganglion- 
ated  nerves  contained  in  the  next  to  basal  antennal  segment  (Fig.  57).  From 
this  segment  runs  a  principal  auditory  nerve  to  the  brain.     Many  other  insects 


30    The  Structure  and  Special  Physiology  of  Insects 


besides  the  midges  and  mosquitoes  possess  this  type  of  auditory  organ; 
in  fact  such  an  organ,  more  or  less  well  developed,  has  been  found  in  almost 
every  order  except  the  Orthoptera  (the  order  of  locusts,  crickets,  katydids, 
etc.)  in  which  the  tympanic  auditory  organs  occur. 
Special  isolated  hairs  scattered  sparsely  over  the 
body,  connected  with  a  special  peripheral  nervous 
arrangement,  are  believed  by  some  entomologists 
to  be  a  third  kind  of  auditory  structure,  and  are 
called  chordotonal  organs.  Experimentally  the 
sense  of  hearing  has  been  surely  determined  for 
certain  insects.  A  single  striking  example  of  this 
experimentation  must  here  suffice.  Mayer  fastened 
a  live  male  mosquito  to  a  glass  slide,  put  it  under 
a  microscope,  and  had  a  series  of  tuning-forks  of 
different  pitch  sounded.  When  the  Ut^  fork  of 
512  vibrations  per  second  was  sounded  many  of 
the  antennal  hairs  were  set,  sympathetically,  into 
strong  vibration.  Tuning-forks  of  pitch  an  octave 
lower  and  an  octave  higher  also  caused  more 
vibration  than  any  intermediate  notes.  The  male 
mosquito's  auditory  hairs,  then,  are  specially  fitted  to  respond  to,  i.e.,  be 
stimulated  by,  notes  of  a  pitch  produced  by  512  vibrations.  Other,  but 
fewer,  hairs  of  different  length  vibrated  in  response  to  other  tones.  Those 
auditory  hairs  are  most  affected  which  are  at  right  angles  to  the  direction 
from  which  the  sound  comes.  From  this  it  is  obvious  that,  from  the  position 
of  the  antennae  and  the  hairs,  a  sound  will  be  loudest  or  most  intense  if  it  is 
directly  in  front  of  the  head.  If  the  mosquito  is  attracted  by  sound,  it  will 
thus  be  brought  straight  head  end  on  toward  the  source  of  the  sound.     As  a 


Fig.  58. — Longitudinal  sec- 
tion through  ocellus  of  the 
honey-bee,  Apis  mellifica. 
/.,  cuticular  lens;  i.e.,  cell- 
ular layer  of  skin;  c.b., 
crystalline  layer;  r.c,  ret- 
inal cells;  o.n.,  optic 
nerve.  (After  Redikor- 
zew;  greatly  magnified.) 


Fig.  50. — OccUar  lens  of  larva  of  a  saw-fly,  Cimhex  sp.,  showing  its  continuity  with  the 
chitinized  cuticle.     (After  Redikorzew;    greatly  magnified.) 

matter  of  fact,  Mayer  found  the  female  mosquito's  song  to  correspond  nearly 
to  Ut4,  and  that  her  song  set  the  male's  auditory  hairs  into  vibration.  With 
little  doubt,  the  male  mosquitoes  find  the  females  by  their  sense  of  hearing. 

Insects  have  two  kinds  of  eyes,  simple  and  compound.  On  most 
species  both  kinds  are  found,  on  some  either  kind  alone,  and  in  a  few  no 
eyes  at  all.     Blind  insects  have  lost  the  eyes  by  degeneration.     The  most 


The  Structure  and  Special  Physiology  of  Insects    3  i 


Fig.  60. — Part  of  corneal  cuti- 


-V~V~VV3. 


primitive    living    insects,  Campodea   and  otliers,   have  eyes,  although  only 

simple  ones.  The  larva;  of  the  specialized 
insects,  i.e.,  those  with  complete  metamor- 
phosis, also  have  only  simple  eyes.  The  com- 
pound eyes  are  not  complex  or  specialized 
derivations  of  the  simple  ones,  but  are  of  in- 
dependent origin  and  of  obviously  distinct 
structural  character.  The  simple  eyes,  also 
called  ocelli  (Fig.  58),  which  usually  occur  to 
the  number  of  three  in  a  little  triangle  on 
top  of  the  head,  are  small  and  inconspicuous, 
and  consist  each  of  a  lens,  this  being  simply 
cle,  showing  facets,  of  the  ^  small  convexly  thickened  clear  part  of  the 
fl^?^^rt/.S5fp.^Photo-  chitinized  cuticle  of  the  head-wall  (Fig.  59) 
micrograph  by  George  O.  and  a  group  of  modified  skin-cells  behind  it 
Mitchell;  greatly  magnified.)     gp^.j^^y  provided  with  absorbent  pigment  and 

capable  of  acting  as  a  simple  light-sensitive  or  retinal 
surface.  The  ocellus  is  supplied  with  a  special  nerve 
from  the  brain.  The  compound  eyes  are  always 
paired  and  situated  usually  on  the  dorso-lateral  parts 
of  the  head;  they  are  usually  large  and  conspicu- 
ous, sometimes,  as  in  the  dragon-flies  and  horse- 
flies, even  forming  two-thirds  or  more  of  the  mass 
of  the  head.  Externally  each  compound  eye  pre- 
sents a  number  (which  varies  all  the  way  from  a 
score  to  thirty  thousand)  of  facets  or  microscopic 
polygonal  cuticular  windows  (Fig.  60).  These  are 
the  cornea  of  the  eye.  Behind  each  facet  is  a  dis- 
tinct and  independent  subcylindrical  eye-element  or 
ommatidium  composed  of  a  crystalline  cone  (want- 
ing in  many  insects)  enveloping  pigment  (which  pre- 
sumably excludes  all  light-rays  except  those  which 
fall  perpendicularly  or  nearly  so  to  the  corneal 
lens    of    that    particular   ommatidium),  and  a  slender  y(|lir~--OIl 

tapering  part  including  or  composed  of   the    nervous  Fig.  61.— Longitudinal 

or    retinal  element    called    rhabdom   (Fig.   61).     Each    f^tion  through  a  few 

.  •  1        1  •       r     1  facets  and  eye-elements 

of   these  ommatidia  perceives  that  bit  of   the   external    (ommatidia)    of     the 

object  which  is  directly  in  front  of  it;  i.e.,  from  which  compound    eye   of  a 

light  is  reflected  perpendicularly  to    its   corneal  facet.  "j°.   '  /^'  ^°crysulHne 

All  of  these  microscopic  images,  each  of  a  small  part  cones;  p.,  pigment;  r., 

of  the   external  object,  form  a  mosaic   of    the  whole  ^erve * ^"(ffter' ExSJ-'j 

object,    and    thus    give    the     familiar    name    mosaic  greatly  magnified.) 


32    The  Structure  and  Special  Physiology  of  Insects 

vision   to  the  particular   kind  of  seeing   accomplished    by   the    compound 
eye. 

The  character  or  degree  of  excellence  of  sight  by   the    two   kinds    of 
eyes  obviously  varies  much.      The  fixed  focus  of  the  ocelli  is  extremely  short, 


OS 


FiG.   62. 


Fig.  64. 


F!G. 


Fig.  62. — Longitudinal  sections  through  outer  part  of  eye-elements  (ommatidia)  of  com- 
pound eyes  of  Lasiocampia  quercijolia;  ommatidia  at  left  showing  disposition  of 
pigment  in  eyes  in  the  light,  at  right,  in  the  dark.     (After  Exner;   greatly  magnified.) 

Fig.  63. — Longitudinal  section  through  a  few  eye-elements  of  the  compound  eye  of  Cato- 
cola  niipta;  left  ommatidia  taken  from  an  insect  killed  in  the  dark,  right  ommatidium 
taken  from  insect  killed  in  the  light.     (After  Exner;    greatly  magnified.) 

Fig.  64. — Section  through  the  compound  eyes  of  a  male  May-fly,  showing  division  of 
each  compound  eye  into  two  parts,  an  upper  part  containing  large  eye -elements 
(ommatidia),  and  a  lower  part  containing  small  eye-elements  (ommatidia).  (.\fter 
Zimmerman;    greatly  magnified.) 


and  probably  the  range  of  vision  of  these  eyes  is  restricted  to  an  inch  or 
two  in  front  of  the  insect's  head.  Indeed  entomologists  commonly  believe 
that  the  ocelli  avail  little  beyond  distinguishing  between  hght  and  darkness. 
With  the  compound  eyes  the  focus  is  also  fixed,  but  is  longer  and  the  range 
of  vision  must  extend  to  two  or  three  yards.     It  is  obvious  that  the  larger 


The  Structure  and  Special  Physiology  of  Insects    33 

and  more  convex  the  eyes  the  wider  will  be  the  extent  of  the  visual  field, 
while  the  smaller  and  more  abundant  the  facets  the  sharper  and  more  dis- 
tinct will  be  the  image.  Although  no  change  in  focus  can  be  effected,  cer- 
tain accommodation  or  flexibility  of  the  seeing  function  is  obtained  by  the 
movements  of  the  pigment  (Figs.  62  and  63)  tending  to  regulate  the  amount 
of  light  admitted  into  the  eye  (as  shown  by  Exner),  and  by  a  difference  in  size 
and  pigmental  character  of  the  ommatidia  (Fig.  64)  composing  the  com- 
pound eyes  of  certain  insects  tending  to   make  part   of  the  eye  especially 


Fig.  65. — A  section  through  the  compound  eye,  in  late  pupal  stage,  of  a  blow-fly,  Calli- 
phora  sarracenicp.  In  the  center  is  the  brain  with  optic  lobe,  and  on  the  right-hand 
margin  are  the  many  eye-elements  (ommatidia)  in  longitudinal  section.  (Photomi- 
crograph by  George  O.  Mitchell;  greatly  magnified.) 

•t 

adapted  for  seeing  objects  in  motion  or  in  poor  light,  and  another  part  for 
seeing  in  bright  light  and  for  making  a  sharper  image  (as  shown  by  Zim- 
merman for  male  May-flies,  and  by  myself  for  certain  true  flies  (see  p.  318)). 
Our  careful  studies  of  the  structure  of  the  insect  eye,  and  the  experimentation 
which  we  have  been  able  to  carry  on,  indicate  that,  at  best,  the  sight  of 
insects  cannot  be  exact  or  of  much  range. 

The  psychology  of  insects,  that  is,  their  activities  and  behavior  as  deter- 
mined by  their  reflexes,  instincts,  and  intelligence,  is  a  subject  of  great  inter- 
est and  attractiveness,  but  obviously  one  difficult  to  study  exactly.     The 


34    The  Structure  and  Special  Physiology  of  Insects 

elaborateness  of  many  insect  instincts,  such  as  those  of  the  ants,  wasps,  and 
bees,  to  choose  examples  at  once  familiar  and  extreme  in  their  complexity, 
makes  it  very  difficult  to  analyze  the  trains  of  reactions  into  individual  ones, 
and  to  determine,  if  it  is  indeed  at  all  determinable,  the  particular  stimuli 
which  act  as  the  springs  for  these  various  reactions.  The  attitude  of  the 
modern  biologist  in  this  matter  would  be  to  keep  first  in  mind  the  theory 
of  reflexes,  to  look  keenly  for  physico-chemical  explanations  of  the  reac- 
tions, and  only  when  forced  from  this  position  by  the  impossibility  of  find- 
ing mechanical  explanations  for  the  phenomena  to  recognize  those  com- 
plex reflexes  which  we  call  instincts,  and  finally  those  acts  which  we  call 
intelligent,  or  reasonable,  and  which  are  possible  only  to  the  possessors  of 
associative  memory.  The  investigations,  mostly  recent,  which  have  been 
directed  toward  a  determination  of  the  immediate  springs  or  stimuli  of 
insect  reactions  indicate  clearly  that  many  of  these  responses,  even  some 
which  were  formerly  looked  on  as  surely  indicative  of  considerable  intelli- 
gence on  the  part  of  their  performers,  are  explicable  as  rigid  reflex  (mechan- 
ical) reactions  to  light,  gravity,  the  proximity  of  substances  of  certain 
chemical  composition,  contact  with  solid  bodies,  etc.  On  the  other  hand 
the  position  of  the  extreme  Upholders  (Bethe,  UexkuU,  and  others)  of  the 
purely  reflex  explanation  of  all  insect  behavior  will  certainly  prove  untenable. 
As  one  of  the  phases  of  insect  biology  to  which  this  book  is  particularly 
devoted  is  that  which  includes  the  study  of  habits,  activities,  or  behavior, 
we  may  dispense  with  any  special  discussion  of  instinct  in  this  introductory 
chapter.  It  is  sufficient  to  say  that  no  other  class  of  invertebrate  animals 
presents  such  an  interesting  and  instructive  psychology  as  the  insects. 


fMsmij 


CHAPTER    II 

DEVELOPMENT  AND  META- 
MORPHOSIS 


HAT  animals  are  born  or  hatch  from  eggs  in 
an  immature  condition  is  such  famihar  natural 
history  that  we  are  likely  to  overlook  the 
significance  and  consequences  of  the  fact  unless 
our  attention  is  particularly  called  to  them. 
This  condition  of  immaturity  makes  it  necessary 
that  part  of  the  free  life  of  the  organism  has 
to  be  devoted  to  growth  and  development  and 
has  to  be  undergone  in  an  imperfect  condition, 
a  condition  of  structure  and  physiology,  indeed,  which  may  be  very  different 
from  that  of  the  parents  or  of  maturity.  While  most  animals  that  are  born 
alive  re:emble  the  parents  in  most  respects,  always  excepting  that  of  size, 
many  of  those  animals  which  hatch  from  eggs  deposited  outside  the  body 
of  the  mother  issue  from  the  egg  with  few  indeed  of  the  characteristics  of  the 
parents  and  may  be  so  dissimilar  from  them  that  only  our  knowledge  of 
the  life-history  of  the  animal  enables  us  to  recognize  these  young  individuals 
as  of  the  same  species  as  the  parent.  The  butterfly  hatching  as  the  worm- 
like caterpillar,  and  the  frog  as  the  fish-like  tadpole,  are  the  classic  examples 
of  this  phenomenon.  The  mammals,  our  most  familiar  examples  of  animals 
which  give  birth  to  their  young  alive  and  free,  nourish,  for  weeks  or  months 
before  birth,  the  developing  growing  young.  But  with  egg-laying  animals 
usually  only  such  nourishment  is  furnished  the  young  as  can  be  enclosed 
as  food-yolk  within  the  egg-shell.  As  a  matter  of  fact,  some  young  which 
hatch  from  eggs,  as,  for  example,  chickens,  quail,  etc.,  hatch  in  well- 
developed  condition;  and  some  young  mammals,  nourished  by  the  mother's 
body  until  birth,  are  in  a  conspicuously  undeveloped  state,  as  a  young 
kangaroo  or  opossum.  But  nevertheless  it  is  generally  true  that  an  animal 
hatched  from  an  egg  has  still  a  larger  amount  of  development  to  undergo 
before  it  comes  to  the  stature  and  capacity  of  its  parents  than  one  which  is 

35 


36 


Development  and  Metamorphosis 


born  alive,  after  having  passed  a  considerable  time  growing  and  developing 
in  the  body  of  the  mother.  And  this  difference  in  degree  of  development  at 
birth  is  largely  due  simply  to  the  difference  in  amount  of  nourishment 
which  can  be  afforded  the  young.  The  embryo  in  the  egg  uses  up  its  food 
early  in  its  developmental  career  and  before  it  has  reached  the  stage  of 
likeness  to  its  parents.  It  issues  in  a  condition  picturing  some  far-distant 
ancestor  of  its  species,  or  more  frequently,  perhaps,  in  a  modified,  adapted 
condition,  fit  to  make  of  this  tender  unready  creature  thus  thrust  before 
its  time  into  the  struggle  for  living  an  organism  capable  of  caring  for  itself, 
although  not  yet  endowed  with  capacities  as  effective  as,  or  even  similar  to, 
those  of  the  parent. 

It  is  familiar  to  us,  then,  that  development  is  not  wholly  postnatal  or 
postembryonic ;    that  before  birth  or  hatching  a  greater  or  less  amount  of 

development,  requiring  a  longer  or  shorter 
period  of  time,  has  already  been  undergone. 
Every  animal  begins  life  as  a  simple  cell;  all 
animals  except  the  Protozoa  (the  simplest  ani- 
mals, those  whose  whole  body  for  its  whole 
life  is  but  a  single  cell)  finish  life,  if  red 
Nature  permits  them  to  come  through  myriad 
dangers  safely  to  maturity,  as  a  complex  of 
thousands  or  millions  of  cells  united  into 
great  variety  of  tissues  and  organs.  This 
great  change  from  most  simple  to  most  complex 
condition  constitutes  development:  the  actual 
increase  of  body-matter  and  extension  of 
dimensions  is  growth. 

Most  insects  hatch  from  eggs;  being  born 
alive  is  the  exceptional  experience  of  the  young 
of  but  few  kinds,  and  even  this  is  a  sort  of 
pseudo-birth.  Such  hatch  alive,  one  may  better 
say,  for  they  begin  life  in  eggs,  not  laid  out- 
side the  mother  body  to  be  sure,  but  held  in 
the  egg-duct  until  hatching-time.  With  very  few  exceptions,  young  insects 
are  not  nourished  by  the  mother  except  in  so  far  as  she  stores  a  supply  of 
yolk  around  or  by  the  side  of  each  embryo  inside  the  egg-shell.  The  form- 
ing of  the  egg  is  a  matter  which  does  not  lend  itself  readily  to  the  observa- 
tion and  study  of  amateurs,  but  is  a  phenomenon  of  unusual  interest  to 
whomever  is  privileged  to  discover  it.  The  insect  ovaries  consist  of  a  pair 
of  little  compact  groups  of  short  tapering  tubes  (Fig.  66).  In  the  anterior  or 
beginning  end  of  each  tube  is  a  microscopic  space  or  chamber  from  whose 
walls  cells  loosen  themselves  and  escape  into  the  cavity.     These  cells  become 


Fig.  66. — Ovaries  and  oviducts 
of  a  thrips.  o./.,  ovarial  tubes; 
o.d.,  oviduct;  r.s.,  seminal 
receptacle,  or  spermatheca; 
d.r.s.,  duct  of  the  seminal  re- 
ceptacle. (After  Uzel;  much 
enlarged.) 


Development  and  Metamorphosis 


37 


either  the  germinal  or  the  food  part  of  the  eggs.  There  seems  to  exist  no 
dififerentiation  among  these  cells  at  first,  but  soon  certain  ones  begin  to 
move  slowly  down  through  the  egg-tube  in  single  file,  each  becoming  sur- 
rounded and  enclosed  by  yolk,  i.e.,  reserve  foodstufi^.  This  gathering  of 
yolk  increases  the  size  of  the  forming  eggs,  so  that  they  appear  as  a  short 
string  of  beads  of  varying  size  enclosed  in  the  elastic  egg-tube.  When  of 
considerable  size  each  egg  in  the  lower  end  of  the  tube  becomes  enclosed 


.^ 


^y 


Fig.  67. — Insect  eggs  and  parts  of  eggs,  showing  micropyle.  a,  egg  of  Drosophila  cel- 
laris;  h,  upper  pole  of  egg  of  robber-fly,  Asilus  crabriformis;  c,  upper  pole  of  egg 
of  hawk-moth,  Sphinx  popiili;  d,  egg  of  head-louse,  Pediculus  capitis;  e,  egg  of 
dragon-fly,  Libellida  depressa;  /,  upper  surface  of  egg  of  harpy-moth,  Harpyia 
vinida;  g,  upper  pole  of  egg  of  Hammalicherus  cerdo;  h,  upper  pole  of  egg  of  sul- 
phur-butterfly, Colias  hyale.     (After  Leuckart;    much  enlarged.) 

in  two  envelopes,  a  membranous  inner  one  (yolk  or  vitelline  membrane)  and 
an  outer  horny  one,  the  chorion  or  egg-shell.  But  both  of  these  envelopes 
are  pierced  at  one  pole  by  a  tiny  opening,  the  micropyle  (Fig.  67),  and 
through  this  opening  the  fertilizing  spermatozoa  enter  the  egg  from  the 
seminal  receptacle  just  before  the  egg  is  extruded  from  the  body. 

The  development  of  the  embryo  within  the  egg  is  also  securely  sealed 
away  from  the  eyes  of  most  amateurs.  The  study  of  insect  embryology 
requires  a  knowledge  of  microscopic  technic,  and  facilities  for  fixing  and 


38 


Development  and  Metamorphosis 


imbedding  and  section-cutting  which  are  not  often  found  outside  the  college 
laboratory.  But  the  particularly  interesting  and  suggestive  stages  in  this 
development  may  be  outlined  and  illustrated  in  brief  space.  First,  the 
germinal  cell  near  the  center  of  the  egg  divides  repeatedly  (Fig.  68  A)  and 
the  resulting  new  cells  migrate  outward  against  the  inner  envelope  of  the 
egg  and  arrange  themselves  here  in  a  single  peripheral  layer,  called  the 
blastoderm  (Fig.  68  D,  bl).  On  what  is  going  to  be  the  ventral  side  of  the 
egg  the  cells  of  the  blastoderm  begin  to  divide  and  mass  themselves  to  form 
the  ventral  plate  (Fig.  69  C).  The  embryo  is  forming  here;  the  rest  of  the 
blastoderm  becomes  modified  and  folded  to  serve  as  a  double  membranous 
envelope  (called  amnion  and  serosa)  for  the  embryo.  Stretching  nearly  from 
pole  to  pole  as  a  narrow  streak  along  the  ventral  aspect  of  the  egg,  the 


</r. 


Fig.  68. — Early  stage  in  development  of  egg  of  water-scavenger  beetle,  Hydrophilus  sp. 
A,  first  division  of  nucleus;  B,  migration  of  cleavage-cells  outward;  C,  beginning 
of  blastoderm;  D,  blastoderm;  y.,  yolk;  dc,  cleavage-cells;  yc,  yolk-cells;  bl., 
blastoderm.     (After  Heider;    greatly  magnified.) 

developing  embryo  begins  soon  to  show  that  fundamental  structural  charac- 
teristic of  insects,  a  segmental  condition  (Fig.  6gD).  One  can  now  make 
out  the  forming  body-rings  or  segments,  and  each  soon  shows  the  beginnings 
or  rudiments  of  a  pair  of  appendages  (Fig.  6gE).  The  appendages  of  the 
head  and  thoracic  segments  continue  to  develop  and  begin  soon  to  assume 
their  definitive  character  of  antennae,  mouth-parts,  and  legs,  but  those  of  the 
abdominal  segments  never  get  farther  than  a  first  appearance  and  indeed 
soon  disappear.  In  the  mean  time  the  internal  systems  of  organs  are  grad- 
ually developing,  the  ventral  nerve-chain  first,  then  the  alimentary  canal, 
and  later  the  muscles,  tracheae,  and  the  heart.  All  the  time  the  yolk  is 
being  gradually  used  up,  fed  on,  by  the  cells  of  the  developing  and  growing 
embryo,  until  finally  comes  the  disappearance  of  all  the  stored  food,  and  the 
time  for  hatching. 


Development  and  Metamorphosis 


39 


The  eggs  have  been  laid,  because  of  the  remarkable  instinct  of  the 
mother,  in  a  situation  determined  chiefly  by  the  interests  of  the  young 
which  are  to  hatch  from  them.  The  young  of  many  kinds  of  insects  take 
very  different  food  from  that  of  the  mother — a  caterpillar  feeds  on  green 
leaves,  the  butterfly  on  flower-nectar — or  live  under  very  different  circum- 
stances— young  dragon-flies  and  May-flies  live  under  water,  the  adults  in 
the  air.  A  monarch  butterfly,  which  does  not  feed  on  leaves,  nor  has  ever 
before  produced  young,  seeks  out  a  milkweed  to  lay  its  eggs  upon.  The 
young    monarchs,    tiny   black-and-white-banded    caterpillars,    feed   on    the 


r7=?==^^ 


Fig.  69. — Early  stages  in  the  development  of  the  egg  of  saw-fly,  Hylotoma  beriheridis. 
C,  ventral  plate  removed  from  egg;  D,  ventral  plate,  showing  segmentation  of  body; 
E,  embryo,  showing  developing  appendages;  F,  same  stage,  lateral  aspect;  G,  older 
stage,  lateral  aspect,  ant.,  antenna;  nid.,  mandible;  mx.,  maxilla;  li.,  labium;  /',  P,  l^, 
legs;  sg.,  salivary  glands;  St.,  spiracles;  ab.ap.,  abdominal  appendages;  n.c,  nerve- 
centers;  a.,  anal  opening;  lb.,  labrum;  sd.,  oesophageal  invagination;  y.,  yolk; 
b.s.,  abdominal  segments;  pd.,  intestinal  invagination;  am.,  amnion;  s.,  serosa. 
(After  Graber;    greatly  magnified.) 

green  milkweed  leaf-tissue;  indeed  they  starve  to  death  if  they  cannot  have 
leaves  of  precisely  this  kind  of  plant!  The  reason  that  the  butterfly,  whose 
only  food  is  the  nectar  of  almost  any  kind  of  flower,  ranges  wide  to  find  a 
milkweed  for  its  eggs,  is  one  not  founded  on  experience  or  teaching  or  lea- 
son,  but  on  an  inherited  instinct,  which  is  as  truly  and  as  importantly  an 
attribute  of  this  particular  species  of  butterfly  as  its  characteristic  color 
pattern  or  body  structure.  And  the  female  of  the  great  flashing  strong- 
winged  dragon-fly,  queen  insect  of  the  air,  when  egg-laying  time  comes, 
feels  a  strange  irresistible  demand  to  get  these  eggs  into  water,  dropping 
them  in  from  its  airy  height,  or  swooping  down  to  touch  the  tip  of  the  abdo- 


40 


Development  and  Metamorphosis 


men  to  the  water's  surface,  there  releasing  them,  or  even  crawling  down 
some  water-plant  beneath  the  surface  and  with  arduous  labor  thrusting  the 
eggs  into  the  heart  of  this  submerged  plant-stem.  From  the  eggs  hatch 
wingless  dwarf-dragons  of  the  pond  bottom,  with  terrible  extensile,  clutch- 
ing mouth-parts  and  an  insatiable  hunger  for  living  prey. 

So  our  young  insects,  after  completing  their  embryonic  development, 
come  to  the  time  of  their  appearance  as  free  individuals  compelled  to  find 
their  own  food  and  no  longer  sheltered  by  a  firm  egg-shell  from  the  strenu- 


FiG.  70. — Series  of  stages  in  development  of  egg  of  fish-moth,  Lepisma  sp.  A,  begin- 
ning embryo;  B,  embryo  showing  segmentation;  C,  embryo  showing  appendages; 
D,  embryo  more  advanced;  E,  embryo  still  more  advanced;  F,  embryo  still  older 
and  removed  from  egg;  G,  embryo  removed  from  egg  at  time  of  readiness  to  hatch. 
y.,  yolk;  emb.,  embryo;  ser.,  serosa;  am.,  amnion;  ant.,  antenna;  lb.,  labrum; 
md.,  mandible;  mx.,  maxilla;  mx.p.,  maxillary  palpus;  //.,  labium;  H.p.,  labial 
palpus;  /'..  P,  P,  legs;  pr.,  proctodaeum,  or  intestinal  invagination;  cer.,  cerci;  mp., 
middle  posterior  process.     (After  Heymons;    greatly  magnified.) 

ous  fighting  and  hiding  of  the  open  road.  Now  these  young  insects,  depend- 
ing upon  how  far  they  have  carried  their  developmental  course  in  the  egg, 
hatch  either  almost  wholly  like  their  parents  (excepting  always  in  size),  or 
in  a  condition  fairly  resembling  the  parents,  but  lacking  all  traces  of  wings 
and  showing  other  less  conspicuous  dissimilarities,  or  finally  they  may  appear 
in  guise  wholly  unlike  that  of  their  parents,  in  such  a  condition  indeed  that 
they  would  not  be  recognized  as  insects  of  the  same  kind  as  the  parents. 
But  in  all  cases  the  young  are  certain,  if  they  live  their  allotted  days  or  weeks 


Development  and  Metamorphosis 


41 


or  months,  to  attain  finally  the  parent  structure  and  appearance.  This 
attainment  is  a  matter  of  further  development,  of  postembryonic  develop- 
ment, and  the  amount  or  degree  of  this  development  or  change  is  obviously 
determined  by  the  remoteness  or  nearness  of  the  young  at  the  time  of  hatch- 
ing to  the  adult  or  parental  condition.  The  young  of  many  of  our  most 
familiar  insects,  as  beetles,  flies,  moths  and  butterflies,  and  ants,  bees,  and 
wasps,  hatch  out  extremely  unlike  their  parents  in  appearance:  the  well- 
known  worm-like  caterpillars  of  butterflies  and  moths  are  striking  examples 
of  this  unlikeness.  The  changes  necessarily  undergone  in  the  develop- 
ment from  caterpillar  to  butterfly  are  so  great  that  there  actually  results 
a  very  considerable  degree  of  making  over,  or  metamorphosis  of  the  insect, 
and  for  convenience  of  roughly  classifying  insects  according  to  their  develop- 
ment, entomologists  have  adopted  the  terms  complete  metamorphosis, 
incomplete  metamorphosis,  and  no  metamorphosis  to  indicate  three  not 
very  sharply  distinguished  kinds  or  degrees  of  postembryonic  development. 

In  the  latter  category  are  comparatively  few  species,  because  most  insects 
have  wings,  and  no  insect  is  winged  at  birth.  But  the  members  of  the  sim- 
plest order  (Aptera)  are  all  primitively  wingless,  and  their 
young  are,  in  practically  all  particulars  except  body  size  and 
the  maturity  of  the  reproductive  glands,  like  the  adults 
(Fig.  71) ;  their  development  may  fairly  be  said  to  take  place 
without  metamorphosis.  In  addition  to  these  primitively 
simple  insects  there  are  certain  degenerate  wingless  species 
like  the  biting  bird-lice,  for  example,  whose  young  also 
reach  the  parental  stature  and  character  without  meta- 
morphosis. 

In  the  next  category,  that  of  development  with  in- 
complete metamorphosis,  are  included  two  large  orders 
of  insects  and  several  smaller  ones.  All  the  sucking-bugs  Y\ 
(order  Hemiptera)  and  all  the  locusts,  katydids,  crickets, 
and  cockroaches  (composing  the  order  Orthoptera),  as  well 
as  the  May-flies,  dragon-flies,  white  ants,  and  several  other 
small  groups  of  unfamiliar  forms,  agree  in  having  their 
young  hatched  in  a  condition  strongly  resembling  the 
parents,  although  lacking  wings,  and  in  some  cases,  particu- 
larly those  in  which  the  young  live  on  different  food  and  in  a  different  habitat 
from  the  adults,  differing  rather  markedly  in  several  superficial  characters. 
Such  is  the  case,  for  example,  with  the  dragon-flies,  whose  young  are  aquatic 
and  breathe  by  means  of  tracheal  gills,  and  are  provided  with  specially  con- 
structed seizing  and  biting  mouth-parts.  But  in  such  essential  character- 
istics as  number  of  legs,  character  of  eyes  and  antennas,  and,  usually,  char- 
acter of  mouth-parts,  the  young  and  parent  agree.     During  postembryonic 


I .  —  Young 
and  adult  of  Po- 
dura  sp.,  one  of 
the  simplest  in- 
sects, showing 
development 
without  meta- 
morphosis. 
(Much  enlarged.) 


42 


Development  and  Metamorphosis 


Fig.  72. — Developing  stages,  after  hatching,  of  a  locust,  Melanoplus  femur-ruhrumt 
a,  just  hatched,  without  wing-pads;  h,  after  first  moulting;  c,  after  second  moulting, 
showing  beginning  wing-pads;  d,  after  third  moulting;  e,  after  fourth  moulting, 
/,  adult  with  fully  developed  wings.  (After  Emerton;  younger  stages  enlarged; 
adult  stage,  natural  size.) 


Fig.  73. — Stages  in  development  of  the  wings  of  a  locust.  /.,  developing  rudiment  of 
fore  wing;  h.,  developing  rudiment  of  hind  wing;  w.,  wing-pad.  (After  Graber; 
twice  natural  size.) 


Development  and  Metamorphosis 


43 


development  the  young  have  to  develop  wings  and  make  what  other  change 
is  necessary  to  reach  the  adult  type,  but  the  life  is  continually  free  and  active 
and  the  change  is  only  a  simple  gradual  transformation  of  the  various  parts 
in  which  differences  exist.  A  common  locust  is  an  excellent  example  of 
an  insect  with  such  incomplete  metamorphosis.  Fig.  72  shows  the  develop- 
ing locust  at  different  successive  ages,  or  stages,  as  these  periods  are  called 
because  of  their  separation  from  each  other  by  the  phenomenon,  common 
to  all  insects,  of  moulting.  As  the  insect  grows  it  finds  its  increase  of  girth 
and  length  restrained  by  the  firm 
inelastic  external  chitinized  cuticle, 
or  exoskeleton.  So  at  fixed  periods 
(varying  with  the  various  species 
both  in  number  and  duration)  this 
cuticle  is  cast  or  moulted.  From 
a  median  longitudinal  rent  along 
the  dorsum  of  the  thorax  and  head, 
the  insect,  soft  and  dangerously 
helpless,  struggles  out  of  the  old 
skin,  enclosed  in  a  new  cuticle 
which,  however,  requires  some  little 
time  to  harden  and  assume  its 
proper  colors  (often  protective). 
After  each  moulting  the  young 
locust  appears  markedly  larger  and 
with  its  wing-pads  better  developed 
(Fig.  73).  But  not  until  the  final 
moulting — in  the  case  of  the  locust 
this  is  the  fifth — are  the  wings  usable  as  organs  of  flight.  So  that  there 
is  after  all  likely  to  be  a  rather  marked  difference  between  the  habits  of 
the  young  and  those  of  the  adult  of  an  insect  with  incomplete  metamor- 
phosis, that  difference  being  primarily  due  to  structural  differences.  The 
young  are  confined  to  the  ground,  and  their  locomotion  is  limited  to  walking 
or  hopping.  The  adults  can  live,  if  they  like,  a  life  in  the  air,  and  they 
have  a  means  of  locomotion  of  greatly  extended  capability. 

The  insects  with  complete  metamorphosis  are  the  beetles,  the  two- 
winged  flies,  the  butterflies  and  moths,  the  ichneumons,  gall-flies,  ants, 
bees,  and  wasps,  the  fleas,  the  ant-lions,  and  several  other  small  groups 
of  insects  with  less  familiar  names.  In  the  case  of  all  the  thousands  of 
species  in  these  groups,  the  young  when  hatched  from  the  egg  differ  very 
much  in  structure  and  appearance,  and  also  in  habits  and  general  economy, 
from  the  parents.  Familiar  examples  of  such  young  are  the  caterpillars 
and  "worms"  of  the  moths  and  butterflies,  the  grubs  of  beetles,  the  mag- 


FiG.  74. — Metamorphosis,  incomplete,  of  an 
assassin-bug  (family  Reduviidae,  order 
Hemiptera).  A,  young  just  hatching  from 
eggs;  B,  young  after  first  moulting,  showing 
beginning  wing-pads;  C,  older  stage  with 
complex  wing-pads;  D,  adult  with  fully 
developed  wings.  (One-half  larger  than 
natural  size.) 


44 


Development  and  Metamorphosis 


gots  of  the  flesh-  and  house-flies,  and  the  helpless  soft  white  grubs  in  the 
cells  of  bees  and  wasps.  These  strange  young,  so  unlike  their  parents, 
have  the  generic  name  larva?,  and  the  stage  or  life  of  the  insect  passed  as  a 
larva  is  known  as  the  larval  stage.  In  almost  all  cases  these  larvae  have 
mouth-parts  fitted  for  biting  and  chewing,  while  most  of  the  adults  have 
sucking-mouth  parts;   the  larvae  have  only  simple  eyes  and  small  inconspicu- 


FiG.  75. — Metamorphosis,  complete,  of  monarch  butterfly,  Anosia  plexippus.  a,  egg 
(greatly  magnified);  b,  caterpillar  or  larva;  c,  chrysalid  or  pupa;  d,  adult  or  imago. 
(After  Jordan  and  Kellogg.     Natural  size.) 

ous  antennae;  the  adults  have  both  simple  and  compound  eyes  and  well- 
developed  conspicuous  antennae;  the  larvae  may  have  no  legs,  or  one  pair  or 
two  or  any  number  up  to  eight  or  ten  pairs;  the  adults  have  always  three 
pairs;  the  larvae  are  wholly  wingless,  nor  do  external  wing-pads  (i.e., 
developing  wings)  appear  outside  the  body  during  the  larval  stage;  the 
adults  have  usually  two  pairs  (sometimes  one  or  none)  of  fully  developed 
wings.     Internally  the  differences  are  also  great.     The  musculation  of  the 


Development  and  Metamorphosis 


45 


Fig.  76. — Larva,  pupa,  and  adult  of 

the  flesh-fly,  Calliphora  crytJiroce- 
phala,  with  complete  metamor- 
phosis.    (Two  times  natural  size.) 


larva  is  like  that  of  a  worm,  to  accomplish  wriggling,  crawling,  worm-like 
locomotion;  in  the  adult  it  is  very  different,  particularly  in  head  and  thorax; 
the  alimentary  canal  is  usually  adapted  in  the  larva  for  manipulating  and 
digesting  solid  foods;  in  the  adult,  usually  (except  with  the  beetles  and 
a  few  other  groups),  for  liquid  food;  there  may  be  large  silk-glands  in  the 
larva,  which  are  rarely  present  in  the 
adult;  the  respiratory  system  of  the  larvae 
of  some  flies  and  Neuroptera  is  adapted 
for  breathing  under  water;  this  is  only 
rarely  true  of  the  adults.  The  heart 
and  the  nervous  system  show  lesser  dif- 
ferences, but  even  here  there  is  no  iden- 
tity :  the  ventral  nerve  chain  of  the  larvae 
may  contain  twice  as  many  distinct  gan- 
glia as  in  the  adult. 

The  larva  lives  its  particular  kind  of 
life:  it  grows  and  moults  several  times; 
but  externally  it  shows  at  no  time  any 
more  likeness  to  the  adult  than  it  did  at 
hatching.  But  after  its  last  moult  it  ap- 
pears suddenly  in  the  guise  of  a  partially 
formed  adult  in  (usually)  quiescent  mummy-like  form,  with  the  antennae, 
legs,  and  wings  of  the  adult  folded  compactly  on  the  under  side  of  the 
body,  and  the  only  sign  of  life  a  feeble  bending  of  the  hind-body  in  re- 
sponse to  the  stimulus  of  a  touch.  This  is  the  insect  of  complete  meta- 
morphosis   in    its  characteristic    second   stage  (or   third   if    the   egg    stage 

is  called  first),  the  pupal  stage.  The 
mummy  is  called  pupa  or  chrysalid.  As 
the  insect  cannot,  in  this  stage,  fight  or 
run  away  from  its  enemies,  its  defence 
lies  in  the  instinctive  care  with  which  the 
larva,  just  before  pupation,  has  spun  a 
protecting  silken  cocoon  about  itself,  or 
has  burrowed  below  the  surface  of  the 
ground,  or  has  concealed  itself  in  crack 
or  crevice.  Or  the  defence  may  lie  in  the  fine  harmonizing  of  the  color  and 
pattern  of  the  naked  exposed  chrysalid  with  the  bark  or  twig  on  which  it 
rests;  it  may  be  visible  but  indistinguishable.  The  insect  as  pupa  takes 
no  food;  but  the  insect  as  larva  has  provided  for  this.  By  its  greed  and 
overeating  it  has  laid  up  a  reserve  or  food-store  in  the  body  which  is  drawn 
on  during  the  pupal  stage  and  carries  the  insect  through  these  days  or  weeks 
or  months  of  waiting  for  the  final  change,  the  transformation  to  the  renewed 


Fig.  77. — Adult  worker  {a)  and  larva 
{b)  of  honey-bee.  (Adult  natural 
size;  larva  twice  natural  size.) 


46 


Development  and  Metamorphosis 


active  food-getting  life  of  the  adult  or  imaginal  stage.  Familiar  examples 
of  this  kind  of  metamorphosis,  the  real  metamorphosis,  are  provided  by 
the  life  of  the  monarch  butterfly,  the  honey-bee,  and  the  blow-fly.  The  great 
red-brown  monarch  lays  its  eggs  on  the  leaves  of  a  milkweed;  from  the  eggs 
hatch  in  four  days  the  tiny  tiger-caterpillars  (larvae)  (Fig.  75)  with  biting 
mouth-parts,  simple  eyes,  short  antennae,  and  eight  pairs  of  legs  on  its  elon- 
gate cylindrical  wingless  body.  The  caterpillars  bite  off  and  eat  voraciously 
bits  of  milkweed-leaf;  they  grow  rapidly,  moult  four  times,  and  at  the  end 
of  eleven  days  or  longer  hang  themselves  head  downward  from  a  stem  or 


Fig.  78. — Brood-cells  from  honey-bee  comb  showing  different  stages  in  the  metamor- 
phosis of  the  honey-bee;  worker  brood  at  top  and  three  queen-cells  below;  begin- 
ning at  right  end  of  upper  row  of  cells  and  going  to  left,  note  egg,  young  larva,  old 
larva,  pupa,  and  adult  ready  to  issue;  of  the  large  curving  queen-cells,  two  are  cut 
open  to  show  larva  within.     (After  Benton;    natural  size.) 

leaf  and  pupate,  i.e.,  moult  again,  appearing  now  not  as  caterpillars,  but  as 
the  beautiful  green  chrysalids  dotted  with  gold  and  black  spots.  The  form- 
ing antennal  legs  and  wings  of  the  adult  show  faintly  through  the  pupal 
cuticle,  but  motionless  and  mummy-like  each  chrysalid  hangs  for  about 
twelve  days,  when  through  a  rent  in  the  cuticle  issues  the  splendid  butterfly 
with  its  coiled-up  sucking  proboscis,  its  compound  eyes,  long  antennae,  its 
three  pairs  of  slender  legs  (the  foremost  pair  rudimentary),  and  its  four  great 
red-brown  wings.  The  queen  honey-bee  lays  her  eggs,  one  in  each  of  the 
scores  of  hexagonal  cells  of  the  brood-comb  (Fig.  78).  From  the  egg  there 
hatches  in  three  days  a  tiny  footless,  helpless  white  grub,  with  biting  mouth- 
parts  and  a  pair  of  tiny  simple  eyes.  The  nurses  come  and  feed  this  larva 
steadily  for  five  days;  then  put  a  mass  of  food  by  it  and  "cap"  the  cell;  the 
larva  has  grown  by  this  time  so  as  nearly  to  fill  the  cell.  It  uses  up  the 
stored  food,  and  "changes"  to  the  pupa,  with  the  incomplete  lineaments 
of  the  adult  bee.     It  takes  no  more  food,  but  lies  like  a  sleeping  prisoner 


Development  and  Metamorphosis 


47 


in  its  closed  cell  for  thirteen  days,  and  then  it  awakens  to  active  life,  gnaws 
its  way  through  the  cell-cap  and  issues  into  the  hive-space  a  definitive  honey- 
bee with  all  the  wonderful  special  structures  that  make  the  honey-bee  body 
such  an  effective  little  insectean  machine.  The  blow-fiy  (Fig.  76)  lays  a  hun- 
dred or  more  little  white  eggs  on  exposed  meat.  From  these  eggs  come  in 
twenty  or  thirty  hours  the  tiny  white  wriggling  larva:  (maggots),  footless,  eye- 
less, wingless,  nearly  headless,  with  a  single  pair  of  curious  extensile  hooks 
for  mouth-parts.  For  ten  to  fourteen  days  these  larva;  squirm  and  feed  and 
grow,  moulting  twice  in  this  time;  they  then  pupate  inside  of  the  larval 
cuticle,  which  becomes  thicker,  firmer,  and  brown,  so  as  to  enclose  the  deli- 
cate pupa  in  a  stout  protective  shell.  The  blow-fly  now  looks  like  a  small 
thick  spindle-shaped  seed  or  bean,  and  this  stage  lasts  for  twelve  or  fourteen 


knitl.    ■hm.l.       h.p.1, 
B 

Fig.  7q. — Dipterous  larvae  showing  (through  skin)  the  imaginal  discs  or  buds  of  wings, 
these  buds  being  just  inside  the  skin.  A,  larva  of  black  fly,  Simulium  sp.;  B,  anteiior 
end  of  larva  of  midge,  Chironomus  sp.;  C,  anterior  end,  cut  open,  of  larva  of  giant 
crane-fly,  Holorusia  ruhiginosa;  h.pr.,  bud  of  prothoracic  respiratory  tube;  h.pl., 
bud  of  prothoracic  leg;  h.mw.,  bud  of  mesothoracic  wing;  h.ml.,  bud  of  mesothoracic 
leg;  h.mtb.,  bud  of  metathoracic  balancer;  h.tntl.,  bud  of  metathoracic  leg.  (Much 
enlarged.) 

days.  Then  the  winged  imago,  the  buzzing  blow-fly,  as  we  best  know  it, 
breaks  its  way  out.  In  the  house-fly  the  same  kind  of  life-history,  with 
complete  metamorphosis  of  the  extremest  type,  is  completed  in  ten  days. 
Nor  do  we  realize  how  really  extreme  and  extraordinary  this  metamorpho- 
sis is  until  we  study  the  changes  which  take  place  inside  the  body,  as  well 
as  those  superficial  ones  we  have  already  noted. 

The  natural  question  occurs  to  the  thoughtful  reader:  "Is  the  meta- 
morphosis or  transformation  in  the  postembryonal  development  of  such 
insects  as  the  butterfly,  bee,  and  blow-fly  as  sudden  or  discontinuous  and 
as  radical  as  the  superficial  phenomena  indicate?  "  The  answer  is  no,  and 
yes;  the  metamorphosis  is  not  so  discontinuous  or  saltatory  and  yet  is 
even  more  radical  and  fundamental  than  the  external  changes  suggest.     To 


48 


Development  and  Metamorphosis 


take  a  single  example,  the  case  of  the  blow-fly  (admittedly  an  extreme  one), 
the  phenomena  of  internal  change  are,  put  briefly,  as  follows:  The  imaginal 
wings,  legs,  and  head-parts  begin  to  develop  as  deeply  invaginated  httle 
buds  of  the  cell-layer  of  the  larval  skin  early  in  larval  life.  This  develop- 
ment is  gradual  and  continuous  until  pupation,  when  the  wing  and  le^^  rudi- 


FiG.  80. — Stages  in  development  of  wing-buds  in  the  larva  of  the  giant  crane-fly, 
Holorusia  riibiginosa  (the  wing-buds  have  been  dissected  out  and  sectioned,  so 
as  to  show  their  intimate  anatomy).  A,  B,  C,  D,  four  stages  successively  older  ch., 
chitinized  cuticle;  hyp.,  hypoderm  or  cellular  layer  of  skin;  tr.,  trachea;  irl., 
tracheoles;  p.m.,  peritrophic  membrane;  w.,  developing  wing;  t.v.,  tracheal  branch 
indicating  position   of  future  wing-vein.     (Greatly  magnified.) 

ments  and  the  new  head  are  pulled  out  upon  the  exterior  of  the  body.  Just 
before  pupation,  when  the  larva  has  given  up  its  locomotion  and  feeding, 
the  larval  muscles,  tracheae,  salivary  glands,  alimentary  canal,  and  some  other 
tissues  begin  to  disintegrate,  and  rapidly  break  wholly  down,  so  that  in  the 
pupa  there  appear  to  be  no  internal  organs  except  the  nervous  system, 
reproductive  glands,  and  perhaps  the  heart,  but  the  whole  interior  of  the 


Development  and  Metamorphosis 


49 


.•^ 


r* 


^ 


body  is  filled  with  a  thick  fluid  in  which  float  bits  of  degenerating  larval 
tissue.  At  the  same  time  with  this  radical  histolysis  or  breaking  down  of 
tissue  a  rapid  histogenesis  or  developing  of  imaginal  parts  from  certain 
groups  of  undifferentiated  primitive  cells,  derived  probably  mostly  from 
the  larval  skin-cells,  is  going  on.  Thus  many  of  the  larval  organs  and  tissues, 
instead  of  going  over  into  the  corresponding  imaginal  ones,  wholly  disinte- 
grate and  disappear,  and  the  imaginal  parts  are  newly  and  independently 
derived.  In  connection  with  the 
breaking  down  of  the  larval  tissues 
phagocytes  or  freely  moving,  tissue- 
eating,  amoeboid  blood-cells  play  an 
important  part,  although  one  not 
yet  fully  understood.  They  are 
either  the  causal  agents  of  the 
histolysis,  or  are  assisting  agents  in 
it,  the  tissue  disintegration  beginning 
independently,  or — a  recent  sugges- 
tion— they  are  perhaps  more  truly 
to  be  looked  on  as  trophocytes, 
that  is,  carriers  of  food,  namely, 
disintegrating  tissue,  to  the  develop- 
ing centers  of  the  imaginal  parts. 
Much  investigation  remains  to  be 
done  on  this  interesting  subject 
of  histolysis  and  histogenesis  in 
insects  with  complete  metamor- 
phosis, but  enough  has  been  already  accomplished  to  show  the  basic  and 
extreme  character  of  the  transformation  from  larva  to  adult. 

If  we  ask  for  the  meaning  of  such  unusual  and  radical  changes  in  the 
development  of  insects,  we  confront  at  once  an  important  biological  prob- 
lem. Most  biologists  believe  that  in  a  large  and  general  way  the  develop- 
ment of  animals  is  a  swift  and  condensed  recapitulation  of  their  evolution; 
meaning  by  development  the  life-history  or  ontogeny  of  an  individual,  and 
by  evolution  the  ancestral  history  or  phylogeny  of  the  species.  According 
to  this  "biogenetic  law"  the  interpretation  of  the  significance  of  the  various 
stages  and  characters  assumed  by  an  animal  in  the  course  of  its  development 
from  single  fertilized  egg-cell  to  the  complex  many-celled  definitive  adult 
stage  is  simple:  These  stages  correspond  to  various  ancestral  ones  in  the 
long  genealogical  history  of  the  species.  Every  vertebrate,  for  example,  is 
at  some  period  in  its  development  more  like  a  fish  than  any  other  living 
kind  of  animal ;  it  has  gill-slits  in  its  throat,  is  tailed,  and  is  indeed  a  fish- 
like  creature.     This   is   its   particular   developmental   stage,    corresponding 


Fig.  8i. — A  cross  section  of  the  body  of  the 
pupa  of  a  honey-bee,  showing  the  body-cavity 
filled  with  disintegrated  tissues  and  phago- 
cytes, and  (at  the  bottom)  a  budding  pair 
of  legs  of  the  adult,  the  larvK  being 
wholly  legless.  Photomicrograph  by  George 
O.  Mitchell;  greatly  magnified.) 


50 


Development  and  Metamorphosis 


to  the  ancestral  fish-like  ancestors  of  all  vertebrates.  Do  then  the  larvae 
and  pupae  of  insects  with  complete  metamorphosis  represent  ancestral  stages 
in  insect  evolutionary  history?     In  some  degree  the  larval  stage  does,  but 

in  no  degree  does  the  pupal. 
Insects  are  certainly  not  de- 
scended from  an  animal  that, 
like  a  pupa,  could  neither  move 
nor  eat  and  which  had  no  in- 
ternal organs  except  a  nervous 
system,  heart,  and  rudimentary 
reproductive  glands.  Biologists 
recognize  that  the  exigencies  of  life  during  adolescence  may  profoundly 
modify  what  might  be  termed  the  normal  course  of  development.  As 
long  as  the  developing  animal  is  shielded  from  the  struggle  for  existence, 
is  provided  with  a  store  of  food  and  protected  from  enemies  by  lying  in  an 
egg-shell  or  in  the  body  of  the  mother,  it  may  pursue  fairly  steadily  its  reca- 
pitulatory course  of  development;  but  once  emerged  and  forced  to  shift  for 


Fig.  82. — A  bit  of  degenerate  muscle  from  tussock 
moth,  Hemerocampa  leucostigma.  Note  phago 
cytic  cells  attacking  muscle  at  the  margins 
(Greatly  magnified.) 


Fig.  83. — Degenerating  muscle  from  pupa  of  giant  crane-fly,  Holorusia  ruhiginosa,  show- 
ing phagocytic  cells  penetrating  and  disintegrating  the  muscle -tissue.  (Greatly 
magnified.) 


itself,  it  must  be,  at  whatever  tender  age  it  is  turned  out,  or  whatever  ancient 
ancestor  it  is  in  stage  of  simulating,  adapted  to  live  successfully  under  the 
present-day  and  immediate  conditions  of  life.  If  the  butterfly  gets  hatched 
long  before  it  has  reached  its  definitive  butterfly  stage,  and  while  it  is  in 
a  stage  roughly  corresponding  to  some  worm-like  ancestors — and  from  such 
ancestors  insects  have  undoubtedly  descended — it  must  be  fitted   to   live 


Development  and  Metamorphosis 


5' 


successfully  a  crawling,  squirming,  worm-like  life.  That  those  insects  which 
hatch  as  worm-like  larvae  do  in  fact  owe  their  wingless,  worm-like  body  con- 
dition partly  to  being  born  in  a  stage  simulating  a  worm-like  ancestor  is  proba- 


FiG.  84. — Degeneration,  without  phagocytosis,  of  salivary  glands  in  old  larva  of  giant 
crane-fly,  Holorusia  rubiginosa.  A,  cross-section  of  salivary  gland  before  degen- 
eration has  begun;  B,  cross-section  of  salivary  gland  after  degeneration  has  set  in. 
(Greatly  magnified.) 

bly  true.  But  to  be  a  successful  worm  demands  very  different  bodily  adapta- 
tions from  those  of  a  successful  butterfly.  And  so  far  does  the  larval  butterfly 
go,  or  so  far  has  it  been  carried,  in  meeting  these  demands  that  nature  finds  it 
more  economical — to  get  into  figurative  language — 
or  easier  to  break  down  almost  wholly  the  larval 
body — after  a  new  food-supply  for  further  develop- 
ment has  been  got  and  stored  away,  and  to 
build  up  from  primitive  undifferentiated  cell  begin- 
nings the  final  definitive  butterfly  body,  than  to 
make  over  these  very  unlike  larval  parts  into  the 
adult  ones.  The  pupal  stage,  quiescent,  non-food 
taking,  and  defended  by  a  thick  chitinous  wall, 
often  enclosed  in  a  silken  cocoon,  buried  in  the 
ground  or  crevice,  or  harmonizing  so  perfectly  with 
its  environment  as  to  be  indistinguishable  from  it, 
is  the  chief  period  of  this  radical  and  marvelous 
breaking  down  and  building  anew.  It  is  an  inter- 
polated stage  in  the  development  of  the  butterfly 
corresponding  to  nothing  in  the  phyletic  history; 
an  adaptation  to  meet  the  necessities  of  its  life- 
conditions.  To  my  mind,  this  is  the  interpretation  of  the  phenomena  of 
complete  metamorphosis. 


Fig.  85. — Cross-section 
of  newly  developing 
muscle  in  pupa  of 
honey-bee,  Apis  mel- 
lifica.  (Greatly  mag- 
nified.) 


CHAPTER    III 
THE   CLASSIFICATION    OF   INSECTS 

As  has  been  explained  in  the  preceding  chapter,  insects  are  primarily  classi- 
fied on  the  basis  of  their  postembryonic  development.  Insects  with  incom- 
plete metamorphosis,  that  is,  those  which  do  not  undergo  a  non-feeding, 
usually  quiescent,  pupal  stage  in  their  development  are  believed  to  be  more 
nearly  related  to  each  other  than  to  any  of  the  insects  which  undergo  a  so- 
called  complete  metamorphosis.  So  they  are  spoken  of  collectively  as  the 
Hemimetabola,  while  all  the  insects  with  a  distinct  pupal  stage  are  called 
the  Holometabola.  But  when  one  has  collected  an  adult  insect,  as  a  fly 
or  moth  or  grasshopper,  and  wishes  to  classify  it,  this  primary  classification 
based  on  character' of  development  often  cannot  be  made  for  lack  of  informa- 
tion regarding  the  life-history  of  the  particular  insect  in  hand.  The  next 
grouping  is  into  orders,  and  this  grouping  is  based  chiefly  on  structural 
characters,  and  corresponds  to  one's  already  more  or  less  familiar  knowledge 
of  insect  classification.  Thus  all  the  beetles  with  their  horny  fore  wings 
constitute  one  order,  the  Coleoptera;  the  moths  and  butterflies  with  their 
scale-covered  wings  another  order,  the  Lepidoptera;  the  two-winged  flies 
the  order  Diptera,  the  ants,  bees,  wasps,  and  four-winged  parasitic  flies 
the  order  Hymenoptera,  and  so  on.  So  that  the  first  step  in  a  beginner's 
attempt  to  classify  his  collected  insects  is  to  refer  them  to  their  proper  orders. 

Now  while  entomologists  are  mostly  agreed  with  regard  to  the  make-up 
of  the  larger  and  best  represented  orders,  that  is,  those  orders  containing 
the  more  abundant  and  familiar  insects,  there  are  certain  usually  small, 
obscure,  strangely  formed  and  more  or  less  imperfectly  known  insects  with 
regard  to  whose  ordinal  classification  the  agreement  is  not  so  uniform.  While 
some  entomologists  incline  to  look  on  them  simply  as  modified  and  aberrant 
members  of  the  various  large  and  familiar  orders,  others  prefer  to  indicate 
the  structural  differences  and  the  classific  importance  of  these  differences 
by  establishing  new  orders  for  each  of  these  small  aberrant  groups.  IVIost 
entomologists  of  the  present  incline  toward  this  latter  position,  so  that  whereas 
Linnasus,  the  first  great  classifier  of  animals,  divided  all  insects  into  but 
seven  orders,  the  principal  modern  American  *  text-book  of  systematic  ento- 

*  Comstock,  J.  H.,  A  Manual  of  Insects,  1898. 

52 


The  Classilication  of  Insects  53 

mology  recognizes  nineteen  distinct  ones.  This  does  not  mean,  of  course,  that 
twelve  new  orders  of  insects  have  been  found  since  Linnaius's  time,  although 
two  or  three  of  the  orders  are  in  fact  founded  on  insects  unknown  to  him, 
but  means  that  certain  small  groups  classified  by  Linnaeus  simply  as  famihes 
in  his  large  orders  have  been  given  the  rank  of  distinct  orders  by  modern 
systematists.  And  as  our  knowledge  of  insects  and  their  relationship  to 
each  other  is  certainly  much  larger  now  than  it  was  one  hundred  and  fifty 
years  ago,  we  may  feel  confident  that  the  many-order  system  of  classifica- 
tion is  more  nearly  a  true  expression  of  the  natural  interrelationships  of 
insects  than  was  the  old  seven-order  system.  But  not  all  entomologists 
agree  on  the  nineteen-order  system.  Few,  indeed,  still  use  the  Linnaean 
system,  but  many  believe  that  the  division  of  the  insect  class  into  nineteen 
orders  gives  too  much  importance  to  certain  very  small  groups  and  to  some 
others  which  are  not  markedly  aberrant,  and  these  entomologists  recognize 
a  lesser  number  of  orders,  varying  with  different  authors  from  nine  to  about 
a  dozen.  In  this  book  we  shall  adopt  the  nineteen-order  system  as  used 
in  Comstock's  Manual.  In  the  first  place  the  author  beheves  that  this  classi- 
fication best  represents  our  present  knowledge  of  insect  taxonomy;  in  the 
second  place  this  is  the  classification  taught  by  nearly  all  the  teachers  of 
entomology  in  America. 

To  determine  the  order  to  which  an  insect  belongs  we  make  use  of  a 
classifying  table  or  key.  In  the  Key  to  Orders  which  follows  this  para- 
graph, all  the  insect  orders  are  characterized  by  means  of  brief  statements  of 
structural  features  more  or  less  readily  recognized  by  simple  inspection  of 
the  superficies  of  the  body;  to  determine  some  of  the  conditions  a  simple 
lens  or  hand-magnifier  will  be  needed.  The  orders  are  so  arranged  in  the 
key  that  by  choosing  among  two  or  more  contrasting  statements  the  student 
may  "trace"  his  specimen  to  its  proper  order.  Inspection  of  the  Key  with 
an  attempt  or  two  at  tracing  some  familiar  insect,  as  a  house-fly,  moth,  or 
wasp  whose  order  is  already  known,  will  make  the  method  of  use  apparent. 
It  must  be  borne  in  mind  that  young  insects,  such  as  caterpillars  of  moths, 
grubs  of  beetles,  and  the  wingless  nymphs  of  locusts,  dragon-flies,  etc.,  cannot 
be  classified  by  this  key.  Indeed  the  young  stages  of  most  of  the  insects 
which  we  know  well  as  adults  are  unknown  to  us,  and  there  is,  besides,  such 
manifold  adaptive  variety  in  the  external  structure  of  those  forms  which  we 
do  know  that  no  key  for  the  classification  into  orders  of  immature  insects 
can  now  be  made. 


54  The  Classification  of  Insects 

KEY  TO   THE  ORDERS    OF   INSECTS. 
(Arranged  by  Prof.  H.  E.  Summers.) 

(For  adult  insects  only.  If  in  any  paragraph  all  the  italicized  characters  agree  with 
the  specimen  in  hand,  the  remaining  characters  need  not  be  read;  these  latter  are  for  use 
in  doubtful  cases,  or  where  the  organs  characterized  in  italics  are  rudimentary  or  absent. 
The  technical  terms  used  in  this  Key  have  all  been  defined  in  Chapter  I.) 

A.  Primitive  wingless  insects;  month-parts  well  developed,  hut  all  except  the  apices  oj  the 
mandibles  and  maxillcB  withdrawn  into  a  cavity  in  the  head;  tarsi  (feet)  always  one- 
or  two-clawed;  body  sometimes  centiped-like,  with  well-developed  abdominal  legs, 

in  this  case  tarsi  two-clawed (The  simplest  insects.)     Aptera. 

AA.  Normally  winged  insects,  wings  sometimes  rudimentary  or  absent;  mouth -parts 
not  withdrawn  into  a  cavity  in  the  head. 

B.  Month-parts,  when  developed,  with  both  mandibles  and  maxillce  fitted  for  biting; 
abdomen  broadly  joined  to  thorax;  tarsi  never  bladder-shaped;  when  mouth- 
parts  are  rudimentary,  if  the  wings  are  two,  there  are  no  halteres  (p.  303) ;  if 
the  wings  are  four  or  absent,  the  body  is  not  densely  clothed  with  scales. 
C.  Posterior  end  of  abdomen  with  a  pair  of  prominent  tmjointed  forceps-like 
appendages;   fore  wings,  when  present,  short,  veinless,  horny  or  leathery. 

(Earwigs.)     Euplexoptera. 
CC.  Posterior  end  of  abdomen  usually  without  prominent  unjointed  forceps-like 
appendages;  when  these  are  present  the  fore  wings  are  always  developed, 
veined. 

D.      Fore  wings,  when  present,  veined  and  membranous,  parchment-like  or 
leathery;   when   absent,  the  labium  (under-lip)   either  cleft   in   the 
middle,  or  the  mouth-parts  prolonged  into  a  distinct  beak. 
E.      Fore  wings,  when  present,  thicker  than  hind  wings,  somewhat 
leathery   or   parchment-like;    hind  wings   folded   several   times 
lengthwise,  like  a  fan,  in  repose;   when  wings  are  absent,  pro- 
thorax  large. 

(Locusts,  crickets,  cockroaches,  etc.)     Orthoptera. 
EE,  Fore  wings   membranous,    of   same   structure   as   hind   wings; 
hind  wings  usually  not  folded,  but  occasionally  folded  like  a  fan; 
when  wings  are  absent,  prothorax  small. 
F,      Antennce  inconspicuous. 

G.  Hind  wings  smaller  than  fore  or  absent;  posterior  end  of 

abdomen  with    two  or  three    many-jointed  filaments. 

(May -flies.)     Ephemerida. 

GG.  Hind  wings  not  smaller  than  fore;    posteiior  end  of 

abdomen  without  many-jointed  filaments. 

(Dragon-flies  and  damsel-flies.)     Odonata. 
FF.  Antennce  conspicuous. 

G.       Tarsi   less    than    five-jointed;    labium    cleft    in    the 
middle. 

H.  Wings  always  present,  although  sometimes  very 
small;  hind  wings  broader  than  fore  wings, 
folded  in  repose;  prothorax  large,  nearly  flat 
on  dorsal  surface. 

(Stone-flies.)  Plecoptera. 


The  Classification  of  Insects  ^^ 

HH.  Hind  wings,  when  present,  not  broader  than  fore 
wings,  not  jolded  in  repose;  protliorax  small, 
collar-like. 

I.  Tarsi   four-jointed;    wings,    when  present, 
equal    in    size (Termites.)     Isoptera. 

II.  Tarsi  one-  to   three-jointed. 

J.     Tarsi     one-     or     two-jointed;      ahvays 
wingless. 

(Biting  bird-lice.)     Mallophaga. 

JJ.   Tarsi  usually  three-jointed ;  occasionally 

two-jointed,  in  which  case  wings  always 

present,    fore   wings   larger   than   hind 

wings.  (Book -lice,  etc.)  Corrodentia. 

GG.   Tarsi    five-jointed,    but    with    one    joint    sometimes 

difficult    to    distinguish;     labium    usually    entire    in 

middle,    sometimes   slightly   emarginate. 

H.      Wings,  when  present,  naked  or  slightly  hairy; 

hind  wings  with  or  without  jolded  anal  space; 

in    former    case    prothorax    large    and    nearly 

flat    on    dorsal    surface;      in    wingless    forms 

mouth  prolonged  into  a  distinct  beak. 

I.  Mouth-parts  not  prolonged   into  a  distinct 
beak,  at  most  slightly  conical. 

(Dobsons,  ant-lions,  etc.)     Neuroptera. 

II.  Mouth-parts  prolonged  into  a  distinct  beak. 

(Scorpion-flies,  etc.)     Mecoptera. 
HH.  Wings,  when  present,  thickly  covered  with  hairs; 
hind  wings  usually  with  jolded  anal  space;  pro- 
thorax  small,  collar-like;  mouth  not  prolonged 
into  a  beak.         (Caddis-flies.)     Trichoptera. 
DD.  Fore  wings,  when  present,  veinless;  horny  or  leathery;  when  absent, 
labium  entire,  and  mouth-parts  not  prolonged  into  a  distinct  beak. 

(Beetles.)     Coleoptera. 
BB.  Mouth-parts,  when  developed,  more  or  less  fitted  for  sucking;    sometimes  also 
fitted  in  part  (the  mandibles)  for  biting:   in  this  case  either  (i)  base  of  abdomen 
usually  strongly  constricted,  joined  to  thorax  by  a  narrow  peduncle,  or   (2)  the 
tarsi  bladder -shaped,  without  claws;    when  mouth  is  rudimentary  either  the 
wings  are  two  and  halteres  are  present,  or  the  wings  are  four  or  none  and 
the  body  (and  wings  if  present)  are  densely  clothed  with  scales. 
C.      Prothorax  jree;    body  {and  wings  if  present)   never  densely  clothed  with 
scales;    maxillary    palpi   usually    absent;     when    present,    tarsi   bladder- 
shaped,    without   claws. 

D.       Tarsi  bladder-shaped,  without  claws;  wings  four  {sometimes  absent), 
narrow,   fringed  with  long  hairs;    maxillae  triangular,   with  palpi. 

(Thrips.)     Thysanoptera. 

DD     Tarsi  not  bladder-shaped,   usually  clawed;    wings  not  fringed  with 

long  hairs;    maxilla  {when  mouth  is  developed)  bristle-like,  without 

palpi.  (Bugs.)     Hemiptera. 

CC.  Prothorax   not   free;     maxillary    palpi    present,    sometimes    rudimentary 

and  difficult  to  see,  in  which  case  body  (and  wings  if  present)  densely 

clothed  with  scales;    tarsi  never  bladder-shaped,  usually  clawed. 


56  The  Classification  of  Insects 

D.      Mandibles  often  rudimentary,  when  present  bristle-like. 

E.  Wings  jour  {sometimes  wanting),  clothed  with  scales;  body 
covered  thickly  with  scales  or  hairs;  mouth,  when  developed,  a 
slender  sucking  proboscis,  closely  coiled  under  head. 

(Moths  and  butterflies.)  Lepidoptera. 
EE.  Wings  two  {or  wanting),  naked  or  with  scattered  hairs;  hind 
wings  in  winged  forms  represented  by  halteres;  body  either 
naked  or  with  scattering  hairs;  mouth  a  soft  or  horny  beak,  not 
coiled  under  head. 
F.    Prothorax   poorly    developed,    scarcely    visible   from   dorsal 

side (Flies.)     Diptera. 

FF.  Prothorax   well   developed,    distinctly   visible   from    dorsal 

side;   wings  never  present (Fleas.)     Siphonaptera. 

DD.  Mandibles  well  developed,   fitted  for  biting;    wings  four  {sometimes 
two  or  none),  naked  or  with  scattered  hairs. 
(Ichneumon-flies,  gall-flies,  wasps,  bees,  and  ants.)     Hymenoptera. 

After  one  has  classified  an  insect  in  its  proper  order  there  remains,  first, 
the  determination  of  the  family  (each  order  being  composed  of  from  one 
to  many  families),  then  of  the  genus  (each  family  comprising  one  to  many 
genera),  and  finally  of  the  particular  species  of  the  genus  (each  genus  includ- 
ing one  to  many  species).  This  ultimate  classification  to  species,  however, 
will  be  possible  to  the  amateur  in  comparatively  few  cases.  There  are  so 
many  species  of  insects  (about  300,000  are  known)  that  it  would  require 
many  shelves  of  books  to  contain  the  descriptions  of  them  all.  As  a  matter 
of  fact,  in  only  a  few  orders  have  the  descriptions  of  the  species  been  brought 
together  in  manuals  available  for  general  students.  For  the  most  part  the 
descriptions  are  scattered  in  scientific  journals  printed  in  various  languages 
and  wholly  inaccessible  to  the  amateur.  There  are  less  than  1000  different 
species  of  birds  in  North  America;  there  are  more  than  10,000  known 
species  of  beetles.  Now  when  one  recalls  the  size  of  the  systematic  man- 
uals of  North  American  birds,  and  realizes  that  ten  such  volumes  would 
include  only  the  insects  of  one  order,  it  is  apparent  that  complete  manuals 
of  North  American  insects  are  out  of  the  question.  Except  in  the  case  of 
the  most  familiar,  wide-spread,  and  readily  recognizable  insect  species  we 
must  content  ourselves  with  learning  the  genus,  or  the  family,  or  with  the 
more  obscure,  slightly  marked,  and  difficult  members  of  certain  large  groups, 
as  the  beetles  and  moths,  simply  the  order  of  our  insect  specimens. 

When  one  has  determined  the  order  of  an  insect  by  means  of  the  above 
key  he  should  turn  to  the  account  of  this  particular  order  in  the  book  (see 
index  for  page)  and  find  the  keys  and  aids  to  the  further  classification  of 
the  specimen  which  the  author  has  thought  could  be  used  by  the  general 
student.  Comparison  with  the  figures  and  brief  descriptions  of  particular 
species  which  are  given  in  each  order  may  enable  the  amateur  to  identify 
the  exact  species  of  some  of  his  specimens.     But  the  specific  determination 


The  Classification  of  Insects  ^J 

of  most  of  the  insects  in  an  amateur's  cabinet  (or  in  a  professional  ento- 
mologist's either,  for  that  matter)  will  have  to  be  done  by  systematic 
speciahsts  in  the  various  insect  groups.  Few  professional  entomologists 
undertake  to  classify  their  specimens  to  species  in  more  than  the  one  or 
two  orders  which  they  make  their  special  study.  Duplicate  specimens  should 
be  given  numbers  corresponding  to  those  on  specimens  kept  in  the  cabinet, 
and  be  sent  to  specialists  for  naming.  Such  specialists,  whose  names  can 
be  learned  from  any  professional  entomologist,  have  the  privilege  of  retain- 
ing for  their  own  collections  any  of  the  specimens  sent  them. 


CHAPTER   IV 
THE   SIMPLEST    INSECTS    (Order  Aptera) 


ERTAIN  household  pests  which    are 
not    moths    and   do    not    look    like 
fish,  but  which  are  com  '^^^_Jg  monly  called  "fish-moths"  (Fig.  86),  are 
our  most  familiar  repre  sentatives  of  the  order  of  "simplest  in- 

sects." The  "fish"  part  of  the  name  comes  from  the 
covering  of  minute  scales  which  gives  the  body  a  silvery 
appearance,  and  the  "moth"  part  is  derived  from  our 
habit  of  calling  most  household  insect  pests  "moths." 
Thus  we  speak  of  "buffalo-moths"  when  we  refer  to  the 
carpet-feeding  hairy  larvae  of  certain  beetles.  When  we 
say  clothes-moths  we  are  really  using  the  word  moth 
accurately,  for  in  their  adult  condition  these  pests  are 
true  moths,  although  the  injury  to  clothing  is  wholly  done 
by  the  moth  in  its  young  or  caterpillar  stage. 

Besides  the  fish-moths  other  not  unfamiliar  Aptera  are 
the  tiny  "springtails"  (Fig.  87),  which  sometimes  occur 
in  large  numbers  on  the  surface  of  pools  of  water  or  on 
snow  in  the  spring.  Others  may  be  easily  found  in  damp 
decaying  vegetable  matter,  as  discarded  straw  or  old  toadstools.  They  are 
provided  with  an  odd  little  spring  on  the  under  side  of  the  body  by  means 
of  which  they  can  leap  from  a  few  inches  to  a  foot 
or  more  into  the  air.     Hence  their  common  name. 

In  the  order  Aptera  are  included  the  simplest  of 
living  insects.  By  "simplest"  is  meant  most  primi- 
tive, most  nearly  related  to  the  ancestors  of  the  whole 
insect  class.  Also,  as  might  be  expected,  these  most 
primitive  insects  are  simplest  in  point  of  bodily  struc- 
ture; but  in  this  respect  they  are  nearly  approached 
by  simple-bodied  members  of  several  other  orders. 
These  latter  forms,  however,  have  a  simple  body- 
structure  due  to  the  degradation  or  degeneration  of  a  more  complex  type. 

58 


Fig.  86.— The  fish- 
moth,  Lepisma 
saccharina.  (After 
Howard  and  Mar- 
latt;  twice  natural 
size.) 


Fig.  87. — The  pond-sur- 
face springtail,  Smyn- 
thurus  aquations. 
(After  Schott;  much 
enlarged.) 


The  Simplest  Insects 


59 


Fig.  88.  —  Diagrammatic  figures 
showing  the  segmental  disposi- 
tion of  the  ovarial  tubes  in  three 
Apteran  genera.  A,  J  a  pyx;  B, 
Lepisma;  C,  Campodea.  (After 
Targioni-Tozzetti;  much  en- 
larged.) 


It  is  familiar  knowledge  that  animals  which  live  parasitically  on  others,  or 

which  adopt  a  very  sedentary  life,  show  a  marked   degeneration  of  body 

structure,  an  acquired  simplicity  due  to  the  loss  of  certain  parts,  such  as 

organs  of   locomotion  (wings,  legs),  and  of 

orientation  (eyes,  ears,  feelers,  etc.).     Thus 

the    parasitic    biting    bird-lice   (order   Mal- 

lophaga,  see  p.  113),  which  Uve  their  whole 

lives  through  on  the  bodies  of  birds,  feeding 

on  the  feathers,  are  all  wingless  and  of  gener- 
ally simple  superficial  structure.     They  are 

nearly  as  simple  externally  perhaps  as  the 

Aptera,  but  we   believe   that   they  are   the 

degenerate  descendants   of   winged    and    in 

other  ways  more  complexly  formed  ancestors. 
Similarly    certain    species    of    insects    in 

nearly  all  orders  have  adopted  a  life-habit 

which  renders  flight  unnecessary,  and  these 

insects  having   lost   their  wings  are  in  this 

character   simpler   than   the   winged   kinds. 

Examples  of    such    insects    are   the  worker 

ants  and  worker  termites,  many  household  insects,  as  the  bedbugs  and  fleas, 

and  many  ground-haunting  forms,  as  some 
of  the  crickets,  cockroaches,  and  beetles. 

The  Aptera,  however,  owe  their  sim- 
plicity to  genuine  primitiveness;  among  all 
living  insects  they  are  the  nearest  repre- 
sentatives of  the  insectean  ancestors.  But 
not  all  the  Aptera  are  "simplest."  That 
is,  within  the  limits  of  this  small  order  a 
considerable  complexity  or  specialization  of 
structure  is  attained,  although  all  the 
Aptera  are  primitively  wingless,  as  the 
name  of  the  order  indicates. 

These  insects  develop  "without  meta- 
morphosis"; that  is,  the  young  (Figs.  90 
and  94)  are  almost  exactly  like  the  parents 

Fig.  89.— Diagrammatic  figures  show-  except  in  size.  They  have  simply  to  grow 
ing  the  respiratory  system  in  three  larger  and  to  become  mature.  In  internal 
Apteran  genera.     A,  Machilis;   B,     ^       ^  ^1  •        1         a    .l  1 

Nicoletia;  C,  Jcipyx.    (After  Tar-  Structure   the  smipler  Aptera    show   some 
gioni-Tozzetti;  much  enlarged.)       most  interesting  conditions.    Their  internal 

systems  of  organs  have  a  segmental  character  corresponding  to  the  external 

segmentation   of   the  body.     The   ovarial   tubes,   which   are   gathered   into 


6o  The  Simplest  Insects 

two  groups  or  masses,  one  on  each  side  of  the  body,  in  all  other  insects 
(Fig.  66),  are  separate  and  arranged  segmentally  in  Japyx  (Fig.  88),  and 
less  markedly  so  in  Machilis;  the  respiratory  system  of  Machilis  (Fig.  89) 
consists  of  nine  pairs  of  distinct,  segmentally  arranged  groups  of  tracheae 
(air-tubes),  while  the  ventral  nerve-cord  has  a  ganglion  in  almost  every  seg- 
ment of  the  body.  As  insects  are  certainly  descended  from  ancestors  whose 
bodies  were  composed  of  segments  much  less  interdependent  and  coordi- 
nated than  those  of  the  average  living  insect,  those  present-day  insects  which 
have  the  body  both  externally  and  internally  most  strongly  segmented  are 
believed  to  be  the  most  generalized  or  primitive  of  living  forms.  In  addi- 
tion to  the  segmented  character  of  the  internal  organs  we  have  also  another 
strong  evidence  of  the  primitiveness  of  the  order  in  the  possession  by  several 
Aptera  of  rudimentary  but  distinct  external  pairs  of  appendages  on  the 
abdominal  segments,  appendages  undoubtedly  homologous  with  the  thoracic 
legs,  and  probably  well  developed  in  the  insect  ancestors  as  abdominal  legs 
like  those  of  the  centipeds. 

The  order  Aptera  is  composed  of  two  suborders,  which  may  be  dis- 
tinguished as  follows: 

Abdomen  elongate,  composed  of  ten  segments,  and  bearing  long  bristle-like  or 
shorter  forceps-like  appendages  at  its  tip;  no  sucker  on  ventral  side  of  first 
abdominal  segment;   antennae  many-segmented Thysanura. 

Abdomen  short  and  robust,  composed  of  six  segments,  and  usually  with  a  forked 
spring  at  tip  (usually  folded  underneath  the  body),  and  with  a  ventral  sucker 
on  first  abdominal  segment;    antennae  4-  to  8-segmented Collembola. 

Th\'Sanura. — This  suborder  includes  three  families  (a  problematical 
fourth  family  is  found  in  Europe),  as  follows: 

Body  covered  with  scales Lepismid.e 

Body  not  covered  with  scales. 

Tip  of  abdomen  with  forceps-like  appendages jAPYGiDiE. 

Tip  of  abdomen  with  slender  many-segmented  appendages Campodeid^. 

To  the  last  family  in  the  above  key  belongs  the  interesting  creature 
Catnpodea  staphylinns  (Fig.  90),  which  zoologists  regard  as  the  most  primi- 
tive living  insect.  It  is  small,  white,  flattened,  wingless,  and  so  soft-bodied 
and  delicate  that  it  can  hardly  be  picked  up  uninjured  with  the  most  deli- 
cate forceps.  It  is  about  \  inch  long  (exclusive  of  caudal  appendages),  and 
is  to  be  looked  for  under  stones  and  bits  of  wood.  I  have  found  it  in  Ger- 
many, in  New  York,  and  in  California,  which  indicates  its  wide  distribu- 
tion. Other  collectors  have  taken  it  in  Italy,  England,  and  in  the  Pyrenees. 
It  is  said  to  live  also  in  East  India.  Is  it  not  a  little  surprising  that  this 
most  primitive,  wholly  defenceless,  and  ancient  insect  should  be  able  to  live 
successfully  the  world  over  in  the  face  of,  and  presumably  in  competition 
with,  thousands  of  highly  developed  specialized  modern  insect  forms?     It 


The  Simplest  Insects 


6i 


is   a  striking  proof  that   Nature  does  not   inevitably  crush  out   all  of  her 
first  trials  in  favor  of  her  later  results! 

The  Campodeidte  contain  another 
genus,  Nicoletia  (Fig.  91),  one  species  of 
which,  A^.  iexensis,  has  been  found  in  Cali- 
fornia and  Texas,  and  which  may  be  dis- 
tinguished from  Campodea  by  its  posses- 
sion of  three  caudal  appendages  instead 
of  two  as  in  the  latter  form. 

The  Japygidae  include  but  a  single 
genus,  Japyx,  represented  in  this  country 
by  two  described  species  and  several  as  yet 
undescribed  forms  found  at  Stanford  Uni- 
versity. Japyx  siihterraneus  is  a  species 
first  found  under  stones  at  the  mouth  of 
a  small  grotto  near  the  Mammoth  Cave 
(Kentucky).  Japyx  (Fig.  92)  is  larger  Fig.  go 
than  Campodea,^being  about  one-half  inch 
long,  and  is  readily  recognized  by  its  caudal 


Young  and  adult  of  Cam- 
podea slaphylinus  (from  California), 
the  simplest  living  insect.  (Natural 
size  indicated  by  line.) 


forceps.     Like  Campodea  its  body  is  white  and  soft. 

The  Lepismidae  include  the  familiar  household  fish- 
moths  and  a  number  of  similar  forms  which  live  under 
stones  and  logs  in  soft  soil  at  the  bases  of  tree-trunks, 
under  dead  leaves  in  woods,  and  sometimes  on  the  damp 
sand  of  seashores.  Three  genera  of  this  family  occur 
in  North  America,  which  may  be  distinguished  as 
follows: 

Caudal  appendages  short;   prothorax  very  wide  and  body 

behind  it  tapering  rapidly Lepismina. 

Caudal    appendages    long;     body    elongate    and    tapering 
gradually  backward. 

Eyes  large  and  close  together Machilis. 

Eyes  small  and  far  apart Lepisma. 

Lepisma  is  best  known  by  the  species  L.  saccharina 
(Fig.  86),  which  is  the  silverfish  or  fish-moth  of  the 
house.  It  is  silvery  white,  with  a  yellowish  tinge  on 
the  antennae  and  legs,  and  is  from  one-third  to  two- 

p  V   Z  /■  c       fifths  of  an  inch  long.     The  three  long  caudal  appen- 

ensis,   from    Califor-  dages,  characteristic  of  the  genus,  are  conspicuous.     It 

ma.  (Eight  times  nat-  fg^^jg  chiefly  on  sweet  or  starchy  materials,  sometimes 

doing  much  damage  in  libraries,  where  it  attacks  the 

bindings.     It  attacks  starched  clothing,  eats  the  paste  off  the  wall-paper, 


62 


The  Simplest   Insects 


causing  it  to  loosen,  and  infests  dry  starchy  foods.  It  runs  swiftly  and 
avoids  the  light.  It  can  be  fought  by  sprinkling  fresh 
pyrethrum  powder  in  bookcases,  wardrobes,  and 
pantries.  Another  species,  L.  domestica  (Fig.  93), 
called  the  bake-house  silverfish,  is  often  common 
about  fireplaces  and  ovens,  running  over  the  hot 
metal  and  bricks  with  surprising  immunity  from  the 
effects  of  the  heat.  This  habit  has  gained  for  it  in 
England,  according  to  Marlatt,  the  name  of  "fire- 
brat."  It  can  be  distinguished  from  the  species 
saccharina  by  the  presence  of  dark  markings  on  the 

Fig.  92. — Japyx  sp.,  from  back.  Both  saccharina  and  domestica  are  common 
California.  (Five  times  jj^  England,  and  saccharina  probably  came  to  this 
natural  size.)  r  1 

country  from  there. 

Machilis  (Fig.  95)  does  not  occur  in  houses,  but  is  more  common  than 
Lepisma  outdoors.  It  is  to  be  found  under  stones,  in  the  soil  around  the 
base  of  tree-trunks,  among  dead  leaves  and  fallen  pine-needles,  and  at  least 
one  species  occurs  in  the  sand  of  sea-beaches. 


Fig.  93. 


Fig.  94. 


Fig.   93. — The   fish-moth,    Lepisma   domestica.     (After   Howard   and   Marlatt;     a   little 

larger  than  natural  size.) 
Fig.  94. — Young  and  adult  of  Lepisma  sp.,   from  California.        (Twice  natural  size.) 

CoLLEMBOLA. — The  springtails,  mostly  of  microscopic  size,  and  wholly 
unfamiliar  to  any  but  persistent  explorers  of  nature,  comprise  many  more 
species  than  the  Thysanura.  Their  most  distinctive  character  is  the  pos- 
session, by  most  of  them,  of  the  forked  spring  (Figs.  96  and  97),  by 
means   of  which   they  leap  vigorously   when    disturbed.      This    spring    is 


The  Simplest  Insects 


63 


attached  to  the  next  to  last  body  segment  or  to  the  antepenultimate  one. 
It  consists  of  a  basal  part  and  of  two  terminal  processes. 
It  is  carried  bent  forward  under  the  body,  with  the  bipartite 
tip  held  in  a  little  catch  on  the  third  abdominal  segment. 
In  some  species  the  catch  is  lacking.  The  springtails  also 
possess  a  curious  organ  on  the  ventral  aspect  of  the  first 
abdominal  segment  which  appears  to  be  a  small  projecting 
sucker  or  tube.  This  sucker  is  often  more  or  less  divided 
into  two  parts,  in  one  family  consisting  plainly  of  two 
elongate,  delicate  tubes  (Figs.  96  and  97).  The  use  of 
this  peculiar  structure  has  not  been  definitely  determined. 
Some  entomologists  think  that  it  serves  as  a  clinging  organ, 
enabhng  the  insect  to  attach  its  body  firmly  to  the  object 
upon  which  it  rests.  Others  believe  that  the  sucker  serves 
in  some  way  to  take  up  moisture,  while  still  others  be- 
lieve it  to  aid  in  respiration.  The  Collembola  as  well 
as  the  Thysanura  cannot  live  in  a  dry  atmosphere. 
This  suborder  is  divided  into  five  families,  as  follows 
(MacGillivray) : 


Fig.  95. — Machi- 
lis  sp.,  from  Cali- 
fornia. (Three 
times  natural 
size.) 


A.      Spring  wanting Aphorurid.i;. 

AA.  Spring  present. 

B.    Spring  arising   from  ventral    side  of 
antepenultimate    abdominal    segment. 

PODURID.E. 

BB.  Spring  arising  from  ventral  side  of  penultimate  abdom- 
inal  segment. 
C.      Abdomen   elongate,  cylindrical,   much  longer  than 

broad Entomobryid^. 

CC.  Abdomen  globular,  but  little  larger  than  broad. 

D.      Terminal  segment   of   antennas   long,    ringed. 

Smynthurid.e. 

DD.  Terminal  segment  of  the  antennae  short,  with 

*    a  whorl  of  hairs Papiriid^. 


Fig.  96. — The  spotted 
springtail,  Papirius 
7naci(losus,with  spring 
folded  underneath 
body.  (Natural 
length,  2  mm.) 


Of  these  five  families  the  members  of  one,  the  Aphorurida?,  in  which 
the  spring  is  wanting,  are  non-saltatorial.  In  all  of 
the  others  leaping  is  a  characteristic  habit.  The 
Smynthuridae  and  the  Papiriidae  are  represented  by 
but  one  genus  each,  viz.,  Smynthurus  and  Papirius. 
Smynthurus  hortensis  is  a  common  form  in  gardens, 
and  may  be  called  the  "garden-flea."  It  is  found 
in  the  Eastern  States  in  May  and  June  "upon  the  Fig.  97.— The  spotted 
leaves  of  young  cabbage,  turnip,  cucumber,  and  £™,^;^i|;  3%'Se3ei 
various  other  plants,  and   also  on   the  ground.     It     (Natural  length,  2  mm.) 


64 


The  Simplest  Insects 


is  dull  black,  with  head,  legs,  and  bases  of  the  antennae  rust-color."  Smyn- 
thurus  aquaticus  (Fig.  87)  often  occurs  in  great  numbers  on  the  surface  of 
pools.     The  insects  look  like  tiny  black  spots  on  the  water  surface,  but  a 

little   observation   soon  reveals  their 
lively  character. 

The  Poduridae  and  Entomobryidae 

are  represented  in  North  America  by 

twelve    and    fourteen  genera  respec- 

>^am:  tively.     Many   of    the    Podurids   are 

illf  I  f  \w\Vi||'j|iM  >^^H^       covered   with    scales    and    are   often 

mWmhJm  ,^SSsL         prettily  colored  and  patterned.     The 

scales  (Fig.  98)  are  very  minute  and 
bear  many  fine  lines  and  cross-lines, 
regularly  arranged.     On  this  account 
Fig.  98.  Fig.  99.         they  are  much  used  as  test  objects 

Fig.  98.— Scales  from  a  springtall.     (After  ^^^    microscopes,  the   quality   of    the 

Murray;    greatly  magnified.)  '■         •       ,  ,       • 

Fig.  99.-^The  snov^-fita,  Achorutes  nivicola.  lens  being  determined  by  its  capacity 
(After  Folsom;  much  enlarged.)  ^-q  reveal  their  extremely  fine  mark- 

ings. One  of  the  most  interesting  Podurids  is 
the  snow-flea,  A  chorutes  nivkola  (Fig.  99) ,  which 
gathers  in  large  numbers  on  the  surface  of  snow 
in  the  late  spring.  Comstock  says  that  the 
snow-flea  is  sometimes  a  pest  where  maple- 
sugar  is  made,  the  insects  collecting  in  large 
quantities  in  the  sap. 

An  interesting  representative  of  the  Entomo- 
bryidae is  the  house  springtail,  Lepidocyrtiis  anieri- 
canus  (Fig.  100),  said  by  Marlatt  to  be  "not 
infrequently  found  in  dweUings  in  Washington." 
It  is  about  one-tenth  of  an  inch  long,  silvery 
gray,  with  purple  or  violet  markings.  In  Europe 
also  one  species  of  springtail  is  common  in 
houses.  As  these  insects  live  on  decaying  vege- 
table matter,  they  probably  do  no  special  harm 
in  the  house.  They  especially  frequent  rather  moist  places,  and  may  often 
be  found  in  window-plant  boxes  and  conservatories. 


Fig.  100. — The  American 
springtail,  Lepidocyrtus 
americanus,  ventral  aspect, 
showing  spring  folded  un- 
derneath body.  (After 
Howard  and  Marlatt ; 
much  enlarged.) 


CHAPTER   V 

THE    MAY-FLIES  (Order  Ephemerida)  and  STONE- 
'  '         —      FLIES  (Order  Plecoptera) 

AY-FLIES,  lake-flies,  or  shad-flies,  common  names  for 
the  insects  of  the  order  Ephemerida,  are  famihar  to 
people  who  live  on  the  shores  of  lakes  or  large  rivers, 
but  are  among  the  unknown  insects  to  most  high-and- 
dry  dwellers. 

Travelling  down  the  St.  Lawrence  River  from 
Lake  Ontario  to  Quebec  one  summer,  I  had  hosts  of 
day-long  companions  in  little  May-flies  that  clung  to 
my  clothing  or  walked  totteringly  across  my  open  book.  The  summer 
residents  of  the  Thousand  Islands  get  tired  of  this  too-constant  com- 
panionship, and  look  resentfully  on  the  feeble  shad-fly  as  an  insect  pest. 
One  evening  in  August,  1897,  my  attention,  with  that  of  other  strollers  along 
the  shore  promenade  at  Lucerne,  was  called  to  a  dense,  whirling,  tossing 
haze  about  a  large  arc  light  suspended  in  front  of  the  great  Schweizerhof. 
Scores  of  thousands  of  May-flies,  just  issued  from  the  still  lake,  were  in 
violent  circling  flight  about  the  blinding  light,  while  other  thousands  were 
steadily  dropping,  dying  or  dead,  from  the  dancing  swarm  to  the  ground. 
Similar  sights  are  familiar  in  summer-time  in  this  country  about  the  lights 
of  bridges,  or  lake  piers  and  shore  roads.  This  flying  dance  is  the  most 
conspicuous  event  in  the  life  of  the  fully  developed,  winged  May-fly,  and 
indeed  makes  up  nearly  all  of  it.  With  most  species  of  May-flies  the  winged 
adult  lives  but  a  few  hours.  In  the  early  twilight  the  young  May-fly  floats 
from  the  bottom  of  the  lake  to  the  surface,  or  crawls  up  on  the  bank,  the 
skin  splits,  the  fly  comes  forth  full-fledged,  joins  its  thousands  of  issuing 
companions,  whirls  and  dances,  mates,  drops  its  masses  of  eggs  on  to  the 
the  lake's  surface,  and  soon  flutters  and  falls  after  the  eggs.  It  takes  no 
food,  and  dies  without  seeing  a  sunrise.  Sometimes  the  winds  carry  dense 
clouds  of  May-flies  inland,  and  their  bodies  are  scattered  through  the  streets 
of  lakeside  villages,  or  in  the  fields  and  woods.     Sometimes  the  great  swarms 

65 


66 


The  May-flies  and  Stone-flies 


fall  to 

lllii)»"ja 


the  water's  surface  and  there  are  swept  along  by  wind  and  wave, 
until  finally  cast  up  in  thick  winrows,  miles  long, 
on  the  lake  beach.  Millions  of  dead  May-flies 
are  thus  piled  up  on  the  shores  of  the  Great 
Lakes. 

We  call  the  May-flies  the  Ephemerida,  after 
the  Ephemerides  of  Grecian  mythology,  and  the 
name  truly  expresses  their  brief  existence — above 
water.     But  they  have  lived  for  a  year  at  least 
before  this,  or  for  two  or  even  three  years,  as 
wingless,   aquatic    creatures,   clinging   concealed 
to  the  under  side  of  stones  in  the  lake  or  stream 
bottom,  or  actively  crawling  about  after  their  food, 
which  consists  of  minute  aquatic  plants  and  animals 
or  bits  of  dead  organic  matter.      In  this  stage  their 
whole  environment,  habits,  and  general  appearance  are 
radically  different  from  those  of  the  brief  adult  life.     We 
can  only  guess,  if  our  curiosity  compels  us  to  attempt  some 
explanation,    at   the    manner  and    the    cause  of  such    a 
strange  life-history.     What  advantage  is  there  in  such  a 
specialized  condition  that  Nature  could  not  have  arrived 
at  by  less  indirect  means?    What  is  indeed  the  utility  of 
the  whole   modification?     The  quick   answer   "utility," 
which  is  to  account  for  all  such  strange  structural  and 
physiological  conditions  on  the  basis  of  useful  adapta- 
tions brought  about  by  the  slow  but    persistent   action 
of    natural    selection,    leaves    us,    confessedly,    answered 
simply  on  a  basis  of  belief.     In  hundreds  of  cases  that 
may  come  under  our  observation,   in  how  few  are   we 
really  able  to  perceive  a  reason-satisfying  course  of  adap- 
tive development  based  on  the  selection  of  useful   small 
fluctuating  variations? 

The  eggs  of  the  May-fly  fall   from  the  body  of  the 

mother  to   the   water's   surface    in   two   packets,  which, 

If  however,  break  up    while    sinking,   so  that  the  released 


Fig.   ioi. — May-flies  about  an  electric  lamp. 


The  May-flies  and  Stone-flies 


67 


eggs  reach  the  bottom  separately.  From  each  egg  hatches  soon  a  thiy 
flattened,  soft-bodied,  six-legged  creature  called  a  nymph,  without  wings 
or  wing-pads,  and  looking  very  much  like  a  Campodea  (the  simplest 
living  insect,  see  p.  61).  This  nymph  crawls  about,  feeds,  grows,  moults, 
grows,  moults  again  and  again  (in  a  species  observed  by  Lubbock  there 
were  twenty-one  moultings),  and  finally  at  the  end  of  a  year,  or  of  two  or 
three  years,  depending  on  the  species,  is  ready  to  issue  as  a  winged  adult. 
During  the  nymphal  life  wings  have  been  slowly  developing,  visible  as 
short  pads  projecting  from  the  dorsal  margins  of  the  meso-  and  meta-thorax, 
and  appearing  visibly  larger  after  each  moulting  (Fig.  102).  Respiration  is 
accomplished  by  flat,  leaf-like  gills  (Fig.  102)  (these  do  not  appear  in  some 
species  until  after  one  or  two  moultings),  arranged  segmentally  along  the 
sides  of  the  abdomen.  The  mouth-parts  are  well  developed  for  biting 
and  chewing,  with  sharp-pointed  jaws  (mandibles).  During  its  aquatic 
life  at  the  bottom  of  stream  or  pond  the  May- 
fly has  to  undergo  all  the  vicissitudes  of  an 
exposed  and  protracted  life;  it  is  eagerly  sought 
after  by  larger,  fierce,  predaceous  insects, 
stronger  of  jaw  and  swifter  than  itself;  it  is 
the  prized  food  of  many  kinds  of  fishes,  and  it 
has  to  struggle  with  its  own  kind  for  food  and 
place. 

At  the  end  of  the  immature  life  the  nymphs 
rise  to  the  surface,  and  after  floating  there  a 
short  time  suddenly  split  open  the  cuticle  along 
the  back  and  after  hardly  a  second's  pause 
expand  the  delicate  wings  and  fly  away.  Some 
nymphs  brought  into  the  laboratory  from  a 
watering- trough  at  Stanford  University  emerged 
one  after  another  from  the  aquarivim  with 
amazing  quickness.  Almost  all  other  insects 
require  some  little  time  after  the  final  moulting 
for  the  gradual  unfolding  of  the  wings,  and  dry- 
ing and  strengthening  of  the  body-wall,  before 
flight  or  other  locomotion.  Most  of  the  May- 
fly species  go  through  another  moulting  after 
acquiring  wings,  a  phenomenon  not  known  to  occur  in  the  case  of  any  other 
insect.  The  stage  between  the  first  issuance  from  the  water  with  expanded 
wings  and  the  final  moulting  is  called  the  subimago  stage,  and  may  last, 
in  various  species,  from  but  a  few  minutes  to  twenty-four  hours.  Such 
is,  in  general,  the  life-history  of  the  May-flies.  As  a  matter  of  fact,  the 
life-history  of   no  single  May-fly  species  has  yet  been  followed  completely 


Fig.  102. — Young  (nymph)  of 
May-fly,  showing  (g)  tracheal 
gills.  (After  Jenkins  and 
Kellogg;  three  times  nat- 
ural size.) 


68 


The  May-flies  and  Stone-flies 


through.  And  here  is  an  opportunity  for  some  keen-eyed  amateur  ento- 
mologist to  add  needed  facts  to  our  knowledge  of  insect  life. 

The  breathing-organs  of  the  nymph  are  of  interest,  as  special  adaptations 
to  enable  them  to  take  up  oxygen  and  give  off  carbon  dioxide  without  com- 
ing to  the  surface,  as  do  the  water-beetles,  water-bugs,  mosquito-wrigglers, 
and  many  other  familiar  aquatic  insects.  Each  plate-like  gill  (Fig.  102) 
is  a  flattened  sac,  with  upper  and  lower  membranous  walls  which  run  into 
each   other   all   around   the   free   margin.     Inside   this   sac   is   an   air-tube 

,  (tracheal  trunk)  with  numer- 
ous fine  branches.  By  osmosis 
an  interchange  of  gases  takes 
place  through  the  walls  of  the 
tracheae  and  of  the  sac — car- 
bonic dioxide  passing  out,  and 
air  from  that  held  in  solution 
in  the  water  passing  in.  If  a 
nymph  held  in  a  watch-glass 
of  water  be  watched,  at  times 
all  the  gills  will  be  seen  rap- 
idly vibrating,  thus  setting 
up  currents  and  bringing  fresh 
aerated  water  to  bathe  the 
gills. 

In  the  adult  wihged  stage 
(Fig.  103)  the  May-flies  are 
extremely  frail  and  delicate- 
bodied.  The  wings  are  fine 
and  gauzy,  consisting  of 
the  thinnest  of  membranes 
stretched  over  a  perfect  net- 
FiG.  103. — May-fly,  from  California.     (Natural  size.)    ^ork     of     veins        The     fore 

wings  are  always  markedly  larger  than  the  hind  wings;  in  some  species 
the  latter  are  very  small  indeed,  or  even  wanting  altogether  (Fig.  104). 
The  body-wall  is  weakly  chitinized,  and  collected  specimens  almost  always 
shrivel  and  collapse  badly  in  drying.  The  abdomen  usually  bears  two 
or  three  long  filaments  on  its  tip;  the  head  is  provided  with  compound  eyes 
and  short  awl-like  antennte.  The  often-repeated  statement  in  text-books 
that  adult  May-flies  have  no  mouth  nor  mouth-parts  is  not  literally  true 
of  all  species,  as  weakly  developed  jaws  and  lips  are  present  in  some.  But 
they  are  in  such  weak  and  atrophied  condition  that  they  can  hardly  be  func- 
tional. It  is  probable,  therefore,  that  no  adult  May-fly  takes  food.  In 
the  males  of   some   species  the  compound  eyes  present  a  very  interesting 


The  May-flies  and  Stone-flies 


69 


condition,  being  divided,  each  into  two  parts,  by  a  narrow  impressed  line 
or  by  a  broader  space  (Fig.  105).  The  two  parts  differ  in  the  size  of  the 
facets  of  the  ommatidia,  i.e.,  eye-elements,  and  it  has  been  ascertained  (Zim- 
merman, 1897)  tl^^t  this  difference  in  size  of  facets 
is  accompanied  by  other  and  more  important 
structural  differences,  which  make  it  certain  that 
the  two  parts  of  the  eye  have  different  powers  of 
seeing.  One  part  is  especially  adapted  for  seeing 
in  the  dark,  or  for  detecting  slight  differences  in 
intensity  of  light,  but  is  ill-fitted  for  exact  sight, 
while  the  other  part  is  adapted  for  seeing  in 
daylight,  and  for  making  a  more  exact  picture  of 
outhne.  As  the  mating  flights  occur  usually  at 
twilight  or  in  the  evening,  Zimmerman  believes 
that  this  modification  of  the  eyes  of  the  males 
is  to  enable  them  to  discover  the  females  in  the 
whirling  shadow-dances.  Chun  has  recorded  a 
similar  division  and  difference  in  the  eye  of 
certain  ocean   crustaceans  and   believes  that  the 

"dark   eyes"    are   used   for  seeing   in  the  dimly  Fig.    104.— May-fly,    Canis 
,.   1  ,     ,  ,    ,         ,,  r  1-1       ,       /,,.   1  dimidiata,  possessing    only 

hghted  water  below  the  surface,  while  the     light  p        - 


one  pair  of  wings. 
enlarged.) 


(Much 


eyes"  are  for  special  use  at  the  brilliantly  lighted 
surface.  I  have  noted  similar  conditions  in  the  eyes  of  both  male  and 
female  net-winged  midges  (Blepharoceridae),  small,  two-winged  flies  of 
particularly  interesting  hfe  (see  p.  319).  It  is  unusual  to  find  such  parallel 
adaptations  in  forms  so  unrelated. 

The  May-flies  show  an  anatomical  condition  of  much  interest  to  ento- 
mologists in  the  paired  openings  for 
the  issuance  of  the  eggs.  Insects  have 
their  organs  arranged  in  pairs,  one  on 
each   side  of  the  middle  line  of   the 

f^^^T^  ///^  ' — ^"^^K  ■  ^'^^^  body,  as  the  legs,  wings,  mouth-parts, 
%^>^^^^'^^^^—^^^M^M  antennae,  eyes,  spiracles,  etc.,  or  exact- 
^'^  ^"^W^        \y  Qj^  ^]^g  middle  line,  as   the  heart, 

alimentary  canal,  and  ventral  nerve- 
cord.  That  is,  the  typical  insect  body 
is  bilaterally  symmetrical,  and  the 
more  apparent  this  symmetry  is  the  sim- 
pler and  more  generalized  the  insect 
is  believed  to  be.  All  other  insects  but  the  May-flies  have  the  two  egg- 
ducts,  one  from  each  egg-gland,  fused  inside  the  body,  so  as  to  form  a  short, 
single,  common  duct  on  the  median  line.     But  the  May-flies  have  the  ducts 


FiL..  105. — Section  through  head  of 
male  May-fly,  Potamanihus  hriinneus, 
showing  composition  of  compound 
eye  and  two  sizes  of  eye-elements 
(ommatidia).  (After  Zimmer;  greatly 
magnified.) 


70  The  May-flies  and  Stone-flies 

separate;  that  is,  paired  and  bilateral  for  their  whole  course.  This  is  taken 
to  be  an  indication  of  the  primitiveness  and  antiquity  of  the  order. 

If  the  May-fiies  are  an  ancient  group  of  insects,  and  there  is  httle  doubt 
of  this,  we  have  in  them  another  example  (we  have  previously  noted  one 
in  the  case  of  Campodea,  see  p.  60)  of  primitive  insects  of  excessively 
frail  and  defenceless  character  persisting  in  the  face  of  the  strenuous  struggle 
for  existence  and  of  the  competition,  in  this  struggle,  of  highly  developed, 
specialized  insect  forms.  Perhaps  the  solution  of  this  problem  in  the  case 
of  the  May-flies  is  to  be  found  in  their  extreme  prolificness  and  in  the 
ephemeral  character  of  their  adult  hves.  It  is  only  in  the  adult  condition 
that  May-flies  are  so  ill-fitted  to  defend  themselves;  so  they  simply  make  no 
attempt  to  do  so.  They  lay  their  eggs  immediately  on  coming  of  age,  and 
thus  accomphsh  the  purpose  of  their  adult  stage.  In  their  immature  form 
they  are  not  so  handicapped  in  the  struggle  for  existence,  although  they 
seem  by  no  means  in  position  to  compete  with  some  of  their  neighbors,  like 
the  nymphs  of  the  stone-fly  and  dragon-fly. 

About  300  species  of  Ephemerida  are  known,  of  which  85  occur  in 
North  America.  Their  classification  has  been  comparatively  httle  studied 
and  is  a  difficult  matter  for  beginners.  The  differences  among  the  adults 
are  so  slight,  and  the  preserved  specimens  are  so  uniformly  misshapen 
and  dried  up,  that  most  of  us  will  have  to  be  satisfied  with  knowing  that 
we  have  in  hand  a  May-fly,  without  being  able  to  assign  it  to  its  genus. 
Keys  to  the  North  American  tribes  and  genera  of  May-flies  may  be  found 
by  the  student  who  may  wish  to  attempt  the  generic  determination  of  his 
specimens,  in  a  paper  by  Banks  in  the  Transactions  of  the  American  Ento- 
mological Society,  v.  26,  1894,  pp.  239-259. 

There  are  better  defined  differences  among  the  nymphs  than  among 
the  adults,  but  unfortunately  the  nymphs  have  been  as  yet  too  little  studied 
for  the  making  out  of  a  comprehensive  key  to  the  genera.  Needham  and 
Betten  give  an  analytical  table  of  genera  of  Ephemerid  nymphs  as  far  as 
known  in  the  Eastern  United  States,  in  Bulletin  47  of  the  New  York  State 
Museum,  1901. 

On  the  under  side  of  the  same  stones  in  the  brook  "riffles"  where 
the  May-fly  nymphs  may  be  found,  one  can  almost  certainly  find  the  very 
similar  nymphs  (Fig.  106)  of  the  stone-flies,  an  order  of  insects  called 
Plecoptera.  More  flattened  and  usually  darker,  or  tiger-striped  with  black 
and  white,  the  stone-fly  nymphs  live  side  by  side  with  the  young  May-flies. 
But  they  are  only  to  be  certainly  distinguished  from  them  by  careful  exam- 
ination. The  gills  of  the  immature  stone-flies  usually  consist  of  single  short 
filaments  or  tufts  of  short  filaments  rising  from  the  thoracic  segments,  one 
tuft  just  behind  each  leg  (Fig.  106),  and  not  flat  plates  attached  to  the  sides 


The  May-flies  and  Stone-flies 


71 


of  the  abdomen  as  in  the  IVIay-fly  nymphs.  The  feet  of  the  stone-flies  have 
two  claws,  while  those  of  the  young  May-flies  have  but  one.  The  stone-fly 
nymph  has  a  pair  of  large  compound  eyes,  as  well  as  three  small  simple  eyes, 
strong  jaws  for  biting  and  chewing  (perhaps  for 
chewing  heir  nearest  neighbors,  the  soft-bodied, 
smaller  May-fly  nymphs!),  and  two  slender  back- 
ward-projecting processes  on  the  tip  of  the  abdomen. 
The  legs  are  usually  fringed  with  hairs,  which  makes 
them  good  swimming  as  well  as  running  organs. 
The  nymphs  can  run  swiftly,  and  quickly  conceal 
themselves  when  disturbed. 

All  stone-fly  nymphs,  as  far  as  known,  require 
well  aerated  water;  they  cannot  live  in  stagnant 
pools  or  foul  streams.  Needham  says  that  a  large 
number  of  the  smaller  species  are  wholly  destitute 
of  gills  absorbing  the  air  directly  through  the  skin. 
Nymphs  brought  in  from  a  brook  and  placed  in  a  Fig  106.— Young(nymph) 
;     f      .,,  .,,   ,  -11  ,-r-       1         01  stone-flv,  from  Cali- 

vessel  of  still  water  will  be  seen  with  claws  arnxed,      fornia.    (Twice  natural 

vigorously  swinging  the  body  up  and  down,  trying  size.) 
to  get  a  breath  under  the  difficult  conditions  into  which  they  have  been 
brought.  The  food-habits  are  not  at  all  well  known:  some  entomologists 
assert  that  small  May-fly  nymphs  and  other  soft-bodied  aquatic  creatures 
are  eaten,  while  others  say  that  the  food  consists  of  decaying  organic  matter. 
Here  is  another  opportunity  for  some  exact  observation 
by  the  interested  amateur.  On  the  other  hand  it  is  per- 
fectly certain  that  the  nymphs  themselves  serve  as  food 
for  fishes. 

The  fully  worked-out  life-history  of  no  stone-fly  seems 
to  have  been  recorded.  The  eggs,  of  which  5000  or  6000 
may  be  deposited  by  a  single  female,  are  probably  dropped 
on  the  surface  of  the  water,  and  sink  to  the  bottom 
after  being,  however,  weU  distributed  by  the  swift  current. 
Sometimes  the  eggs  are  carried  about  for  a  while  by  the 
female,  enclosed  in  a  capsule  attached  to  the  abdomen. 
The  young  moult  several  times  in  their  growth,  but 
probably  not  nearly  as  many  times  as  is  common  among 
May-flies.     When  ready  for  the  final  moulting,  the  nymph 


Fig.  107.  —  Exuvia 
of  nymph  of  stone 


fly.  (Natural  size.)  crawls  out  on  a  rock  or  on  a  tree-root  or  trunk  on  the 
bank,  and  splitting  its  cuticle  along  the  back,  issues  as  a  winged  adult. 
The  cast  exuviae  (Fig.  107)  are  common  objects  along  swift  brooks. 

The  adults  (Fig.  108)  vary  much  in  size  and  color,  the  smallest  being 
less  than  one-fifth  of  an  inch  long,  while  the  largest  reach  a  length  of  two 


72  The  May-flies  and  Stone-flies 

inches.  Some  are  pale  green,  some  grayish,  others  brownish  to  black. 
There  are  four  rather  large  membranous,  many-veined  wings  without  pattern, 
the  hind  wings  being  larger  than  the  front  ones.  When  at  rest,  the  fore 
wings  He  flat  on  the  back,  covering  the  much-folded  hind  wings.  The  mouth- 
parts  are  present  and  are  fitted  for  biting,  although  the  food-habits  are  not 
known.  It  is  asserted  that  some  species  take  no  food.  The  antennae  are 
long  and  slender.  The  abdomen  usually  bears  a  pair  of  long,  many-seg- 
mented, terminal  filaments.  The  body  is  rather  broad  and  flattened,  and 
there  is  no  constriction  between  the  thorax  and  abdomen.  On  the  ventral 
aspect  of  each  thoracic  segment  there  is  a  pair  of  small  openings  whose  func- 


FiG.  io8. — A  stone-fly,  Perla  sp.,  common  about  brooks  in  California.     (After  Jenkins 
and  Kellogg;    twice  natural  size.) 

tion  is  unknown.  The  adults  of  certain  species  retain,  although  in  shriveled 
and  probably  functionless  condition,  the  filamentous  gills.  This  fact  is  of 
importance  in  connection  with  the  question  as  to  whether  insects  are 
descended  from  aquatic  or  terrestrial  ancestors.  Those  who  believe  in 
the  aquatic  ancestry  have  found  a  simple  origin  for  the  spiracles  (breathing- 
pores)  by  imagining  them  to  be  the  openings  left  when  the  gills,  used  in 
aquatic  life,  were  lost.  But  the  adult  stone-flies  which  retain  their  gills 
also  have  wholly  independent  spiracles. 

About   ICO   species  of  stone-flies  are  known  in  North   America.     The 
adults  are    to  be  found  flying   over    or    near   streams,    though  sometimes 


The  May-flies  and  Stone-flies 


73 


straying  far  away.  They  rest  on  trees  and  bushes  along  the  banks.  The 
green  ones  usually  keep  to  the  green  foliage,  while  the  dark  ones  perch  on 
the  trunk  and  branches.  The  various  species  are  included  in  ten  genera, 
which  may  be  determined  by  the  following  table: 


T.\BLE   OF   NORTH   AMERICAN   GENERA   OF   PLECOPTERA. 

The  following  technical  terms  not  heretofore  defined  are  used  in  this  key:  cerci, 
slender  processes  projecting  from  the  tip  of  the  abdomen;  radial  sector,  cubital  vein, 
and  other  names  of  veins  in  the  wings  may  be  understood  by  reference  to  Fig.  109. 


S 

Fig.  109. — Diagram  of  venation  of  wing  of  a  stone-fly;  /,  costal  vein;  2,  subcostal  vein; 
3,  radial  vein;  4,  medial  vein;  5,  first  anal  vein;  6,  radial  sector,  P,  pterostigma; 
A,  arculus:  Op  a^,  a^,  apical  cells.  Between  the  medial  and  first  anal  vein  is  the 
cubital  vein,  not  numbered.  Cell  M  is  the  cell  behind  the  medial  vein;  cell  Sc  is  the 
cell  behind  the  subcostal  vein. 

A.      With  two  long,   many-jointed  cerci. 

B.      Radial  sector  not  reduced,  i.e.,  with  four  or  more  branches. 

C.  Wings  strengthened  throughout  by  many  cross-veins,  there  being  many 
cross-veins  between  the  branches  of  the  media,  between  the  accessory 
cubital  veins,  and  in  the  anal  areas  of  both  pairs  of  wings.  .Pteronarcys. 
CC.  Wings  with  few  or  no  cross-veins  between  the  branches  of  the  media, 
between  the  branches  of  the  cubital  veins,  and  in  the  anal  area. 
D.      Radial  area  of  the  fore  wings  with  an  irregular  network  of  veins- 

DiCTYOPTERYX. 

DD.  Radial  area  of  the  fore  wing  with  no  cross-veins  except  the  radial 
cross-veins,  or  with  a  few  regular  cross-veins. ..  .Perla  (in  part). 
BB.  Radial  sector  reduced,  i.e.,  with  less  than  four  branches. 
C.      Hind  wings  much  broader  than  the  fore  wings. 

D.       With  several  cross-veins  in  cell  M  of  the  fore  wings. 

E.      Cell  Sc  of  the  fore  wings  with  at  least  three  cross-veins. 

F.      With  three  ocelli Perla  (in  part). 

FF.  With  only  two  ocelli Pseudoperla. 

EE.  Cell  Sc  of  the  fore  wings  with  only  one  or  two  cross-veins. 

Small  species  of  a  green  or  yellow  color Chloroperla. 

DD,  With  only  one  cross-vein  in  cell  AI  of  the  fore  wings  between  the 

arculus  and  the  medio-cubital  cross-vein Capnia. 

CC.  Hind  wings  of  the  same  width  as  the  fore  wings;    the  anal  area  of  the 

hind  wings  not  expanded Isopteryx. 

AA.  With  the  cerci  rudimentary  or  wanting. 

B.      Second  segment  of  the  tarsi  equal  in  length  to  the  others;    rudimentary  cerci 
present T.eniopteryx. 


74  The  May-flies  and  Stone-flies 

BB.  Second  segment  of  the  tarsi  small,  shorter  than  the  others,  cerci  absent. 

C.      Veins  radiating  from  the  ends  of  the  radial  cross-vein  forming  an  X. 

Nemoura. 
CC.  Veins  radiating  from  the  ends  of  the  radial  cross-vein  not  forming  an  X. 

Leuctra. 

The  genus  Perla  (Fig.  io8)  includes  more  species  than  any  other.  The 
species  of  Pteronarcys  retain  gills  in  the  adult  condition.  The  species  of 
Chloroperla  are  small,  delicate,  and  pale  green.  Leuctra  includes  the  slender- 
est of  the  stone-flies;  they  are  small  and  brownish.  Comstock  says  that 
there  are  several  species  of  stone-flies  that  appear  on  the  snow  on  warm 
days  in  late  winter.  They  become  more  numerous  in  early  spring,  and 
often  find  their  way  into  houses.  The  most  common  one  in  Central  New 
York  is  the  small  snow-fly,  Capnia  pygnma,  which  is  grayish  black.  The 
female  is  9  mm.  (about  f  in.)  long,  with  an  expanse  of  wings  of  16  mm. 
(about  I  in.),  while  the  male  is  but  4§  mm.  (about  \  in.)  long,  and  has 
short  wings  which  extend  but  two-thirds  the  length  of  the  abdomen. 


CHAPTER   VI 

DRAGON-FLIES  AND  DAM- 
SEL-FLIES (Order  Odonata) 

HEN  it  is  high  noon  on  the  mill-pond, — 
when  leaves  droop,  and  sun  glares  upon  the 
water,  and  the  air  is  hot  and  still,  when 
other  creatures  seek  the  shade,  and  even 
the  swallows  that  skim  the  air  morning 
and  evening  are  resting, — then  those  other 
swallows  of  the  insect  world,  the  dragon- 
flies,  are  all  abroad.  .  .  .  One  may  stand 
by  the  side  of  a  small  pond,  and  follow 
for  hours  with  his  eye  the  evolutions  of  one  of  the  large  dragon-flies  skim- 


■l^-^^-lAlel  l-n^ar 


ming   over  the   surface  in  zigzag  Hnes  or   sweeping  curves,  stopping  still 
in  midair,  and  starting  again,  seeming  never  to  rest,  nor  even  to  tire.     Poised 

75 


76 


Dragon-flies  and  Damsel^flies 


in  the  air,  with  the  sunUght  dancing  on  its  trembhng  wings,  it  is  indeed  a 

beautiful  sight. 

"'Dragon-flies?      Folks   call    'em   devil's-darnin'-needles   in   our   parts, 

and  they  say  they  will  sew  up  your  ears.'     Yes;   and  in  some  localities  they 

are  called  'snake-doctors,'  and  are  said 
to  bring  dead  snakes  to  life;  and  other 
meaningless  names  are  given  them,  such 
as  'snake-feeders,'  'horse-stingers,'  'mule- 
killers,'  etc.;  but  in  spite  of  all  these 
silly  names  and  the  silly  superstitions 
they  represent,  dragon-flies  are  entirely 
harmless  to  man  —  are  indeed  to  be 
counted  as  friends,  for  they  destroy  vast 
numbers  of  mosquitoes  and  gnats  and 
pestiferous  little  flies.  To  such  creatures 
they  must  seem  real  dragons  of  the  air. 
While  one  is  standing  by  the  pond  let 
him  follow  awhile  the  actions  of  a  dragon- 
fly that  is  making  short  dashes  in  different 
Fig.  1 10.— a  dragon-fly  (from  life),    directions   close  to  the  bank.      Let  him 

fix   his   eye   on   a   little  fly    hovering  in   the   air,  and  note  that  after  the 

dragon-fly  has  made  a  dart  toward  it,  it  is    gone.      Let    him    repeat    the 

observation  as  the  dragon-fly  goes  darting 

hither  and  thither.     It  will  be  hard  to  see 

the   flies  captured,    so  quickly  it  is  done, 

but  one  can  see  that  '  the  place  that  once 

knew  them    knows  them    no   more.'     And 

the  usefulness  of  the  dragon-fly  in  taking 

off    such    water-haunting    pests    will    be 

appreciated." 

Thus  entertainingly  and  truthfully  writes 

Professor  Needham  of   the  strong-winged, 

brilliantly  colored,  graceful  insects  of  our 

present  chapter.     If  one  could  see  through 

muddy  water  and  would   fix  his  gaze  on 

the  weed-choked  slimy  depths  of  the  pond,  Fig.  m 

he  would  see  the   dragon-flies    in    another 

stage   of    their   life,    under   very    different 

conditions  of   existence,  and  in  very  different  guise.     Crawling   awkwardly 

about  over  and  through   the    decaying   weeds  and  leaves  and  mud  of  the 

bottom    or    lying    in    ambush,    half    concealed    by    coverings    of    slime, 

would  be  seen  certain  strange  big-headed,  thick-bodied,  dirty  gray-green, 


The  young  (nymph)  of 
a  dragon-fly.  (From  Jenkins  and 
Kellogg;    twice  natural  size.) 


Dragon-flies  and  Damsel-flies  'j'j 

wingless  creatures  from  half  an  inch  to  two  inches  long.  Occasionally 
one  of  these  creatures  suddenly  darts  forward  by  spurting  water  from 
the  hinder  tip  of  its  body;  occasionally  one  quickly  thrusts  out  from 
its  head  a  vicious  pincer-like  organ  which  is  more  slowly  withdrawn,  or 
rather  folded  up,  with  an  unfortunate  tiny  water-animal  squirming  in  the 
toothed  pincers.  Still  dragons,  though  now  dragons  of  the  deep  instead  of 
flying  dragons,  these  are  our  insects  in  their  immature  or  larval  life.     Their 


Fig.  112. — Young  (nymph)  dragon-fly,  showing  lower  lip  folded  and  extended.     (From 
Jenkins  and  Kellogg;    twice  natural  size.) 

prey,  consistmg  of  water-bugs,  May-fly  larvae,  small  crustaceans,  mol- 
lusks,  and  any  of  the  numerous  aquatic  insect  larvae,  including  other 
young  dragon-flies,  is  probably  always  caught  alive.  Not  by  active 
pursuit,  as  in  the  air  above,  but  by  lying  in  wait  in  the  murky  depths 
of  the  pond  until  the  unsuspecting  insect  comes  within  reach  of  the 
extensible  lower  lip  with  its  pair  of  broad  spiny,  jaw-like  flaps  at  the 
clutching  tip.  The  fierce  face  of  the  young  dragon,  with  its  great 
mouth  and  sharp  jaws,  is  all  concealed  by  this  lip  when  folded  up, 
and  there  is  little  in  the  appearance  of  the  dirty,  sprawling,  smooth- 
faced creature  to  betray  its  dragon-like  character.  But  appearances  in 
the  insect  world  may  be  as  deceptive  as  in  our  own,  and  too  late  the 
careless  water-bug  out  on  a  foraging  swim  for  lesser  prey  finds  himself  in 
range  of  a  masked  battery  and  becomes  the  preyer  preyed  upon. 

About  three  hundred  different  species  of  dragon-  and  damsel-flies 
(damsel-flies  are  the  smaller,  slender-bodied,  narrow-winged  kinds,  see  Fig. 
113)  are  known  in  North  America,  about  two  thousand  having  been  found 
in  all  the  world.  In  any  single  locality  where  conditions  are  at  aU  favor- 
able to  dragon-fly  life,  that  is,  where  there  are  live  streams  and  ponds,  from 
a  score  to  two  or  three  times  as  many  different  dragon-flies  can  be  found. 
One  hundred  species  occur  in  Ohio,  and  one  hundred  and  twenty  in  New 
York,  states  offering  specially  favorable  natural  conditions  for  them,  while 
only  about  fifty  species  have  been  found  in  California,  a  much  larger  but 
more  arid  region.  The  young  of  no  dragon-fly  species  is  known  to  live  in 
salt  water,  although  nymphs  have  been  found  in  brackish  water  and  in 


78 


Dragon-flies  and  Damsel-flies 


streams  impregnated  with  sulphur  from  sulphur  springs.  Nor  do  dragon- 
flies  like  cold  weather.  Although  a  few  species  are  found  in  the  far  North 
(recorded  at  70°  N.  in  Norway,  65°  N.  in  Alaska,  and  63°  N.  in  Siberia) 
and  a  few  at  high  cold  altitudes  (as  high  as  10,000  feet)  on  mountain  flanks, 
the  great  majority  of  them  need  considerable  temperature  for  growth  and 
development  and  even  for  activity  during  adult  life.  Calvert  says  that  but 
one  species  is  known  which  regularly  passes  the  winter  in  adult  stage,  and 

that  most  dragon-flies  live  as  adults  from 
but  twenty-five  to  forty-five  days,  and 
these  in  the  summer.  In  California,  where 
the  winter  temperature  at  sea-level  only 
occasionally  falls  to  32°  F.,  adult  dragon- 
flies  can  be  found  in  most  of  the  months 
of  the  year. 

The  adult  dragon-flies  are  to  be  seen 
pursuing  their  prey,  like  hawks,  with 
swift  darting  flights  over  ponds,  along 
streams,  and  even  scattered  widely  inland 
over  fields  and  in  woods.  A  few  kinds 
have  a  liking  for  the  vicinity  of  houses. 
Needham,  a  careful  student  of  these 
insects,  has  found  that  the  hunting  region 
above  and  along  the  shores  of  a  pond  may 
be  imaginarily  divided  into  zones  one 
above  the  other,  each  zone  characterized 
by  the  presence  of  a  few  particular 
dragon-fly  species.  "So,  in  fact,"  he  writes,  "we  find  the  smaller  damsel- 
flies  flying  over  the  water  in  a  straight  course  an  inch  or  less  above  the 
surface,  and  rarely  venturing  higher;  the  larger  damsel-flies  a  little  higher; 
the  amber  wings  at  an  average  of  about  six  inches;  the  larger  skimmers 
a  foot  or  more  from  the  surface,  and  upland  skimmers  and  darters  still 
higher.  One  has  only  to  stand  a  little  while  by  some  small  area  of  water 
where  all  these  are  flying  to  see  that  each  keeps  rather  closely  to  his  proper 
altitude.  Why  do  damsel-flies  keep  so  close  to  water?  The  reason  is 
not  far  to  seek.  Dragon-flies  eat  one  another — the  strong  destroy  the 
weak.  If  to  venture  up  into  the  altitude  of  the  larger  species  means  to  run 
the  risk  of  being  eaten,  we  can  readily  see  why  the  damsel-flies  should 
stay  down  below.  The  hawk  may  roam  the  air  at  will,  but  sparrows  must 
keep  to  the  bushes." 

We  think  of  dragon-flies,  as  of  albatrosses  and  Mother  Carey's  chickens, 
as  being  always  on  the  wing.  They  catch  their  prey  while  flying,  eat  it 
while  flying,  mate  while  flying,  and  some  of  them  deposit  their  eggs  while 


Fig.     113.  —  Damsel-flies 
winged    dragon -flies), 
size;  from  life.) 


(narrow- 
(Natural 


Dragon-flies  and  Damsel-flies  79 

on  the  wing.  But  of  course  all  dragon-flies  rest  sometimes,  and  some  of 
them,  especially  the  damsel-flies,  are  at  rest  most  of  the  time,  cHnging  to 
stems  or  leaves  by  the  water's  edge.  The  larger  kinds  may  be  found 
occasionally  perched  on  the  tips  of  tall  swaying  reeds,  or  on  a  stump  or 
projecting  dead  limb.  From  these  coigns  of  vantage  they  swoop  like 
a  hawk  on  any  rash  midge  that  ventures  awing  in  the  neighborhood. 
Cold  or  cloudy  weather,  or  a  strong  wind,  will  drive  most  dragon-flies  to 
shelter. 

The  Odonata  are  unexcelled  among  insects  for  swiftness,  straightness, 
and  quick  angular  changes  in  direction  of  flight.  The  successful  main- 
tenance of  their  predatory  life  depends  upon  this  finely  developed  flight 
function  together  with  certain  structural  and  functional  body  conditions 
which  might  be  said  to  be  accessory  or  auxiliary  to  it.  And  this  may  be 
an  appropriate  place  to  describe  briefly  a  few  of  their  sahent  structural 
characteristics. 

All  dragon-flies  have  four  well-developed  wings,  and  all  show  such  a 
similar  general  bodily  make-up  and  appearance,  that  from  an  acquaintance- 
ship with  two  or  three  familiar  species  any  member  of  the  order  can  be 
recognized  as  really  belonging  to  the  group.  The  body  in  all  is  long,  smooth, 
and  subcylindrical  or  gently  tapering.  This  clean,  slender  body  offers 
little  resistance  to  the  air  in  flight,  and  serves  as  an  effective  steering-oar. 
The  wings  are  long  and  comparatively  narrow,  fore  and  hind  wings  being 
much  alike,  almost  exactly  ahke  indeed  in  the  damsel-flies.  The  venation 
is  of  the  general  type  known  as  net-veining  (Fig.  114b),  the  few  strong  longi- 
tudinal veins  being  connected  by  many  short  cross-veins.  The  fore  wings 
are  greatly  strengthened  along  their  costal  (front)  margin  by  having  the 
first  longitudinal  (subcostal)  vein  behind  the  margin  placed  at  the  bottom 
of  a  groove,  and  the  cross-veins  in  that  groove  so  enlarged  vertically  as 
to  take  on  the  character  of  flat,  plate-like  braces  or  buttresses.  As,  in 
the  figure-of-eight  movement  of  the  wing  in  flight,  the  front  margin  first 
meets  the  resistance  of  the  air,  it  is  necessary  that  swiftly  and  strongly  beat- 
ing wings  should  be  especially  strengthened  along  this  edge,  and  this  is  just 
what  the  peculiar  folding  and  bracing  of  the  costal  region  of  the  dragon-fly's 
fore  wing  accomplishes. 

The  head  is  unusually  large  and  is  more  than  two-thirds  composed  of 
the  pair  of  great  compound  eyes.  More  than  30,000  facets  have  been 
counted  in  the  cornea  of  certain  dragon-fly  species,  and  this  means  that  each 
eye  is  made  up  of  more  than  30,000  distinct  eye-elements  or  ommatidia, 
each  capable  of  seeing  a  small  part  or  point  of  any  object  in  range  of  vision. 
Thus  an  image  of  a  near-by  object  is  made  in  fine  mosaic,  and  the  finer  the 
mosaic  the  more  definite  and  precise  is  the  vision  by  means  of  compound 
eyes.     These  great  eyes,  too,  have  facets  directed  up  and  down  and  sidewise 


8o  Dragon-flies  and  Damsel-flies 

as  well  as  forward,  and  by  a  special  sort  of  articulation  of  the  head  on  the 
thorax  it  can  be  rotated  readily  through  i8o°,  so  that  the  principal  part  of 
each  eye  can  be  directed  sidewise  or  even  straight  down.  For  accurate 
flight  and  successful  pursuit  of  flying  prey  the  dragon-fly  has  full  need  of 
good  eyes.  It  is  to  be  noted,  too,  that  the  eyes  are  relatively  largest  in  those 
particular  dragon-fly  kinds  which  have  the  most  powerful  flight.  On  the 
head,  also,  are  three  simple  eyes  (ocelli),  the  pair  of  very  small  awl-like 
antennae,  and  the  great  mouth.  The  mouth  is  overhung  as  by  a  curtain 
by  the  large  flap-like  upper  lip  (labrum).  The  jaws  (mandibles)  are  strong 
and  toothed,  and  obviously  well  adapted  for  tearing  and  crushing  the  cap- 
tured prey. 

When  the  prey  is  come  up  with,  however,  it  is  caught  not  by  the  mouth 
but  by  the  "leg-basket."  The  thorax  is  so  modified,  and  the  insertion  of 
the  legs  such,  that  all  the  legs  are  brought  close  together  and  far  forward, 
so  that  they  can  be  clasped  together  like  six  slender,  spiny  grasping  arms 
just  below  the  head.  Although  the  catching  and  eating  is  all  done  in  the 
air  and  very  quickly,  observers  have  been  able  to  see  that  the  prey  is  caught 
in  this  "leg-basket"  and  then  held  in  the  fore  legs  while  being  bitten  and 
devoured.  These  slender  legs  are  used  only  very  slightly  for  locomotion, 
but  they  serve  well  for  the  light  unstable  perching  which  is  characteristic 
of  the  dragon-flies.. 

The  internal  anatomy  is  specially  characterized,  as  might  well  be 
imagined,  by  a  finely  developed  system  of  thoracic  muscles  for  the  rapid 
and  powerful  motion  of  the  wings  and  the  delicate  and  accurate  move- 
ments of  the  legs.  The  respiratory  system  is  also  unusually  well  developed, 
such  active  insects  needing  a  large  quantity  of  oxygen,  and  generating  a 
large  amount  of  carbon  dioxide.  The  respiratory  movements,  according 
to  Calvert,  consist  in  an  alternate  expansion  (inspiration  through  the  ten 
pairs  of  breathing-holes,  or  spiracles,  arranged  segmentally  on  thorax  and 
abdomen)  and  contraction  (expiration)  of  the  abdomen.  The  rate  of 
movement  varies  greatly  at  difl'erent  times  owing  to  unknown  causes,  but 
is  always  quickened  by  exercise,  increased  temperature,  or  mechanical  irri- 
tation. In  different  dragon-flies  the  inspirations  have  been  noted  to  be 
from  73  to  ii8  a  minute. 

The  dragon-flies  are  famous  for  their  beautiful  metallic  colors.  As  they 
dart  through  the  air  one  gets  glimpses  of  iridescent  blue  and  green  and  cop- 
per, of  tawny  red  and  violet  and  purple  reflections  that  are  most  fascinating 
and  tantalizing.  Seen  close  at  hand  in  the  collections,  however,  they  are 
mostly  dull-colored  and,  except  for  their  "pictured"  wings  and  the  sym- 
metry and  trim  outline  of  their  body,  rather  unattractive  "specimens."  But 
a  freshly  caught  dragon-fly  shows  the  real  glory  of  the  coloring:  delicate 
changing  shades  of  green  and  violet  and  copper  quiver  in  the  great  eyes; 


Dragon-flies  and  Damsel-flies  8 1 

the  thorax  is  transkicent  green  or  blue,  and  the  long  symmetrical  body  is 
warm  red  or  deep  blue  or  purple  or  green.  It  is  often  covered  with  a  soft 
whitish  "bloom,"  that  tones  down  the  brilliant  metallic  iridescence.  But 
as  the  body  dries,  the  colors  fade.  They  are  due  not  so  much  to  pigment 
as  to  the  interference  in  reflection  of  the  various  color-rays,  this  interference 
being  caused  by  the  structure  of  the  body-wall.  Just  as  soap-bubbles  or 
weathered  plates  of  glass  or  mica  produce  brilliant  colors  by  interference 
effects,  so  does  the  semi-transparent  laminate  outer  body-wall  of  the 
dragon-fly  produce  its  fleeting  color  glories.  While  the  wings  of  many 
kinds  are  clear,  unmarked  by  blotches  or  line,  the  wings  of  others  bear  a 
definite  "picture"  or  pattern,  usually  light  or  dark  brown  or  even  blackish, 
reddish,  thin  yellow,  or  whitish.  These  wing-patterns  make  the  determination 
of  many  of  the  dragon-fly  species  a  very  simple  matter. 

When  the  dragon-flies  go  winging  about  over  ponds  and  streams  they 
are  engaged  in  one  of  three  things:  in  eating,  in  mating,  or  in  egg-laying. 
The  prey  of  the  dragon-fly  may  be  almost  any  flying  insect  smaller  than 
itself,  although  midges,  mosquitoes,  and  larger  flies  constitute  the  majority 
of  the  victims.  Howard  says  that  the  voracity  of  a  dragon-fly  may  easily 
be  tested  by  capturing  one,  holding  it  by  its  wings  folded  together  over  its 
back,  and  then  feeding  it  on  Hve  house-flies.  Beutenmiiller  found  that 
one  of  the  large  ones  would  eat  forty  house-flies  inside  of  two  hours.  Howard 
says  that  a  dragon-fly  will  eat  its  own  body  when  offered  to  it  (query,  to 
its  head?)  and  that  a  collected  dragon-fly,  if  insufficiently  chloroformed  and 
pinned,  will  when  it  revives  cease  all  efforts  to  escape  if  fed  with  house-flies, 
the  satisfying  of  its  appetite  making  it  apparently  oblivious  to  the  discom- 
fort or  possible  pain  of  a  big  pin  through  its  thorax.  That  dragon-flies 
are  sometimes  cannibalistic  has  been  repeatedly  confirmed  by  observation. 
The  nymphs  have  been  seen  to  devour  nymphs  of  their  own  and  other 
species;  the  nymphs  of  a  European  form  have  been  observed  to  come  out  of 
water  at  night  and  attack  and  devour  newly  transformed  imagoes  of  the 
same  species,  while  several  instances  are  recorded  of  the  capture  and  devouring 
of  an  imago  of  one  species  by  an  imago  of  another. 

The  good  that  is  done  by  dragon-flies  through  their  insatiable  appetite 
for  mosquitoes  is  very  great.  Now  that  we  recognize  in  mosquitoes  not 
only  irritating  tormentors  and  destroyers  of  our  peace  of  mind,  but  alarm- 
ingly dangerous  disseminators  of  serious  diseases  (malaria,  yellow  fever, 
filariasis),  any  enemy  of  them  must  be  called  a  friend  of  ours.  A  prize  was 
once  offered  for  the  best  suggestions  looking  toward  practicable  means  of 
artificially  utilizing  dragon-flies  for  the  destruction  of  mosquitoes  and  house- 
flies,  but  no  very  efficient  improvement  on  the  dragon-fly's  natural  tastes 
and  practices  were  brought  out  by  this  essay  competition. 

In  Honolulu,  the  principal  city  of  our  mid-Pacific  territory,  the  mosqui- 


82  Dragon-flies  and  Damsel-flies 

toes  are  so  abundant  that  no  one  neglects  to  enclose  his  bed  carefully  each 
night  in  mosquito-netting,  and  all  bedrooms  are  equipped  with  an  ingenious 
canopy  which  can  be  folded  closely  in  the  daytime  and  readily  spread  over 
the  bed  at  night.  The  continuous  and  abundant  presence  of  mosquitoes 
is  such  a  matter  of  fact  that  it  has  dictated  certain  particular  habits  of  life 
to  the  inhabitants  of  Honolulu.  But  in  the  daytime  one  is  singularly  free 
from  mosquito  attack.  Coincidentally  with  this  one  notes  the  surprising 
abundance  and  strangely .  domestic  habits  of  great  dragon-flies.  I  have 
watched  dozens  of  dragon-flies  hawking  about  a  hotel  lanai  (porch)  in  the 
heart  of  the  town.  No  pond  or  stream  is  nearer  than  the  city's  outskirts. 
Dragon-flies  are  in  the  main  streets,  in  all  the  gardens,  and  they  are  chiefly 
engaged  in  the  laudable  business  of  hunting  the  hordes  of  "day"  mosquitoes 
to  their  death.  The  most  conspicuous  features  of  insect  life  in  Hawaii  are 
the  hosts  of  dragon-flies  by  day  and  the  hordes  of  mosquitoes  by  night.  As 
the  dragon-flies  unfortunately  are  not  night  flyers  (although  some  forms 
keep  up  the  hunting  until  it  is  really  dark),  it  is  by  night  that  one  realizes 
what  a  plague  the  mosquito  is  in  the  islands.  Were  it  not  for  the  dragon- 
flies,  life  in  the  islands  would  be  nearly  intolerable.  The  rice-swamps  and 
taro-marshes  and  the  heavily  irrigated  banana  and  sugar  plantations  offer 
most  favorable  breeding-grounds  for  the  mosquitoes,  but  also  fortunately 
for  the  dragon-flies  as  well.  The  mosquitoes  of  Hawaii  are  not  indigenous; 
they  were  introduced  with  white  civilization.  It  is  told,  and  is  not  improb- 
able, that  the  skipper  of  a  trading  schooner  in  early  days,  to  revenge  himself 
for  some  slight  put  on  him  by  the  natives,  purposely  put  ashore  a  cask  of 
water  swarming  with  mosquito  wrigglers.  It  needed  no  more  than  that 
to  colonize  this  fascinating  tropic  land  with  the  mosquito  plague.  How 
the  saving  dragon-flies  came  is  not  yet  come  to  be  tradition;  indeed,  few 
Hawaiians  understand  how  important  a  part  the  dragon-fly  plays  in  their 
life.     They  do  appreciate  the  mosquito. 

In  the  Samoan  Islands,  too,  where  we  have  another  tropical  colony, 
the  mosquitoes  are  a  great  plague.  Here  the  matter  is  made  more  serious. 
The  Samoan  mosquitoes  are  carriers  and  disseminators  of  a  dreadful  disease 
known  as  elephantiasis  from  the  enormous  enlargement  of  the  legs  and 
arms  of  sufferers  from  it.  This  disease  is  the  great  scourge  of  these  islands, 
more  than  30%  (from  my  own  observation;  40%  and  50%  are  estimates 
given  by  other  observers)  of  the  natives  having  it.  (For  an  account  of 
the  role  of  mosquitoes  in  the  dissemination  of  malaria,  yellow  fever,  and 
elephantiasis,  see  Chapter  XVIII  of  this  book.)  The  dragon-flies  are,  in 
Samoa  as  in  Hawaii,  conspicuous  by  their  abundance  and  variety,  and  they 
do  much  to  keep  in  check  the  quickly  breeding  mosquitoes. 

Watching  the  flying  dragon-flies  over  a  pond,  you  may  occasionally 
see  one  poising  just  over  the  surface  of  the  water,  and  striking  it  with  the 


Dragon-flies  and  Damsel-flies 


83 


tip  of  the  abdomen;   or  another  kind  may  be  seen  to  swoop  swiftly  down  to 
the  surface  occasionally  in  its  back-and-forth  flight,  and  to  dip  the  tip  of 


Fig.   114a. 


Fig.   1 146. 
Stages  in  the  development  of  the  giant  dragon-fly,   Anax  Junius,     a,  youngest  stage;  b, 
c,  and  d,  older  stages,  showing  gradual  development  of  the  wings.     (Young  stage, 
slightly  enlarged  after  Needham;   adult  three-fourths  natural  size.) 

the  body  for  a  moment  into  the  water.  These  are  females  engaged  in  laying 
their  eggs.  The  eggs  issue  in  small  masses,  usually  held  together  by  a  gelat- 
inous substance.     From  several  hundred  to  several  thousand  eggs  are  laid  by 


84 


Dragon-flies  and  Damsel-flies 


each  female.  Needham  counted  110,000  eggs  in  a  single  egg-mass  of  Libellula. 
Sometimes  the  eggs  may  be  laid  on  wet  mud  or  attached  to  moist  water-  or 
shore-plants.  The  damsel-flies  and  a  few  of  the  dragon-flies  insert  the  eggs 
in  the  stems  of  dead  or  living  water-plants  below  the  surface  of  the  water. 
To  do  this  they  have  to  cling  to  the  stem,  with  the  abdomen  or  sometimes 
the  whole  body  under  water,  and  cut  slits  in  it  with  the  sharp  ovipositor. 
The  eggs  are  sometimes  laid  on  submerged  timbers  and  moss-  or  alga-covered 
stones.  Kellicott  observed  females  of  A  rgia  putrida  (a  damsel-fly  abundant 
along  Lake  Erie)  to  remain  wholly  under  water  for  from  five  to  fifty-five 
minutes  at  a  time.  These  females  were  accompanied  by  males  which  also 
stayed  under  for  similar  lengths  of  time. 

The  eggs  hatch  after  various  periods,  depending  on  the  species  of  dragon- 
fly and  on  the  time  of  year  of  oviposition.  In  midsummer  Needham  found 
the  eggs  of  some  species  to  hatch  in  from  six  to 
ten  days,  while  others  laid  in  autumn  did  not  hatch 
until  the  following  spring.  In  the  same  lot  of  eggs 
the  period  of  incubation  may  vary  even  in  midsum- 
mer from  a  week  to  more  than  a  month. 

From  the  eggs  come  tiny,  spider-like  nymphs 
with  long,  slender  legs,  thin  body,  and  no  sign  of 
wings.  Even  in  the  largest  dragon-fly  species  the 
just-hatched  young  are  only  about  one-twelfth  of 
an  inch  long,  while  the  nymphs  of  the  common 
Libellulas  are  only  one-twenty-fifth  of  an  inch  long 
at  hatching.  They  begin  their  predatory  life,  con- 
fining their  attention  at  first  to  the  smaller  aquatic 
creatures,  but  with  increasing  size  and  strength 
and  confidence  being  ready  to  attack  almost  any  of 
the  under-water  dwellers.  Even  fish  are  seized  by 
the  larger  nymphs,  Needham  having  seen  the 
nymphs  of  one  species  seize  and  devour  young 
brook-trout  as  long  as  themselves. 

The  young  of  different  species  differ  consider- 
ably in  size,  shape,  and  duration  of  their  nymphal 
existence.  The  nymphs  of  some  species  require 
more  than  a  year  to  develop  into  adults,  while  those  of  some  others  are  ready 
to  transform  in  a  few  months,  not  a  few  dragon-fly  species  having  two  gener- 
ations a  year.  The  one-year  life  cycle,  however,  is  usual  among  the  more 
familiar  dragon-flies,  the  eggs  laid  during  midsummer  hatching  in  late  sum- 
mer, the  nymphs  hibernating  and  being  ready  to  emerge  the  following  sum- 
mer. Needham  thinks  that  the  damsel-flies  have  a  number  of  broods  in 
a  season,  the  processes  of  transformation  and  oviposition  beginning  as  soon 


Fig.  115. — The  young 
(nymph)  of  a  damsel- 
fly  (narrow-winged  dra- 
gon-fly), Lestes  sp.  The 
three  leaf -like  processes 
at  the  tip  of  the  abdo- 
men are  gills  (Twice 
natural  size.) 


Dragon-flies  and  Damsel-flies  85 

as  the  weather  permits,  and  continuing  industriously  to  the  close  of  the 
season. 

The  nymphs  cast  the  skin  repeatedly  during  their  growth  and  develop- 
ment, although  the  exact  number  of  moultings  is  not  known  for  any  species. 
After  two  or  three  moults  the  wing-pads  appear  and  with  each  successive 
moult  increase  in  size.  Immediately  after  moulting  the  nymphs  are  Ught 
greenish  or  gray,  and  their  characteristic  color  pattern  is  distinct,  but  they 
gradually  darken,  the  pattern  becoming  more  and  more  obscure  until  by 
the  t'me  for  another  moulting  the  body  is  uniformly  dark  and  dingy.  The 
nymphs  (Fig.  115)  of  the  damsel-flies  are  elongate  and  slender,  and  have 
three  long  conspicuous  gill-plates  at  the  tip  of  the  abdomen,  which  they 
can  also  use  as  sculls  for  swimming.  The  dragon-fly  nymphs  are  robust- 
bodied,  some  of  them  indeed  having  the  abdomen  nearly  as  wide  as  long 
and  much  flattened.  All  the  nymphs  are  provided  with  the  long  grasping 
lower  lip,  which  can  be  folded  mask-like  over  the  face  when  not  engaged 
in  seizing  prey.  The  mandibles  are  strong  and  sharp  and  the  whole  mouth 
is  well  fitted  for  its  deplorable  but  necessary  business. 

The  true  dragon-fly  nymphs  do  not  have  plate-like  gills,  like  those  of  the 
damsel-flies,  nor  any  other  external  kind,  but  have  the  posterior  third  of 
the  intestine  lined  with  so-called  internal  gills.  These  internal  or  rectal 
gifls  are  in  six  longitudinal  bands,  each  consisting  of  two  thin  rows  of  small 
plates  or  tufts  of  short  slender  papillae.  Water  is  taken  into  the  intestine 
through  its  posterior  opening  and,  after  bathing  the  gills,  giving  up  its  dis- 
solved oxygen,  and  taking  up  carbon  dioxide,  it  is  ejected  through  the  same 
opening.  When  this  water  is  ejected  violently  it  serves  to  propel  the  nymph 
forward.     It  is  also  apparently  occasionally  used  for  defence. 

Just  as  the  adult  flying  dragon-flies  keep  to  certain  regions  above  or 
in  the  neighborhood  of  the  pond,  so  Needham  has  found  the  nymphs  to 
have  various  preferred  lurking-places  in  the  pond.  The  damsel-fly  nymphs 
and  a  few  of  the  more  active  dragon-fly  nymphs  clamber  among  submerged 
vegetation  or  inhabit  driftwood  and  submerged  roots  or  brush.  The  heavier 
sprawling  Libellulid  nymphs  usually  crawl  over  the  bottom  or  climb  over 
fallen  rubbish,  while  certain  other  Libelluhds  and  some  similar  forms  occupy 
the  mud  or  sand  of  the  bottom.  The  nymphs  of  one  of  these  latter  kinds 
is  described  as  each  scratching  a  hole  for  itself  and  descending  into  it  like 
a  chicken  into  a  dust-bath,  kicking  the  sand  over  its  back  and  burrowing 
until  all  but  hidden,  only  the  tops  of  its  eyes,  the  tips  of  its  treacherous  labium, 
and  the  respiratory  aperture  at  the  end  of  the  abdomen  reaching  the  surface. 

After  the  few  weeks  or  month  or  year  which  the  nymph  requires  for  its  full 
growth  and  development  it  is  ready  to  transform.  If  in  early  summer,  when 
the  dragon-flies  are  beginning  to  appear,  one  will  go  out  to  the  dragon-fly 
pond  a  little  after  daylight,  he  will  see  this  transforming  or  issuance  of  the 


86 


Dragon-flies  and  Damsel-flies 


winged  imagoes  busily  going  on.  The  nymphs  crawl  out  of  the  water,  and 
up  on  stones  or  projecting  sticks,  or  on  bridge-piles  or  the  sides  of  boats, 
or  on  the  stems  of  weeds  growing  by  the  water's  edge.    Here  they  cling  quietly, 

awaiting  the  moment  when  the  chi- 
tinous  body-wall  shall  split  lengthwise 
along  the  back  of  the  thorax,  and  the 
made-over  body  inside  with  its  damp, 
compressed  wings,  its  delicate  trans- 
parent skin,  and  changed  mouth-parts 
and  legs  shall  slowly  work  its  way  out 
of  the  old  nymphal  coat.  The  nymphs 
of  some  dragon-flies  and  damsel-flies 
crawl  out  among  the  weeds  and  grass 
of  the  shore  for  some  distance  before 
choosing  a  resting-place,  and  none  of 
these  will  be  very  readily  seen.  But  careful  searching  in  a  place  from  which 
winged  individuals  are  occasionally  arising  will  soon  reveal  the  transforming 
in  all  of  its  stages  (Fig.  ii6).  It  takes  some  time  for  the  emergence  of  the 
damp,  soft  imago  from  the  nymphal  skin,  and  some  further  time  for  the 
slow  expanding  and  drying  of  the  wings,  and  the  hardening  of  the  body- 
wall  so  that  the  muscles  can  safely  pull  against  it.  When  all  this  has  come 
about  the  imago  can  fly  away.     But  even  yet  the  colors  are  not  fully  acquired 


Fig.  ii6. — The  issuance  of  an  adult  white 
tail,  Plathemis  trimaculata.  (After  Need- 
ham;    natural  size.) 


Fig.  117. — Adult  and  last  exuvia  of  the  whitetail,  Plathemis  trimaculata. 
(Natural  size.) 

and  fixed,  and  these  fresh  imagoes  have  an  unmistakably  new  and  shiny 
appearance.  They  are  called  teneral  specimens.  Usually  the  emergence 
of  nymphs  from  the  pond  and  the  subsequent  transforming  cease  by  the 
middle  of  the  forenoon,  and  after  that  one  can  find  only  the  frail,  drying 


Dragon-flies  and  Damsel-flies 


87 


Adult  and  last  exuvia  of  the  damsel- 
fly,  Lestes  uncata.     (Natural  size.) 


cast  nymphal  skins  or  exuvicX,  clinging  here  and  there  to  stones  and  plant- 
stems.  Attached  to  these  exuvice  there  may  be  often  noted  two  or  three  short, 
white,  thread-like  processes.  These 
are  the  dry  chitinous  inner  linings 
of  the  main  tracheal  trunks  of  the 
dragon-fly  which  were  moulted  with 
the  outer  body-wall.  As  the  main 
tracheal  tubes  are  really  invagina- 
tions of  the  outer  skin,  it  is  obvious 
that  the  inner  lining  of  the  trachea 
is  continuous  with  the  outer  coat 
(chitinized  cuticle)  of  the  body-wall 
and  so  is  naturally  cast  off  with  it. 
Although  the  habits  of  the  adult 
dragon-flies  must  be  studied  out  of 
doors,  the  nymphs  can  be  brought 
indoors  and  kept  alive  so  that  their 
walking  and  swimming  and  hiding  Fig.  118 
and  capturing  of  prey,  and  often 
their  transformation  into  winged  imagoes,  can  be  readily  observed.  In 
their  natural   habitat   some    of    these  observations   are    nearly    impossible, 

and  for  school-room  or  private-study  aquaria 
hardly  any  other  animals  can  be  found  of 
more  interest  to  the  observer,  whether  child  or 
grown-up,  than  the  dragon-fly  nymphs. 

Professor  Needham,  who  has  done  more 
and  better  work  in  the  study  of  the  immature 
life  of  dragon-flies  than  anybody  else,  gives 
the  following  directions  for  collecting  and 
rearing  the  nymphs: 

"If  one  wishes  to  collect  the  nymphs  which 
lie  sprawling  amid  fallen  trash,  a  garden-rake 
with  which  to  draw  the  trash  aside,  fingers  not 
too  dainty  to  pick  them  up  when  they  make 
themselves  conspicuous  by  their  active  efforts 
to  get  back  into  the  water,  and  a  pail  of 
water  in  which  to  carry  them  home,  are  all 
-A  home-made  water-  the  apparatus  required, 
collecting  dragon-fly  "A  rake  will  bring  ashore  those  other 
(After  Needham.)  ^y^^^is  which  burrow  shallowly  under  the 
sediment  that  lies  on  the  bottom,  and  also  a  few  of  those  that  cling  to  vegeta- 
tion near  the  surface;    but  for  getting  these  latter  a  net  is  better.     Fig.  119 


Fig.  iiq.- 
net  for 
nymphs. 


88 


Dragon-flies  and  Damsel-flies 


shows  the  construction  of  a  good  water-net  that  can  be  made  at  home  out 
of  a  piece  of  grass-cloth,  two  sizes  of  wire,  and  a  stick. 

"The  best  places  to  search  for  dragon-fly  nymphs  in  general  are  the 
reedy  borders  of  ponds  and  the  places  where  trash  falls  in  the  eddies  of 
creeks.  The  smaller  the  body  of  water,  if  permanent,  the  more  likely  it 
is  to  yield  good  collecting.  The  nymphs  may  be  kept  in  any  reasonably 
clean  vessel  that  will  hold  water.  Some  clean  sand  should  be  placed  in 
the  bottom,  especially  for  burrowers,  and  water-plants  for  damsel-fly  nymphs 
to  rest  on.  They  may  be  fed  occasionally  upon  such  small  insects  (smaller 
than  themselves)  as  a  water-net  or  a  sieve  will  catch  in  any  pond.  Their 
habits  can  be  studied  at  leisure  in  a  dish  of  water  on  one's  desk  or  table. 

"The  best  season  for  collecting  them  is  spring  and  early  summer.  April 
and  May  are  the  best  months  of  the  year,  because  at  this  time  most  nymphs 

are  nearly  grown,  and,  if  taken  then, 
will  need  to  be  kept  but  a  short  time 
before  transforming  into  adults.  And 
this  transformation  every  one  should 
see;  it  will  be  worth  a  week's  work  at 
the  desk;  and  as  it  can  be  appreciated 
only  by  being  seen,  some  simple  direc- 
tions are  here  given  for  bringing  the 
Fig.  1 20.— a  simple  aquarium  for  rear-  ^ymphs  to  maturity.  Place  them  in  a 
ing  dragon-fly  nymphs.     (After  Need-      •'     ^  •' 

ham.)  wooden    pafl    or   tub    (Fig.    120).       if 

the  sides  are  so  smooth  that  they  cannot  crawl  up  to  transform,  put  some 
sticks  in  the  water  for  them  to  crawl  out  on.  Tie  mosquito-netting  tightly  over 
the  top,  or,  better,  make  a  screen  cover;  leave  three  or  four  inches  of  air 
between  the  water  and  the  netting;  feed  at  least  once  a  week,  set  them  where 
the  sun  will  reach  them;  and  after  the  advent  of  warm  spring  weather  look 
in  on  them  early  every  morning  to  see  what  is  going  on." 

Elsewhere  Professor  Needham  says  that  nymphs  may  be  fed  bits  of 
fresh  meat  in  lieu  of  live  insects.  If  meat  is  fed,  it  must  be  kept  in  motion 
before  them,  as  they  will  refuse  anything  that  does  not  seem  alive.  Some 
nymphs  will  take  earthworms.  Care  must  be  taken  to  keep  cannibalistic 
kinds  apart  from  others.  When  the  nymphs  transform  the  freshly  issued 
imagoes  should  be  transferred  each  with  its  cast  skin  (exuvia)  to  dry  boxes 
for  a  short  time,  till  their  body-wall  and  wings  gain  firmness  and  the  colors 
are  matured.     The  imago  and  its  exuvia  should  always  be  kept  together. 

Specimens  of  the  adults  for  the  cabinet  should  have  the  wings  spread 
like  butterflies  and  moths  (for  directions  for  spreading  see  the  Appendix). 
The  slender  and  brittle  dried  abdomen  breaks  off  very  easily,  and  a  bristle 
or  fine  non-corrosive  wire  should  therefore  be  passed  lengthwise  through 
the  body  as  far  as  the  lip  of  the  abdomen.     A  couple  ot  insect-pins,  inserted 


Dragon-flies  and  Damsel-flies  89 

lengthwise  one  at  each  end  of  the  body,  are  used  by  some.  Specimens 
intended  for  exchange  should  not  be  pinned  up,  but  "papered,"  i.e.,  put 
with  folded  wings  into  an  enclosing  little  triangular  paper  envelope  made 
by  folding  an  oblong  paper  sheet  once  diagonally  and  then  folding  over 
slightly  the  two  margins. 

i  %v        /     /■     /    ■■■       A.  P 


Fig.  121. — Diagram  of  venation  of  wing  of  dragon-fly.     a,  antecubitals;   b,  postcubitals; 
N,  nodus;  P,  pterostigma;  A,  arculus;  t,  triangle.      (After  Banks.) 

TABLES  FOR  CLASSIFICATION. 

Key  to  Suborders  (Imagoes). 

Front  and  hind  wings  nearly  similar  in  outline,  and  held  vertically  over  the  back 
when  at  rest;    head  wide  and  with  eyes  projecting  and  constricted  at  base. 

(Damsel-flies.)     Suborder  Zygoptera. 

Front  and  hind  wings  dissimilar,  hind  wings  usually  being  much  wider  at  base,  and 

both  pairs  held  horizontally  outstretched  when  at  rest;    eyes  not  projecting 

and  constricted  at  base (Dragon-flies.)     Suborder  Anisoptera. 

Key  to  Suborders  (Nymphs). 
Posterior    tip    of    abdomen    bearing    three,    usually    long,    leaf-like    tracheal    gills. 

(Damsel-flies.)     Suborder  Zygopter.a. 
Posterior    tip    of    abdomen    with    five,    converging,  short,    spine-like    appendages. 

(Dragon-flies.)     Suborder  Anisoptera. 

SUBORDER   ZYGOPTERA. 
Key  to  Families  (Imagoes). 

Wings   with   not   less   than   five   antecubital   cross-veins   (Fig.    121). 

Family  Calopterygid^. 
Wings  with  not  more  than  three,  usually  two,  antecubitals  (Fig.  121). 

Family  Agrionid,e. 
Key  to  Families  (Nymphs). 

Basal  segment  of  the  antennae  extremely  elongate Family  Calopterygid.e. 

Basal  segment  of  the  antennae  short,  subrotund Family  Agrionid^. 

The  family  Calopterygidae  includes  but  two  genera,  Calopteryx,  in  which 
the  basilar  space  of  the  wings  is  open  and  the  wings  themselves  are  rather 
broad  near  the  tip,  and  Hetaerina,  in  which  the  basilar  space  is  net-veined 
and  the  wings  narrow. 

Calopteryx  maculata  (Fig.  122),  the  most  familiar  representative  in  the 
Eastern   States  of   the  first   genus,  has  velvety  black  spoon-shaped  wings, 


90 


Dragon-flies  and  Damsel-flies 


Fig.    122. 


-The  black  wing,  Calopteryx 
macula  ta. 


(brownish  in  freshly  moulted,  or  teneral  specimens),  and  a  long,  slender  body, 
of  striking  metallic  blue  or  green.  The  females  can  be  distinguished  from 
the  males  by  their  possession  of  a  milk-white  pterostigma  (Fig.  121).  These 
beautiful  "black  wings"  are  found  'n  gentle  fluttering  flight,  usually  along 
small  streams  in  woods  or  meadows.     The  female  lays  her  eggs  "among 

the  rubbish  and  mud  along  the 
borders  of  ditches,"  and  the 
nymphs  found  in  the  ditches 
and  streamlets  have  the  middle 
one  of  the  three  caudal  gills  fiat 
and  shorter  than  the  other  two. 
Kellicott  has  seen  the  males  of 
this  species  fight  fiercely  with 
each  other.  "Two  will  fly  about 
each  other,  evidently  with  con- 
suming rage,  when  one  finally 
appears  to  have  secured  a  posi- 
tion of  advantage  and  darts  at 
his  enemy,  attempting,  often  suc- 
cessfully, to  tear  and  damage 
his  wings." 

The  best  known  representative  of  the  other  genus  is  a  perfect  master- 
piece of  insect  beauty  and  grace.  Entomologists  know  it  as  Hetcerina 
americana  (Fig.  123);  I  suggest  that  we  call  it  the  "ruby-spot,"  although 
only  the  males  bear  the  gem.  The  head  and  thorax  of  the  males  are 
coppery  red,  the  abdomen  me- 
tallic green  to  coppery,  and  the 
basal  fourth  of  each  of  the  long, 
slender,  and  otherwise  clear  wings 
is  bright  blood-red.  In  the  females 
the  whole  body  is  metallic  green, 
with  the  basal  third  of  the  wings 
pale  yellowish  brown.  These  dam- 
sel-fiy  beauties  are  shy  and  retiring, 
rarely  venturing  more  than  a  few 
feet  away  from  the  willow-overhung 
bank  of  their  favorite  swift-running 
stream.  Sometimes  hundreds  of 
them  come  together  and  chng  in 
graceful  festoons  to  the  drooping  willow  branches.  Then  they  look  like 
strings  of  rubies,  or  of  warm  red  flowers  or  seeds. 

The  family  Agrionidae  includes  the  host  of  slender-bodied,  narrow-  and 


Fig.  123. — The  ruby-spot,  Hetcerina 
americana. 


Dragon-flies  and  Damsel-flies  91 

clear-winged  true  damsel-flies.  Most  of  them  are  small,  and  many  keep 
so  closely  in  low  herbage  or  shrubby  woodland  that  they  attract  little  atten- 
tion. A  few  of  the  longer-bodied  and  longer-winged  forms,  however,  fly 
in  the  open  along  the  stream-banks  or  over  the  ponds.  Some  are  strikingly 
varied  with  black  and  orange  or  yellow,  and  all,  whether  brightly  colored 
09-  dull,  are  graceful  and  charming.  There  are  at  least  a  dozen  genera  of 
Agrionids  in  this  country,  comprising  about  seventy-five  species,  but  their 
classification  is  too  difficult  to  be  undertaken  by  general  students.  Damsel- 
flies  deposit  their  eggs  in  the  tissue  of  aquatic  plants  by  cutting  slits  in  the 
stems  with  their  sharp  ovipositor.  The  nymphs  are  slender  and  elongate, 
and  can  readily  be  known  by  the  three  caudal  leaf-like  tracheal  gills.  The 
nymph  stage  of  these  forms  is  much  shorter  than  with  the  true  dragon-flies, 
lasting  usually  probably  but  a  few  weeks,  or  at  most  two  or  three  months. 
When  ready  to  transform  the  nymphs  crawl  out  of  the  water  and  into  the 
low  herbage  on  the  stream  or  pond  bank.  I  have  seen  scores  of  freshly 
emerged  damsel-flies  rising  from  a  few  square  yards  of  tall  grass  near  a  pond, 
although  it  required  close  search  to  discover  the  nymphs,  so  well  concealed 
were  they  in  the  dense  tangle. 

SUBORDER  ANISOPTERA. 

Key  to  Families  (Imagoes). 

Antecubitals  of  the  first  and  second  rows  mostly  meeting  each  other;  triangle  of 
fore  wings  with  long  axis  at  right  angles  to  the  length  of  the  wings,  triangle 
of  hind  wing  with  long  axis  in  direction  of  the  length  of  the  wing. 

LiBELLULID.E. 

Antecubitals  of  the  first  and  second  rows  not  meeting  (or  running  into  each  other) 
except  the  first  and  another  thick  one;    triangles   of  fore  and  hind  wings  of 
similar  shape   (Fig.    121). 
Eyes  meeting  above  on  middle  line  of  head;    abdomen  with  lateral  ridges. 

JESCUNIBM. 

Eyes  just  touching  at  a  single  point  or  barely  apart;   abdomen  without  lateral 

ridges Cordulegasterid^. 

Eyes  distinctly  separated;    abdomen  without  lateral  ridges Gomphid^. 

Key  to  Families  (Nymphs). 
Under-lip  (labium)  flat,  not  concealing  most  of  the  face,  with  jaw-like  or  oblong 
side  pieces  (lateral  lobes). 

Antennae    7-segmented,    tarsi    3-segmented,    climbing    nymphs.  ..(Eschnid.e. 
AntenucB  4-segmented,    the   fourth   segment   rudimentary;    fore   tarsi   2-seg- 

mented;    burrowing  nymphs Gomphid^. 

Under-lip  (labium)  spoon-shaped,  covering  most  of  the  face,  when  closed,  with  nearly 
triangular   side    pieces    (lateral    lobes). 

Two  stout  teeth  with  a  notch  between  them  on  the  middle  lobe  of  the  under- 
lip  (labium) '. Cordulegasteridj!:. 

A  single  median  tooth  on  the  middle  lobe  of  the  under-lip LibelluliDjE. 


92  Dragon-flies  and  Damsel-flies 

The  family  Cordulegasteridae  includes  only  seven  species  of  dragon-flies 
found  in  the  United  States,  all  belonging  to  one  genus,  Cordulegaster.  They 
are  large,  with  eyes  barely  touching  on  top  of  the  head,  without  metallic 
body-colors,  and  with  clear  wings.  The  nymphs  burrow  into  the  sand  or 
vegetable  silt  on  the  bottom  of  shallow  places.  Thus  buried,  with  only 
the  top  of  the  eyes  and  tip  of  the  abdomen  showing,  they  remain  motionless 
for  a  long  time,  if  prey  does  not  come  near.  "In  a  dish  of  sand  on  my  table," 
says  Needham,  "I  have  had  a  nymph  remain  without  change  of  position 
for  weeks,  no  food  being  offered  it.  Let  any  little  insect  walk  or  swim  near 
the  nymph's  head,  and  a  hidden  labium  springs  from  the  sand  with  a  mighty 
sweep  and  clutches  it."  The  imagoes  are  strong  flyers  and  have  the  habit 
of  flying  back  and  forth,  as  on  a  regular  beat,  over  some  small,  clear  stream. 

The  family  Gomphidae  includes  six  genera,  comprising  about  fifty  species 
in  our  country.  They  are  mostly  large  forms,  clear-winged  and  with  bodies 
striped  with  black  and  green  or  yellow.  They  are  readily  distinguished 
by  the  wide  separation  of  the  rather  small  eyes.  The  abdomen  is  stiff  and 
spike-like.  The  eggs,  held  in  a  scanty  envelope  of  gelatin,  are  deposited 
by  the  repeated  descent  of  the  flying  female  to  the  water  of  a  clear  pond 
or  flowing  stream,  the  tip  of  the  abdomen  first  striking  the  surface.  The 
gelatin  dissolves  and  the  eggs,  scattering,  sink  to  the  bottom  and  become 
hidden  in  the  silt.  The  nymphs  are  active  burrowers,  capturing  their  prey 
either  on  or  beneath  the  surface  of  the  bottom  silt.  The  adults  often  alight 
on  foliage,  or  on  the  surface  of  some  log  stretching  across  a  stream,  or  on 
the  bare  soil  of  a  path  or  roadway.  They  do  not  fly  about  in  apparent 
sportiveness  as  the  skimmers  (Libellulidoe,  p.  95)  do,  nor,  like  the  skim- 
mers, perch  atop  a  slender  twig.  June  is  the  best  month  in  the  East  for 
these  dragon-flies.  The  principal  genus  of  the  family  is  Gomphus,  which 
includes  one-third  of  all  our  Gomphidae.  Of  these  Gomphus  exilis  is 
probably  the  most  common  one  in  the  Northeastern  States.  Its  head  is  pale 
green,  thorax  brownish  with  two  oblique  green  bands  on  each  side,  and 
abdomen  blackish  brown  with  a  basal  green  spot  or  band  on  the  back 
of  each  segment.  The  nymphs  transform  at  the  very  edge  of  the  water^ 
seldom  crawling  more  than  an  inch  or  two  above  it.  Hagenius  brevistyliis 
is  a  large  black-and-yellow  species  common  in  the  East,  South,  and  Middle 
West.     The  nymph  has  an  unusually  wide,  flattened  body. 

The  /Eschnidse  include  our  largest,  swiftest,  and  most  voracious  dragon- 
flies.  Various  species  are  flying  through  the  whole  season  from  early  spring 
to  late  summer.  Some  roam  far  from  water,  being  found  over  dry  fields 
and  roadways,  and  even  in  houses.  Some  forms  fly  until  late  in  the  even- 
ing, making  life  a  burden  for  the  mosquitoes  gathering  for  their  night's 
singing  and  feasting.  The  eggs  are  thrust  into  the  stems  of  aquatic  plants, 
in  floating  timbers,  in  the  wood  of  piers,  etc.,  at  or  near  the  surface  of  the 


Dragon-flies  and  Damsel-flies  93 

water.  The  nymphs  are  slender,  clean  creatures,  with  smooth  bodies  pat- 
terned with  green  and  brown,  and  very  active,  strong,  and  brave.  They 
climb  among  green  plants  and  roots  or  submerged  driftwood  along  the  border 
of  open  water  or  the  edge  of  a  current.  The  imagoes  of  this  family  can  be 
recognized  by  the  meeting  of  the  eyes  all  along  the  top  of  the  head.  The 
wings  are  long,  broad,  and  clear,  and  the  body-colors  are  mostly  bright  blue 
and  green.  The  family  is  represented  in  the  United  States  by  about  twenty-five 
species,  belonging  to  six  genera.  Anax  Junius,  one  of  the  commonest  dragon- 
flies  all  over  the  United  States,  and  found  also  from  Alaska  to  Costa  Rica, 
in  China,  Siberia,  and  in  various  islands  of  the  Pacific,  notably  the  Hawaiian 
group,  is  the  most  inveterate  enemy  that  the  mosquito  has.  It  is  conspicu- 
ously on  the  wing  from  early  spring  to 
late  fall,  flying  from  daylight  to  dark, 
and  doing  untold  good  by  its  ceaseless 
warfare  on  the  mosquito  hosts.  It 
can  be  recognized  by  its  clear  wings, 

large  size  (wings  over  two  inches  long), 

,  ,    .   ,                    ,                   ,  ,        ,     ,  Fig.   124a.                      Fig.   1240. 
and  bright-green  thorax  and  head,  the 

,   ^.        ,         .                  ,1                      r        .  Fig.  124a. — Top  of  head,  showing  charac- 

latter    bearmg    on    the  upper   front  a  ^^^.^^  mark   in  front  of  eyes,  of  Anax 

round  black  spot  surrounded  by  yellow,      Junius.    (Enlarged.) 

the   yellow   encircled  by   a   dark-blue  Fig.  1 24^. -Top  of  head,  showing  charac- 
•'  •'  teristic  mark  in  front  of  eyes,  of  ALSckna 

ring  (Fig.  124(7).     A  still  larger  member      constricta.    (Enlarged.) 

of   this   family    is   the   great    "hero" 

dragon-fly,  Epiccschna  heros,  which  is  like  Anax  Junius  in  general  appear- 
ance, but  has  wings  two  and  one-half  inches  long,  and  abdomen  nearly  three 
inches  long.  It  has  a  black  T  spot  on  the  upper  face,  instead  of  a  round 
one.  Another  similar,  widely  distributed  and  common  form  is  .Eschna 
constricta,  about  the  size  of  Afiax  Junius,  reddish  brown  marked  with  bright 
green,  and  with  a  black  T  spot  on  the  upper  front  of  face  (Fig.  124^).  The 
males  have  the  abdomen  marked  with  blue,  with  little  or  no  green,  while 
the  females  have  but  little  blue  or  none  at  all. 

The  members  of  the  family  Libellulidai  are  called  "skimmers."  They 
may  be  seen  continually  hovering  over  the  surface  of  still  water,  or  swiftly 
foraging  over  fields.  Many  of  them  have  the  wings  strongly  marked  with 
large  black  or  brown  or  milk-white  blotches,  and  the  abdomen  is  often 
covered  with  a  whitish  powder  or  "bloom."  They  outnumber  all  the  other 
true  dragon-flies  in  point  of  species,  and  except  for  Anax  Junius,  ^Eschna 
constricta,  and  perhaps  the  giant  hero  dragon-fly,  include  the  most  familiar 
and  wide-spread  members  of  the  order.  One  of  the  best  known  and  most 
beautiful  of  the  skimmers  is  the  pond-loving  "ten-spot,"  Libellula  pulchella 
(Fig.  125),  found  all  over  the  country.  Each  of  its  wings  has  a  longitudinal 
basal  blotch,  a  median  blotch  (at  the  nodus),  and  an  apical  blotch  of  black- 


94 


Dragon-flies  and  Damsel-flies 


ish  brown.     The  males  have  the  space  between  these  blotches  milky  white. 
In  old  individuals  the  abdomen  has  a  stron^  whitish  bloom.     Other  familiar 


Fig.   125. — The  ten-spot  dragon-fly,  Libellula  pulchella.     (After  Needham;    nat.  size.) 

and  well-marked  species  of  Libellula  are  L.  hasalis,  with  blackish-brown  body 
and  with  the  basal  third  to  half  of  the  wings  dark  brown  or  black  and  the 
rest  of  the  wing  clear,  or  in  the  old  males  chalky  white  out  as  far  as  the 


Fig.   126. — Libellula  semi-Jasciala.     (After  Needham;    natural  size.) 


pterostigma,  and  in  the  females  with  brownish  apices;   L.  qnadrimaculata, 
with   olive  or  yellowish    body  marked  with  black,  front  wings  with  more 


Dragon-flies  and  Damsel-flies 


95 


or  less  yellowish  at  base  and  along  the  front  margin,  and  a  small  fuscous 
nodal  spot,  hind  wings  with  a  yellowish-black  triangular  basal  spot  and 
fuscous  nodal  spot;    and  L.  semi-jasciata,  whose  complex  wing-markings  are 


Fig.  127. 


-The  water-prince,  Epicordnlia  princeps,  female. 
(After  Needham;    natural  size.) 


shown  in  Fig.  126.  Tramea  is  a  genus  of  large  swift  dragon-flies  whose 
hind  wings  have  the  base  expanded  and  conspicuously  colored.  Tramea 
laceyata  is  a  familiar  species.     The  water-prince,  Epicordulia  princeps  (Fig. 


5. — The  amber  wing,  Perithemis  domitia,  male  at  left,  female  at  right. 
(After  Needham;  natural  size.) 


127),  is  a  common  large  dragon-fly,  but  one  hard  to  capture  because  of  its 
fine  flight.  The  wings  show  a  basal  patch,  often  nearly  wanting  on  the 
front  pair,  a  patch  at  the  nodus,  and  a  black  apex.     It  likes  "ponds  or  slug- 


96 


Dragon-flies  and  Damsel-flies 


gish  streams  with  muddy  reed-grown  banks,  and  seems  absolutely  tireless 
in  flight;    very  rarely  indeed  is  one  seen  resting."     One  of  the  smallest  of 


Fig.  129. — The  wind  sprite.  Celithemis  eponina.     (After  Needham;    natural  size.) 


Fig.   iT,o.—Tetragoneuria  epinosa,   female.     (After  Needham;    natural  size.) 

the  true  dragon-flies  is  the  amber  wing,  Perithemis  domitia  (Fig.  128).     The 
wings  are  clear  amber,  unmarked  in  the  male,  but  richly  spotted  with  dark 


Dragon-flies  and  Damsel-flies 


97 


brown  in  the  female.  It  has  a  slow  hovering  flight  and  often  rests  on  the 
tips  of  erect  reeds  with  wings  held  perfectly  horizontal.  It  is  only  on  wing 
in  quiet,  warm  sunshine;  clouds  or  cold  breezes  send  them  quickly  into 
hiding.  Among  the  familiar  Libellulids  with  unblotched  wings  is  Meso- 
themis  simplicicollis,  an  abundant  species  east  of  the  Rockies.  The 
females  and  young  males  have  head,  thorax,  and  front  half  of  abdomen 
green,  the  hinder  half  blackish  brown.  In  old  males  the  body  becomes 
grayish  blue  with  a  whitish  bloom.  WiUiamson  says  that  sometimes  two 
males  will  flutter  motionless,  one  a  few  inches  in  front  of  the  other,  when 
suddenly  the  rear  one  will  rise  and  pass  over  the  other,  which  at  the  same 
time  moves  in  a  curve  downwards,  backwards,  and  then  upwards,  so  that 
the  former  position  of  the  two  is  just  reversed.*'  These  motions  kept  up 


<s 


Fig.  131. — The  whitetail,  Plathemis  lydia.     (After  Needham;    natural  size.) 


with  rapidity  and  regularity  give  the  observer  the  impression  of  two  inter- 
secting circles  which  roll  along  near  the  surface  of  the  water. 

The  whitetail,  Plathemis  lydia  (Fig.  131),  resembles  the  ten-spot,  but 
is  one-fourth  smaller.  In  the  males  also  the  apex  of  the  wings  is  usually 
clear,  not  brown.  The  whitetail  rather  likes  slow-flowing  brooks  and 
open  ditches.  When  alight  it  has  the  habit  of  setting  its  wings  aslant  down- 
ward and  forward  with  a  succession  of  jerks.  Needham  thinks  that  the 
powdery  whiteness  of  the  body  of  the  old  males  (in  females  and  young  males 
the  body  is  brown  marked  with  yellow)  must  render  it  more  easily  seen  by 
its  enemies,  the  king-birds  and  others,  and  thus  be  a  disadvantage  in  the 
struggle  for  existence.     He  says,  indeed,  that  the  whitest  ones  avoid  rest- 


98 


Dragon-flies  and  Damsel-flies 


ing-places  over  a  dark  background  and  settle  oftenest  on  white  sticks,  on 
bleached  stumps,  or  on  light-colored  earth.  Very  frequently  one  will  alight 
on  a  white  insect-net  when  it  is  laid  down,  or  even  when  still  held  in  the 
hand. 


CHAPTER   VII 


THE  TERMITES,  OR   WHITE  ANTS  (Order  Isoptera) 

NCE  when  camping  in  the  King's  River 
Canon,  one  of  the  great  vertical -walled,  flat- 
floored  canons  of  the  Sierra  Nevada,  the 
boldest  axeman  of  our  party  attacked  the 
fallen  trunk  of  a  once  towering  yellow  pine. 
The  practical  outcome  of  this  attack  was 
a  sufficient  supply  of  firewood  for  the 
cook's  stone-built  stove,  but  the  great  log 
yielded  better  things  than  chips  and  chunks. 
A  few  blows  showed  it  to  be  the  home  of 
a  thriving  colony  of  the  largest  of  the 
American  termites  {Termopsis  angusticollis),  and  the  thousands  of  indi- 
viduals in  this  insect  household  were  objects  of  interested  observation 
the  summer  through.  We  had  heard  of  the  rarity  of  white-ant  queens  in 
collections,  and  saw  in  this  isolated  and  apparently  easily  "rounded-up" 
community  an  easy  chance  to  discover  the  egg-laying  queen  of  this  species. 
But  we  had  not  reckoned  with  the  Californ'a  manner  of  tree-trunk:  it 
outlasted  the  summer's  chopping  by  two  score  feet  of  log  four  feet  thick. 
Yellow  pines  grow  250  feet  high  in  the  Sierran  forests.  But  although 
no  queen  was  found,  the  make-up  of  the  buried  termite  city  was  revealed. 
Galleries  and  chambers,  secret  ways  and  narrow  tunnels  were  all  ex- 
posed, and  the  interesting  communal  life  of  these  soft,  white-bodied  little 
creatures  was  made  partly  known  to  us. 

We  have  in  the  United  States  but  few  kinds  of  termites,  and  these 
much  less  interesting  in  habit  than  those  of  tropic  lands.  The  Amazons 
and  Central  Africa  are  the  centers  of  termite  life,  and  there,  because  of  their 
great  mounds,  their  serious  ravages  on  all  things  wooden,  and  their  enor- 
mous numbers,  the  white  ants  come  to  be  nearly  the  most  conspicuous  of 
the  insect  class.  Drummond's  account,  in  his  Tropical  Africa,  of  the  habits 
and  life  of  the  termites  of  the  Central  African  region  is  simply  a  tale  of 
marvels.  And  the  scattered  accounts  of  the  Brazilian  species  are  hardly 
less  wonderful.     In  the  South  Sea,  too,  the  termites  play  their  part  promi- 

99 


lOO 


The  Termites,  or  White  Ants 


nently.  I  have  seen  scores  of  cocoanut-palms  in  Samoa  with  their  trunks 
traced  over  from  ground  to  "feather-duster"  top,  a  hundred  feet  above,  by 
the  laboriously  builded  wood-pulp  tunnels  of  the  termites.  Each  of  these 
trees  carried  also  on  its  trunk,  about  four  feet  from  the  ground,  a  termite 
"shed"  or  depot  (Fig.  133),  a  foot  thick,  a  foot  wide,  and  two  feet  long, 
made,  like  the  tunnels,  of  pellets  of  chewed  wood,  glued  together  with  saliva, 
and  filled  with  crowded  galleries  and  chambers. 


Fig.   132.— Giant  hillock-nests  of  termites  in  tropical  Africa. 
(Adapted  from  Drummond.) 

But  in  the  United  States  our  few  species  make  their  communal  nests 
in  dead  and  dying  wood,  or  underground,  and  not  being  given  to  building 
great  dome-like  mound-nests,  or  making  covered  ways  up  all  the  trees  of 
a  great  forest  or  plantation,  are  not  as  conspicuous  as  their  tropical  cousins. 
Still,  few  observers  of  insects  have  failed  to  notice  the  Httle,  white,  wingless 
worker  termites,  scurrying  about  when  some  dead  stump  is  overturned  or 
split  open,  or  to  see  the  winged  males  and  females  swarming  out  of  the 
ground  some  sunny  day,  and,  after  a  brief  period  of  flight,  pursued  by  birds 
and  predaceous  insects,  setthng  to  earth  again  and  losing  their  wings. 

Before  proceeding  to  take  up  the  incompletely  known  life-history  of  our 
American  termites,  it  will  be  advisable  to  describe  their  general  structural 


The  Termites,  or  White  Ants 


lOI 


characters  and  the  composition  of  the  termite  communities.  The  body 
is  always  soft,  and  usually  milky-whitish  in  color,  though  sometimes  light 
or  dark  brown.  It  is  plump,  and  slightly  broader  than  thick.  The  abdo- 
men is  joined  broadly  to  the  thorax,  not  by  a  little  stem  or  peduncle  as  in 
the  ants,  with  which  insects  the  name  "white 
ants"  (unfortunately  too  long  and  widely 
used  to  be  done  away  with)  confuses  the 
termites  in  the  popular  mind.  The  termites 
not  only  are  not  ants,  but  are  neither  nearly 
related  to  them  nor  of  similar  structure. 
The  only  resemblances  between  the  two  forms 
exist  in  the  communal  life  and  in  the  com- 
position of  the  community  by  different  kinds 
ol'  individuals.  The  termites  are  either  blind 
or  have  only  simple  eyes,  have  slender  an- 
tennae which  look  as  if  made  up  of  tiny  beads 
strung  a-row,  and  have  biting  mouth-parts 
with  strong  jaws.  They  live  in  small  or  large 
communities,  the  individuals  in  any  one  of 
which,  although  belonging  to  the  same  species, 
being  of  from  three  to  eight  different  kinds 
or  castes.  That  is,  each  community  is  com- 
posed of  winged  and  wingless  individuals, 
the  winged  being  males  and  females,  while 
the  wingless  include  immature  individuals, 
sexually  incomplete  workers  and  soldiers, 
and  also  so-called  complemental  males  and 
females  which  are  individuals  able  to  help 
in  the  increase  of  the  community.  In  some 
species  there  are  no  workers,  while  in  others 
the  workers  may  be  of  two  kinds.  The 
soldiers  differ  from  all  the  others  in  ihe 
extraordinary  development  of  their  jaws, 
which  are  long  and  scissor-like;  their  heads 
are  also  much  enlarged  and  strongly  chitin- 
ized.  The  food  of  all  consists  mainly  of 
dead  wood,  and  of  curious  pellets  excreted 
from  the   intestine   and    called    "proctodeal 

food."  In  addition  some  species  attack  live  wood  and  even  soft  plants, 
and  cloth,  books,  papers,  etc.,  suffer  from  termite  ravages.  The  serious 
nature  of  their  attacks  on  wood  will  be  referred  to  later. 

The  development  of  the  termites  is  apparently  simple;    the  wingless 


Fig.  1.33.  —  Termite  shed  on 
cocoanut-palm  in  Samoa.  From 
the  shed  note  numerous  tunnels 
leading  down  to  the  ground,  in 
which  is  the  main  nest  of  the 
community;  a  few  tunnels  (only 
one  visible  in  the  picture)  lead 
up  the  trunk  of  the  tree.  (Pho- 
tograph by  the  author.) 


I02  The  Termites,  or  White  Ants 

workers  resemble  closely,  except  in  size,  the  just-hatched  young;  the  soldiers 
have  but  to  acquire  their  largeness  of  head  and  mandibles,  and  the  perfect 
insects  their  wings.  But  there  is  a  serious  complexity  in  termite  develop- 
ment in  that  at  hatching  all  the  young  are  alike,  and  the  different  castes 
or  kinds  of  individuals  become  differentiated  during  the  postembryonic 
development,  i.e.,  after  hatching.     This  matter  is  discussed  later. 

In  the  United  States  but  seven  species  of  this  order  of  insects  are  known. 
They  represent  three  genera,  which  may  be  distinguished  by  the  following 
table : 

Key  to  Genera. 

Simple   eyes   absent Termopsis. 

Simple  eyes  present. 

Tarsi  with  a  pulvillus  (little  pad)  between  the  claws;    prothorax  large  and 

oblong;     costal   (anterior)    area   of   the    wings   veined.  .Calotermes. 

Tarsi  without  terminal  pulvillus;    prothorax  cordate;    costal  area  of  wings 

without  veins Termes. 

Termopsis  and  Calotermes  each  include  two  species,  all  four  limited 
to  the  Pacific  Coast;  while  Termes  includes  three  species,  of  which  but  one, 
T.  flavipes,  is  found  in  the  northeastern  states.  This  has  been  introduced  from 
America  into  Europe,  and  is  well  known  there.  The  other  two  species,  and 
flavipes  also,  are  found  in  the  southwestern  and  Pacific  coast  states.  Thus 
Termes  flavipes  (Figs.  134  and  135)  is  the  only  representative  of  the  order  Isop- 
tera  which  can  be  observed  and  studied  in  the  East, 
but  it  is  so  commonly  distributed  that  the  student  of 
insects  in  almost  any  locality  can  find  its  communities. 
Despite  its  abundance,  however,  the  long  time  it  has 
been  known,  and  the  very  interesting  nature  of  its 
habits,  its  life-history  is  not  yet  wholly  worked  out. 
Fig.  134. — T.   flavi-  Jt  makes  its  nest  in  or  under  old  logs  and  stumps. 

Marlatf  natural  Sometimes  it  mines  a  nest  in  the  beams  and  rafters  of 
size  indicated  by  old  houses.  Howard  records  the  serious  injuries  done 
^"^■■'  to  a  handsome  private  residence  in  Baltimore  through 

the  mining  of  the  first-floor  timbers  by  the  hidden  termites.  Comstock 
has  found  them  in  the  southern  states  infesting  Uving  plants,  particularly 
orange-trees,  guava-bushes,  and  sugar-cane.  According  to  Comstock,  they 
attack  that  part  of  the  living  plant  which  is  at  or  just  below  the  surface 
of  the  ground.  In  the  case  of  pampas-grass  the  base  of  the  stalk  is 
hollowed;  with  woody  plants,  as  orange-trees  and  guava-bushes,  the  bark 
of  the  base  of  the  trunk  is  eaten,  and  frequently  the  tree  is  completely 
girdled;  with  sugar-cane  the  most  serious  injury  is  the  destruction  of  the 
seed-cane. 


The  Termites,  or  White  Ants 


103 


The  workers  of  T.  flavipes  (Fig.  134)  are,  when  full  grown,  about  ^  in, 
long,  while  the  soldiers  are  a  little  larger.  Both  of  these  castes  are  whitish. 
But  the  winged  males  (Fig.  135c)  and  females  which  come  from  the  nest 
and  swarm  in  the  air  in  late  spring  or  early  summer  are  chestnut-brown 
to  blackish  and  measure  about  I  in.  in  length.  The  four  wings  are  of  about 
equal  size,  and  when  the  insect  is  in  flight  expand  about  f  in.  When  at 
rest  they  lie  lengthwise  on  the  back,  projecting  beyond  the  tip  of  the  abdo- 
men. They  have  many  veins  and  are  pale  brown  in  color.  After  fl3'ing 
some  time  and  to  some  distance,  the  insects  alight  on  the  ground  and  shed 
their  wings  (Fig.  1356).  This  they  are  enabled  to  do  because  of  a  curious 
suture  or  line  of  weakness  running  across  each  wing  near  its  base.  All  the 
wing  beyond  this  suture  falls  oS,  leaving  each  now  wingless  male  or  female 
with  four  short  wing-stumps.  These  swarming  flights 
attract  the  birds.  Hagen  noted  fifteen  different  species 
of  birds  following  such  a  termite  flight  one  May-day  in 
Cambridge,  Mass.  "Besides  the  common  robins,  blue- 
birds, and  sparrows,"  he  says, 
"were  others  not  seen  before 
near  the  house.  The  birds 
caught  the  Termes  partly  in 
flight,  partly  on  the  ground, 
and  the  robins  were  finally 
so  gorged  in  appearance  that 
their  bills  stood  open!  " 

After  the  swarming  flight 
the  few  uneaten  males  and 
females  pair,  and  each  pair 
probably  founds  a  new  colony. 
Perhaps  some  of  the  pairs 
are   found    by    workers,   and 

taken  possession  of  as  the  royal  couple  for  a  new  community.  Exactly 
how  the  new  communities  of  flavipes  begin  is  not  known;  and  this  is 
an  excellent  opportunity  for  some  amateur  observer  to  distinguish  himself! 
The  egg-laying  queen  mother  of  a  flavipes  colony  also  has  yet  to  be 
discovered.  There  exist  in  many  species  of  termites  individuals  caUed  com- 
plemental  males  and  females.  These  are  forms  which,  in  case  of  the  loss 
of  the  real  king  or  queea,  can  develop  into  substitute  royalties.  Whether  such 
forms  exist  in  all  flavipes  colonies  does  not  seem  to  be  certainly  known. 
It  is  obvious  that  there  is  still  much  to  learn  about  the  interesting  life  of 
our  commonest  and  most  wide-spread  termite  species. 

Of  the  other  six  species  of  our  country,  afl  of  which  are  limited  to  the 
southern,   southwestern,  and  Pacific    states,    three,   representing  all  of  the 


Fig.  135a.  Fig.  135&. 

Fig.  135a. — T.  flavipes,  winged  male.     (After  Mar- 

latt;  natural  size  indicated  by  line.) 
Fig.    135&.  —  T.    flavipes,    complementary    queen. 

(After  Marlatt;  natural  size  indicated  by  line.) 


I04 


The  Termites,  or  White  Ants 


three  genera,  and  found  about  Stanford  University,  have  been  recently 
studied  by  Professor  Harold  Heath.  These  are  Termopsis  angusticollis, 
the  largest  of  the  American  termites,  Calotermes  castaneiis,  a  small  species  with 
brown-bodied  winged  forms,  and  Termes  lucijugus,  a  small  white  species 
common  in  Europe,  and  probably  brought  to  this  country  from  there.  The  fol- 
lowing account  of  Termopsis  angusticollis  is  based  chiefly  on  Heath's  *  studies. 
Termopsis  angusticollis  (Fig.  136)  is  the  largest  of  the  three  species  and 
the  most  abundant.  In  favorable  localities  colonies  may  be  found  in  almost 
every  stump  and  decaying  log,  and  even  in  dead  branches  on  otherwise  healthy 
trees.  The  galleries  are  made  in  the  deeper  portions  of  the  wood,  and 
usually  follow  the  grain.  The  colonies  with  the  primary  royal  pair  number 
usually  from  50  to  1000  individuals,  and  include  workers,  soldiers,  and  im- 
mature forms.  The  full-grown  workers  (Fig.  136)  are  f  in.  long,  the  soldiers 
(Fig.  136)  §  in.,  and  the  kings  and  queen  (Fig.  137)  a  little  less,  while  the 
wings  expand  i\  in.  After  the  death  of  the  primary  royalties  and  the 
development  of  several  substitute  royal  ^ 

forms  the  egg-laying  and  consequent 
increase  of  the  colony  are  much  more 
rapid.     Heath  counted  3221  individuals 


Fig.  136.  Fig.  157. 

Fig.    136. — The  large  termite  of  California,    Termopsis  angusticollis;    workers,   young, 

and  a  soldier.     (From  life;    natural  size.) 
Fig.  137. — A,  Dealated  primary  queen   of   Termopsis  angusticollis,  at  least  four  years 

old;   B,  complemental  queen.     (After  Heath;  three  times  natural  size.) 

in  one  colony,  in  which  were  also  thousands  of  eggs.  The  colony  which  we 
found  in  the  yellow-pine  log  in  the  King's  River  Cafion  certainly  num- 
bered many  thousands.  In  the  late  summer  or  early  autumn  the  nymphs 
(young  stage,  with  visible  wing-pads  of  perfect  insects)  that  have  developed 
during  the  year  moult,  the  operation  taking  from  ten  to  twenty  minutes, 
after  which  they  rest  for  two  hours,  while  the  wings  expand,  and  the 
body-wall  hardens  and  darkens;  they  take  flight  usually  about  dusk.     Some 

*  Heath,  H.,  The  Habits  of  California  Termites,  Biological  Bulletin,  vol.  4,   1902, 
PP-  47-63. 


The  Termites,  or  White  Ants  105 

soon  fall  to  the  ground,  but  others  may  fly  a  mile.  The  swarm  is  pursued 
by  birds  until  dark,  and  then  bats  take  a  turn  at  the  chase.  The  few  ter- 
mites that  escape  fly  from  tree  to  tree,  seeking  a  spot  of  decaying  wood. 
Heath  has  noted  them  dashing  against  door-knobs  and  nail-holes  and  against 
discolored  spots  on  trees  and  logs,  in  their  search  for  a  place  where  decay 
has  begun.  After  finding  a  suitable  spot  they  usually  shed  their  wings, 
not  by  biting  them  off,  as  said  of  some  species,  but  by  curving  the  abdomen 
until  it  rests  across  the  wings  of  one  side  and  then  moving  backwards 
and  sidewise  until  the  wing  tips  are  brought  against  some  obstruction, 
thus  causing  the  wings  to  buckle  and  break  along  the  transverse  suture  or 
line  of  weakness  at  the  base.  Sometimes  the  wings  are  not  shed  until  after 
the  nest  is  begun.  The  spot  is  usually  selected  by  the  female,  and  she  begins 
the  mining  and  does  most  of  it.  She  is  accompanied  by  one  or  more  males, 
who  may  occasionally  help  in  excavating.  When  the  burrow  is  large  enough 
for  two,  one  male  usually  crowds  in  beside  the  queen  and  fights  off  the  others. 
Sometimes  two  males  may  remain  with  the  queen;  Heath  thinks  that  such 
a  condition  may  last  for  a  year  or  more.  He  has  found  a  few  cases  where 
two,  three,  and  even  six  pairs  live  in  company.  The  actual  mating  does 
not  take  place,  probably,  until  some  time  after  the  nest  is  begun.  Heath 
has  notecT  pairing  from  a  week  to  a  fortnight  after  swarming. 

The  egg-laying  may  be  long  postponed.  Usually,  however,  about  two 
weeks  after  pairing  the  first  egg  is  laid,  and  from  one  to  six  are  deposited 
daily  until  the  total  number  amounts  to  from  fifteen  to  thirty.  When  the 
habitat  is  unusually  moist  the  royal  pair  may  remain  together  for  a  year 
without  producing  young.  Heath  has  found  the  Termopsis  royalties  to 
mate  readily  in  captivity,  and  has  had  more  than  500  pairs  of  primary  kings 
and  queens  in  excellent  condition  after  a  year  of  captivity.  Royal  pairs 
with  small  colonies  are  readily  found  by  stripping  oft'  the  bark  of  trees  from 
three  to  nine  months  after  the  swarming  period.  Heath  has  been  the  first 
to  find  actual  egg-laying  queen  termites  in  this  country. 

After  from  fifteen  to  thirty  eggs  are  laid  the  laying  ceases,  and  the 
parents  give  their  time  to  enlarging  the  nest  and  to  caring  for  the  eggs, 
which  are  kept  scrupulously  clean,  and  frequently  shifted  from  place  to 
place  in  the  nest.  The  young  are  all  alike  when  first  hatched.  After  three 
moults,  one  of  them  appears  as  a  large-headed  individual,  and  after  three 
more  moults  develops  into  a  perfectly  formed  soldier,  although  little  more 
than  one-half  the  size  of  the  soldiers  in  old  communities.  Three  months 
later  another  soldier  appears,  larger  than  the  first,  and  later  others  still 
larger,  until  after  a  year  the  full-sized  form  appears.  The  first  workers, 
too,  are  smaller  than  the  later  ones.  Nymphs,  i.e.,  young  of  the  winged 
individuals,  do  not  appear  until  after  the  first  year,  so  that  the  swarm  of 
winged  individuals  cannot  leave  a  nest  until  the  end  of   the  second  year  of 


io6 


The  Termites,  or  White  Ants 


its  existence.  The  life  of  these  early,  undersized  individuals  is  short. 
They  disappear,  perhaps  are  killed,  when  the  full-sized  individuals  appear. 
These  latter,  both  workers  and  soldiers,  live  at  least  two  years  and  perhaps 
longer. 

The  primary  king  and  queen  hve  for  at  least  two  years,  and  almost  cer- 
tainly longer.  Heath  believes  he  has  evidence  of  five  years  of  life.  After 
the  death  of  the  royal  pair  from  natural  or  other  causes,  the  members  of 
the  orphaned  colony  develop  from  the  young  nymphs  from  ten  to  forty  sub- 
stitute royal  forms.  By  some  unknown  process,  perhaps  peculiar  feeding, 
these  selected  nymphs  are  quickly  brought  to  sexual  maturity,  and  the  queens 
begin  egg-laying.  As  they  are  fed  and  cleaned  by  the  workers,  their  only 
business  is  to  lay  eggs.  Heath  observed  some  of  the  larger  queens  to  lay 
from  seven  to  twelve  eggs  a  day  continuously.  In  exceptional  cases  a 
worker,  or  even  a  soldier,  may  be  developed  into  an  egg-laying  queen. 
One  may  also  occasionally  find  a  few  winged  soldiers. 

In  Africa  forty-nine  species  of  Termites  are  known  *  (Sjostedt),  and  it  is 
on  this  continent  that  "the  results  of  Termitid  economy  have  reached  their 
climax."  More  than  a  century  ago  an  exploring  Englishman,  Smeathman, 
startled  zoologists  with  his  account  of  the  marvelous  termite  communities 
of  West  Africa.  He  told  of  the  great  mound- 
nests  of  Termes  heUicosus,  twenty  feet  high,  and 
so  numerous  that  they  had  the  appearance  of 
native  villages  (Fig.  132).  The  soldiers  are  fifteen 
times  as  large  as  the  workers,  and  the  fertile 
queen  has  her  abdomen  so  enlarged  and  stretched 
by  the  thousands  of  eggs  forming  inside  that  it 
comes  to  be  "fifteen  hundred  or  two  thousand 
times  the  bulk  of  the  rest  of  her  body  and 
twenty  or  thirty  thousand  times  the  bulk  of  a  la- 
borer." He  describes  the  egg-laying  as  proceed- 
ing at  the  rate  "of  sixty  a  minute,  or  eighty  thou- 
sand and  upward  in  one  day  of  twenty-four 
hours."  In  the  South  Kensington  Museum  at 
London  there  is  such  a  prodigious  queen  resem- 
bling simply  a  cylindrical  whitish  sausage  four 
inches  long.  A  similar  specimen  is  to  be  found 
in  the  natural-history  museum  of  the  University 
of  Kansas. 
The  enormous  number  of  individuals  in  a  great  village  of  nests  cannot 


Fig.  138.  —  Worker  and 
queen  of  Termes  red- 
mani.  (After  Nassonow; 
natural  size.) 


*  Sjostedt,  Y.,  Monographie  der  Termiten   Afrikas,  Kongl.  Svenska,  Vetensk.    Ak. 
Handl.,  v.  34,  1900,  pp.  1-236,  Stockholm. 


The  Termites,  or  White  Ants  107 

even  be  imagined.  But  according  to  African  travelers  the  direct  results 
of  the  presence  of  such  a  population  are  very  apparent.  Drummond 
(Tropical  Africa,  1891)  writes:  "You  build  your  house,  perhaps,  and  for 
a  few  months  fancy  you  have  pitched  upon  the  one  solitary  site  in  the  coun- 
try where  there  are  no  white  ants.  But  one  day  suddenly  the  door-post 
totters,  and  lintel  and  rafters  come  down  together  with  a  crash.  You  look 
at  a  section  of  the  wrecked  timbers,  and  discover  that  the  whole  inside  is 
eaten  clean  away.  The  apparently  solid  logs  of  which  the  rest  of  the  house 
is  built  are  now  mere  cylinders  of  bark,  and  through  the  thickest  of  them 
you  could  push  your  little  finger.  Furniture,  tables,  chairs,  chests  of  drawers, 
everything  made  of  wood,  is  inevitably  attacked,  and  in  a  single  night  a 
strong  trunk  is  often  riddled  through  and  through,  and  turned  into  match- 
wood. There  is  no  limit,  in  fact,  to  the  depredation  of  these  insects,  and 
they  will  eat  books,  or  leather,  or  cloth,  or  anything;  and  in  many  parts  of 
Africa  I  believe  if  a  man  lay  down  to  sleep  with  a  wooden  leg  it  would  be 
a  heap  of  sawdust  in  the  morning!  So  much  feared  is  this  insect  now  that 
no  one  in  certain  parts  of  India  and  Africa  ever  attempts  to  travel  with  such 
a  thing  as  a  wooden  trunk.  On  the  Tanganyika  plateau  I  have  camped  on 
ground  which  was  as  hard  as  adamant,  and  as  innocent  of  white  ants  appar- 
ently as  the  pavement  of  St.  Paul's,  and  awakened  next  morning  to  find  a 
stout  wooden  box  almost  gnawed  to  pieces.  Leather  portmanteaus  share 
the  same  fate,  and  the  only  substances  which  seem  to  defy  the  marauders 
are  iron  and  tin." 

But  more  impressive  than  this  devastation  of  houses,  tables,  and  boxes  is  the 
sight  of  millions  of  trees  in  some  districts  plastered  over  with  tubes,  galleries, 
and  chambers  of  earth  due  to  the  amazing  toil  of  the  termites  in  their  search 
for  dead  or  dying  wood  for  food.  According  to  Drummond,  these  tunnels 
are  made  of  pellets  of  soil  brought  from  underground,  and  stuck  together 
with  sahva.  The  quantity  of  soil  thus  brought  above  ground  is  enormous 
and  Drummond  sees  in  this  phenomenon  a  result  very  similar  to  that  accom- 
plished by  earthworms  in  other  parts  of  the  world,  and  made  familiar  to 
us  by  Darwin,  namely,  a  natural  tillage  of  the  soil.  As  Drummond  says: 
"Instead  of  an  upper  crust,  moistened  to  a  paste  by  the  autumn  rains  and 
then  baked  hard  as  adamant  in  the  sun,  and  an  under  soil  hermetically  sealed 
from  the  air  and  light,  and  inaccessible  to  all  the  natural  manures  derived 
from  the  decomposition  of  organic  matters — these  two  layers  being  eter- 
nally fixed  in  their  relations  to  one  another — we  have  a  slow  and  continued 
transference  of  the  layers  always  taking  place.  Not  only  to  cover  their 
depredations,  but  to  dispose  of  the  earth  excavated  from  the  under- 
ground galleries,  the  termites  are  constantly  transporting  the  deeper 
and  exhausted  soils  to  the  surface.  Thus  there  is,  so  to  speak,  a  con- 
stant  circulation  of   earth  in  the  tropics,  a  ploughing  and  harrowing,  not 


io8  The  Termites,  or  White  Ants 

furrow  by  furrow  and  clod  by  clod,  but  pellet  by  pellet  and  grain  by 
grain." 

With  a  few  references  to  certain  special  conditions  and  problems  in  the 
termite  economy,  we  must  finish  our  consideration  of  these  highly  inter- 
esting insects.  Do  the  termite  individuals  of  a  community  communicate 
with  each  other,  or  is  the  whole  life  of  the  colony  so  inexorably  ruled  by 
instinct  that  each  individual  works  out  its  part  without  personal  reference 
to  any  other  individual,  although  with  actual  reference  to  all  the  others, 
that  is,  to  the  community  as  a  whole?  It  is  pretty  certain  that  termites  have 
a  means  of  communication  by  sounds.  The  existence  of  a  tympanal  audi- 
tory organ  in  the  tibiie  of  the  front  leg,  like  that  of  the  crickets  and  katy- 
dids, has  been  shown  by  Fritz  Miiller,  and  the  individuals  have  a  peculiar 
jerking  motion  which  seems  likely  to  be  connected  with  the  making  of 
sounds  by  stridulation,  sounds,  however,  that  are  not  audible  to  us. 

The  spread  of  termites  from  one  continent  to  another,  as  in  the  case  of 
Termes  flavipes  from  America  to  Europe,  and  Termes  lucijugus  from 
Europe  to  America,  can  be  easily  explained  by  involuntary  migration  in 
ships.  In  unpacking  several  cases  of  chemicals  received  from  Ger- 
many at  Stanford  University,  scores  of  termites  were  exposed  when  the 
wooden  boxes  were  broken  up.  The  insects,  mining  in  the  wood  of  the 
boxes,  had  protection,  food,  and  free  transportation  on  their  long  ocean 
journey  from  Hamburg  around  Cape  Horn  to  California! 

In  termite  nests  are  often  found  individuals  of  other  insect  orders.  So 
often  are  such  cases  noted,  and  so  many  are  the  kinds  of  strangers  likely 
to  be  present,  that  entomologists  recognize  a  special  sort  of  insect  economy 
which  they  term  termitophily,  or  love  of  termites!  The  strangers  seem  to 
be  tolerated  by  the  termites,  and  apparently  live  as  guests  or  conmensals. 
More  than  loo  species  of  insects  have  been  recorded  as  termitophiles.  This 
curious  guest-life  exists  on  even  a  much  larger  scale  in  the  nests  of  true 
ants,  in  which  connection  it  is  called  myrmecophily  (see  p.  552), 

The  most  important  problem,  and  one  whose  solution  will  require  much 
exact  observation  (and,  if  possible,  experimentation),  is  that  of  the  origin, 
or  causes  of  production,  of  the  different  castes  or  kinds  of  individuals  in 
the  termite  community.  It  has  been  determined  by  various  observers  that 
all  the  termites  of  a  community  are  apparently  alike  at  birth.  That  is, 
there  is  no  apparent  distinction  of  caste,  no  separation  into  workers,  soldiers, 
and  perfect  insects.  The  soldiers  and  workers  are  not,  as  was  formerly 
thought,  the  result  of  the  arrested  development  of  the  reproductive  organs. 
They  are  not  restricted  to  one  of  the  sexes.  If  then  it  is  not  arrested  develop- 
ment, or  sex,  or  embryonic  (hereditary)  differentiation,  what  is  the  causal 
factor?  Grassi,  an  Italian  student  of  the  termites,  thinks  that  it  is  food; 
that  the  feeding  of  the  young  with  food  variable  in  character  brings  about 


The  Termites,  or  White  Ants  109 

the  differentiation  of  individuals.  To  understand  this  claim  it  is  necessary 
to  attend  more  closely  to  the  feeding  habits.  The  food  of  termites  con- 
sists almost  exclusively,  as  has  already  been  said,  of  wood.  But  this  wood 
may  be. taken  directly  from  the  walls  of  the  burrow  or  secured  indirectly 
from  another  individual.  In  this  latter  case  it  consists  of  disjecta  of  undi- 
gested material,  which,  while  mostly  wood,  must  be  mixed  with  other  or- 
ganic material:  because  the  termites  keep  their  nests  clean  by  eating  their 
cast  skins  and  the  dead  bodies  of  other  individuals.  This  undigested  mate- 
rial is  called  proctodeal  food.  In  addition,  a  certain  amount  of  evidently 
very  different  matter  is  regurgitated  through  the  mouth  from  the  anterior 
part  of  the  alimentary  canal.  This  is  called  stomoda^al  food.  As  the  young 
receive  all  their  food  from  the  workers,  it  is  apparent  that  there  is  oppor- 
tunity for  a  choice,  on  the  part  of  the  nurses,  in  the  kind  of  food  given  the 
young.  And  it  is  presumed  by  Grassi  that  such  a  choice  is  made,  and  that 
it  results  in  the  differentiation  of  the  castes.  As  a  matter  of  fact,  such  a 
differentiation  of  individuals  is  accomplished  in  the  honey-bee  community 
by  feeding  those  larva?  which  the  workers  wish  to  make  fertile  queens  "royal 
jelly" — a  rich  food  regurgitated  through  the  mouth  from  the  anterior  part 
of  the  alimentary  canal.  This  is  done  for  the  queens  during  the  whole 
larval  life,  while  larvae  which  are  fed  royal  jelly  for  only  one  or  two  days, 
and  then  mixed  pollen  and  honey  for  the  rest  of  larval  life,  develop  into 
workers.  With  the  honey-bee,  however,  the  workers  are  to  be  looked  on 
as  probably  only  arrested  females.  But  in  the  case  of  Termopsis  angusti- 
coUis  Heath  has  experimented  by  feeding  members  of 
various  colonies,  both  with  and  without  primary  royal 
pairs,  "on  various  kinds  and  amounts  of  food — procto- 
deal food  dissected  from  workers,  or  in  other  cases  from 
royal  forms,  stomodeal  food  from  the  same  sources, 
sawdust  to  which  different  nutritious  ingredients  had 
been  added — but  in  spite  of  all  I  cannot,"  he  says, 
"feel  perfectly  sure  that  I  have  influenced  in  any  un- 
usual way  the  growth  of  a  single  individual." 

This  is  by  all  odds  the  most  important  and  interesting 
problem  in  termite  economy,  and  the  solver  of  it  will  do 
much  for  zoological  science. 

A  singular  and  primitive  family  of  small  insects,  the      p  ^     ,  . 

Embiida?,  of  doubtful  affinities,  is  represented  by  not  iexana.  (After 
more  than  twenty  hving  species,  of  which  but  four  Melander;  en- 
occur  in  this  country.  The  individuals  do  not  live  in 
communities  as  the  termites  do,  but  in  structural  characters  they  probably 
more  nearly  resemble  these  insects  than  any  others.  Fig.  139  illus- 
trates a  typical  Embiid.     This  species,  Embia  iexana,  is  about  one-quarter 


1 1  o  The  Termites,  or  White  Ants 

of  an  inch  long,  and  of  rufous  color.  It  was  described  from  a  few  specimens 
found  at  Austin,  Texas.  This  insect  seems  to  be  very  susceptible  to  differ- 
ing degrees  of  humidity,  and  specimens  were  visible  only  after  the  ground 
had  been  moistened  by  rains.  As  the  sun  dries  the  ground,  the  insects 
burrow  into  the  soil.  They  spin  small  silken  webs  in  which  they  live  singly. 
These  webs  are  tunnels  made  in  some  crevice  of  the  rock  which  shelters 
them,  or  are  spun  between  grains  of  soil.  They  are  an  inch  or  more  in 
length  and  closed  at  one  end,  and  probably  serve  simply  for  protection.  The 
spinning-organs  of  the  insect  are  located  in  its  fore  feet,  a  condition  unique 
among  animals.     The  food-habits  of  the  Embiids  are  not  yet  known. 


CHAPTER  VIII 


THE  BOOK-LICE  AND  BARK-LICE  (Order  Corrodentia) 
AND  THE  BITING  BIRD-LICE  (Order  Mallophaga) 

OMETIMES  in  taking  from  the  shelves  an  old 
book,  long  untouched,  there  may  be  seen,  on 
turning  its  leaves,  numerous  extremely  minute, 
pale-colored,  wingless  insects,  the  book-hce,  or 
dust-hce.  So  small  are  they,  indeed,  that  a 
reading-glass  or  hand-lens  will  be  needed  to  make 
out  anything  of  their  real  appearance.  They 
run  about  rather  swiftly  and  seek  to  conceal  their  soft,  defenceless  little 
bodies  somewhere  in  the  binding.  Under  the  lens  they  are  seen  to  have 
a  rather  broad,  flattened  body  (Fig.  140),  six  short  legs,  no  wings  (although 
sometimes  tiny  wing-pads  are  present),  long,  slender  antennae,  and  a  pair  of 
small  black  spots  on  the  head,  the  simple  eyes.  There  is  a  distinct  neck, 
the  head  being  free,  and  plainly  wider  than  the  prothorax.  The  abdomen 
is  nearly  oval  in  outline.  There  are  no  distinctive  markings  or  pronounced 
chitinization  of  the  soft  body-wall.  These  book-lice  can  be  found  else- 
where than  in  old  books;  they  feed  on  dry,  dead  organic  matter,  the 
paste  of  the  book-bindings  and  the  paper,  and  are  common  in  birds'  nests, 
where  they  feed  on  the  cast-off  feathers,  in  the  crevices  of  bark,  and  on 
old  splintered  fences,  where  they  feed  on  moulds  and  dead  lichens. 

Certain  other  insects  closely  related  to  the  book-lice  are  not  so  small  and 
simple,  however,  some  having  two  pairs  of  wings  and  a  plump,  rounded 
body  (Fig.  141);  these  look  much  like  plant-lice  (Aphids).  These  winged 
kinds  do  not  live  in  libraries,  moreover,  and  the  name  "book-lice"  is  a 
misnomer  for  them.  They  are  rarely  seen  by  persons  not  trained  entomolo- 
gists, and  indeed  are  not  at  all  familiar  to  professed  students  of  insects. 

The  life-history  of  these  obscure  insects  has  been  but  little  studied,  but  it 
is  of  a  simple  kind,  the  metamorphosis  being  incomplete,  and  in  the  case 
of  the  wingless  forms  certainly  very  slight.  The  young  of  the  wingless  forms 
"  greatly  resemble  the  old,  but  have  no  ocelli  or  wings,  and  sometimes  the 
tarsi  are  of  two  joints,  while  in  the  adult  they  have  three."  The  structure 
of  the  adults  presents  no  points  of  particular  interest  except  in  the  case  of 
the  mouth.  The  book-lice  have  biting  mouth-parts,  the  jaws  being  strong 
and  heavy  for  the  successful  mastication  of  the  hard  dry  food.   In  the  throat 


1 1  2         Book-lice  and  Bark-lice ;    Biting  Bird-lice 


there  is  a  peculiar  little  chitinized  structure,  which  may  be  called  the 
oesophageal  sclerite  (Fig.  145).  This  structure  is  situated  in  the  floor  of 
the  pharynx  (forward  end  of  the  oesophagus),  and  has  some  special  function 
in  connection  wfth  the  peculiar  food-habits.  It  was  first  described  by  Bur- 
gess, and  was  for  a  long  time  supposed  to  be  peculiar 
''J^T  }  to  the  book-lice  alone.  But,  in  a  study  of  the  mouth 
structure  of  the  biting  bird-lice  (Mallophaga) ,  I  found 
an  almost  identical  oesophageal  sclerite  in  thirteen  out 
of  the  twenty-two  genera  of  the  Mallophaga.  On 
.  ,,  the  basis  of  this  common  possession  of  a  curious 
and  undoubtedly  important  mouth  structure  by  the 
book-lice  and  the  bird-lice  (and  on  the  basis  of  other 
strong  similarities)  it  seems  certain  that  these  two 
groups  of  insects  have  a  common  ancestry  not  very 
remote,  and  probably  should  be  included  in  a  single 
Fig.  140. — A  wingless  order, 
book -louse,  Atropos  sp.  -pj^g  Q^der  Corrodentia  as  at  present  known  con- 
tains about  two  hundred  described  species,  scattered 
over  the  world.  The  largest  species  occur  in  Brazil,  and  have  an  ex- 
panse of  wing  of  nearly  an  inch.  Ceylon  and  the  Hawaiian  Islands  are 
said  by  Sharp  to  be. specially  rich  in  species. 

The  members  of  the  order  can  be  divided  into  two  families  as  follows: 

Wings   well  developed;  ocelli  present  (in  addition  to  compound  eyes). .  .PSOCID.E. 
Wings    wanting  or  present  as  small  scales  or  pads;  ocelli  absent  . — Atropid.^. 

The  winged  Corrodentia  or  Psocidae  (which  may  be  called  bark-lice  to 
distinguish   them   from   the   wingless   book-lice)   are  ^ 

too   rarely  seen   to   be   at   all   familiar.     They   may  /^-^^^ 

most  commonly  be  found  in  small  clusters  on  bark,  ^-' 

each  cluster  or  colony  being  covered  over  by  fine 
silken  threads  spun  from  the  mouth.  The  wings 
are  held   roof-shape   over  the   back  (Fig.  141),  and 

the    body    and    wings    are    usually  pale  smoky    in   ^^^     i4i._a   winged 
general  color.     The  small  white  eggs  are  laid  on  the       bark-louse.     (Thirteen 
surface  of  the  bark  in  small  patches,  and  in  a  cluster       ^^™^^  '^^^"'"^^  ^'^^-^ 
of  bark-lice,  individual  in  all  stages,  from  very  young  to  adult,  may  be  seen. 

Banks  gives  the  following  key  to  the  North  American  genera: 

The  techinal  terms  discoidal  cell  and  posterior  cell  may  be  understood  by  reference  to 
Fig.   142. 

1.  Wings  with  scales  and  long  hairs Amphientomum. 

Wings  without  hairs  and  scales,  hyaline 2. 

2.  Tarsi  3-jointed 3. 

Tarsi  2-jointed 4- 


Book-lice  and  Bark-lice;    Biting  Bird-lice        113 

3.  Discoidal  cell  closed Myopsocus. 

Discoidal  cell  open , .' Elipsocus. 

4.  Discoidal  cell  closed 5. 

Discoidal  cell  open 6.  2 

5.  Discoidal  cell  four-sided. Psocus.  t  ^.<;)>i'''ZI^^^^^--'^ "         ^^       >^\  «?" 

Discoidal  cell  five-sided. 

Amphigerontia. 

6.  Third  posterior  cell  elliptical. 

C.ECILIUS. 

Third  posterior  cell  elongated. 

PoLYPSOCUS  ^'*^'  ^4^' — Diagram  of   venation  of  a  Psocid. 
„,  .   ,         ,    .  11     .        ,         '      d,  discoidal  cell;   \a,  2a,  -la,  posterior  cells. 

Third  posterior  cell  absent.  ^^^^^^  g^^^^  -, 

Peripsocus. 
The  few  North  American  species  of  the  true  book-lice  or  Atropidae  are 
included  in  five  genera,  which  may  be  distinguished  as  follows: 

The  technical  terms,  hitherto  undefined,  used  in  the  following  table  are  the  following: 
squaincp,  wings  in  the  condition  of  small  scales  or  pads;    hyaline,  clear,  not  colored. 

1.  Meso-  and  metathorax  united,   no  wings Atropos. 

Meso-  and  metathorax  separate,  rudimentary  wings 2. 

2.  Wings  with   veins Dorypteryx. 

Wings  veinless,  in  form  of  squamte  or  tubercles 3. 

3.  Squamas   small,    hyaline Clothilla. 

Squamae  in  the  form  of  scars Lepinotus. 

Small  tubercles  in  the  place  of  squamas Hyperetes. 

The  genera  Atropos  and  Clothilla  were  named  for  two  of  the  three  Fates 
of  mythology,  and  a  third  genus  was  named  Lachesis  for  the  third  Fate,  but 
unfortunately  the  last  genus  was  not  a  valid  one,  so  the  book-lice  have  lost 
their  third  Fate,  and  by  the  rigid  laws  of  zoological  nomenclature  can  never 
regain  her!  The  few  species  of  these  two  Fate-named  genera  are  the  com- 
monest of  the  book-lice.  Atropos  divinatoria  is  the  species  usually 
found  in  books.  It  is  about  i  mm.  long,  is  grayish-white,  and  the  small 
eyes  show  as  distinct  black  specks  on  the  head.  It  does  not  limit  its  feeding 
to  the  paste  of  book-bindings,  but  does  much  damage  to  dried  insects  in 
collections.  To  this  insect  has  long  been  attributed  the  power  of  producing 
a  ticking  noise  known  as  the  "death-watch,"  but  McLachlan,  an  authority 
on  the  Corrodentia,  does  not  believe  that  this  minute  insect  "with  a  body 
so  soft  that  the  least  touch  annihilates  it  can  in  any  way  produce  a  noise 
sensible  to  human  ears."  A  small  beetle,  called  Anobium,  is  well  known 
to  make  such  a  ticking  (by  knocking  its  head  against  the  wood  of  door-casings, 
floors,  etc.,  in  which  it  lives)  and  probably  the  "death-watch"  is  always 
made  by  this  beetle. 

Bird-collectors  are  often  annoyed  by  small,  wingless,  flat-bodied,  swift- 
running  insects  which  sometimes  escape  from  the  feathers  of  bird  specimens 
to  the  hands  and  arms  of  the  collector.  Poultry-raisers  are  sometimes  more 
seriously  troubled  by  finding  them  so  abundant  on  their  fowls  as  to  do  con- 


114        Book-lice  and  Bark-lice;   Biting  Bird-lice 


siderable  injury.  They  are  called  bird-lice,  but  they  should  not  be  confused, 
because  of  this  name,  with  the  true  blood-sucking  lice  that  infest  many  kinds 
of  animals,  particularly  domestic  mammals  and  uncleanly  persons.  The 
biting  bird-lice  (Fig.  143),  constituting  the  order  Mallophaga,  never  suck 
blood,  but  feed  exclusively  on  bits  of  the  dry  feathers,  which  they  bite  off 
with  small  but  strong  and  sharp-edged  mandibles.  The  true  lice  have 
mouth-parts  fitted  for  piercing  and  sucking,  and 
constitute  one  of  the  numerous  families  of  the 
order  of  sucking  bugs,  Hemiptera  (see  p.  217). 

More  than  a  thousand  species  of  biting  bird- 
lice,  or  Mallophaga,  are  known,  of  which  about 
two  hundred  and  fifty  have  been  found  on  North 
American  birds.  Although  by  far  the  larger  num- 
ber of  Mallophaga  infest  birds,  numerous  species 
are  found  on  mammals.  On  these  hosts  the  insect 
feeds  on  the  hair  or  on  epidermal  scales.  On 
both  birds  and  mammals,  therefore,  the  food  con- 
sists of  dry  and  nearly  or  quite  dead  cuticular  sub- 
stances, and  never  of  blood  or  live  flesh.  Those 
species  of  Mallophaga  which  infest  birds  are  never 
found  on  mammals,  and  vice  versa. 

The  injury  done  to  the  hosts  by  these  parasites 
consists  not  in  the  character  of  the  food-habits,  but 
chiefly  in  the  irritation  of  the  skin  caused  by  the 
scratching  of  the  sharp-clawed  little  feet  of  the  insects 
in  their  migrations  over  the  body.  When,  as  hap- 
pens sometimes  in  poultry-yards  and  dovecotes, 
a  fowl  or  pigeon  is  infested  by  hundreds  of  these  active  little  pests,  the 
afflicted  bird  becomes  so  restless  and  excited  that  it  takes  too  little  food 
and  gets  too  little  rest  and  thus  grows  thin  and  weak.  The  dust-baths 
taken  by  fowls  and  other  birds  are  chiefly  to  get  rid  of  the  bird-lice.  The 
fine  dust,  getting  into  the  breathing-pores  (spiracles)  of  the  insects,  suffocates 
them.  So  that  the  best  remedies  for  these  pests  of  the  barn-yard  are  to 
see  that  the  fowls  have  plenty  of  dust  to  bathe  in,  and  also  to  keep 
thoroughly  clean  their  roosting-  and  breeding-places.  By  tightly  closing 
up  the  hen-house  and  burning  sulphur  inside  (the  fowls,  it  is  hardly  necessary 
to  say,  first  being  excluded)  most  of  the  infesting  parasites  can  be  killed. 

The  life-history  of  the  Mallophaga  is  very  simple.  The  small  elongate 
eggs  are  glued  separately  to  the  hair  or  feathers  of  the  host,  and  from  them 
young  soon  hatch  (Fig.  144,3),  which,  except  in  size  and,  to  some  degree,  in 
marking,  closely  resemble  the  parents.  These  young  begin  immediately  their 
hair  or  feather  diet,  grow  larger,  moult  a  few  times,  and  in  a  few  weeks  reach 


Fig.  143. — A  biting  bird- 
louse,  Nirmiis  prce- 
stans,  from  a  tern, 
Sterna  maxima.  (Pho- 
tomicrograph  by 
George  E.  Mitchell; 
natural  size, one-twelfth 
inch.) 


Book-lice  and  Bark-lice;   Biting  Bird-lice        115 


maturity.  There  is  never,  in  young  or  old,  any  sign  of  wings  or  wing-pads. 
The  body  is  flattened,  so  much  so  indeed  that  it  is  difficult  to  hold  a  live 
specimen  securely  between  thumb  and  finger-tip.  The  body-wall  is  strongly 
chitinized,  and  is  firm  and  smooth.  The  markings  are  often  very  distinct, 
and  sometimes  bizarre,  but  the  coloration  varies  only  from  white  to  black 
through  various  shades  of  pale  yellowish  brown,  tawny,  reddish  brown,  and 
blackish  brown.  The  antennae  are  short  and  in  one  suborder  (see  classifica- 
tion key)  are  wholly  concealed  in  pits  or  grooves  on  the  under  side  of  the 


Fig.  144. — Immature  and  adult  stages  of  the  biting  bird-louse,  Lipeuriis  forficidatiis, 
taken  from  a  pelican,  i,  adult  female;  2,  adult  male;  3,  very  young  stage;  4, 
older  immature  stage.     (Natural  size  of  adult  specimens   ^s  in.) 

flattened  head.     The  legs  are  strong,  and  each  foot  bears  two  claws.     These 
small  creatures  run  very  swiftly. 

Perhaps  the  oddest  thing  about  the  structure  of  the  Mallophaga  is  the 
presence  in  the  throat  of  the  curious  oesophageal  or  pharyngeal  sclerite 
already  referred  to  in  the  account  of  the  Corrodentia.  This  sclerite  is  a 
sort  of  bonnet-shaped  piece  (Fig.  145)  lying  in  the  lower  wall  of  the  throat 
and  seems  to  be  an  arrangement  for  starting  the  little  bitten-off  pieces  of 
feather  barbs  straight,  that  is,  lengthwise  down  the  oesophagus!  The  bark- 
lice  and  book-lice,  which  have  a  similar  oesophageal  sclerite,  also  bite  off 
and  swallow  small  bits  of  hard,  dry  organic  substance. 


I  1 6       Book-lice  and  Bark-lice  ;   Biting  Bird-lice 


The  most  interesting  thing  in  connection  with  the  Mallophaga,  excepting 
their  parasitic  life  and  strange  food-habits,  is  the  puzzHng  problem  of  their 
distribution.  The  problem  in  its  largest  phase  is  this:  the  species  of  Mal- 
lophaga are,  in  a  majority  of  cases,  peculiar  (so  far  as  recorded)  each  to  some 
one  host  species.  But  the  instances  are  many  where  a  single  parasite  species 
is  common  to  a  few  or  even  to  many  host  species.  How  does  this  condition 
of  commonness  to  several  hosts  come  to  exist? 

As  the  Mallophaga  are  wingless,  their  power  of  migration  from  bird  to 
bird  is  limited.     Moreover,  they  can  live  for  but  a  short  time  oiT  the  body 

of  a  warm-blooded  host.  After  a  bird  is 
shot,  the  Mallophaga  on  it  die  in  from 
two  hours  to  three  or  four  days:  in  rare 
cases  living  individuals  are  found  on  the 
drying  bird -skin  after  a  week.  Although 
the  parasites  in  a  badly  infested  hen-house 
will  be  seen  on  the  roosts  and  in  the  nests, 
in  Nature  the  insects  are  rarely  found  off 
the  host's  body.  On  such  a  likely  place 
as  an  ocean  rock  from  which  I  had  just 
frightened  hundreds  of  perching  pelicans, 
cormorants,  and  gulls  no  parasites  could 
be  found.  Practically  migration  must  be 
accomplished  while  the  bodies  of  the  hosts 

sclente,  lateral  aspect,  from  a  biting  _  . 

bird-louse,  Euryjnopetiis  taurus,  from  mating  and  nesting,  and  when  gregarious 
an  albatross.     (Greatly  magnified.)     |^jj.^g     ^^^^^     ^^    p^j-^j^     closely     together. 

Occasional    migration  might    occur  from  a    bird   of  prey  to    its    captured 
victim,  or  from  victim  to  hawk. 

The  general  character  of  the  cases  in  which  a  single  Mallophagan  species 
is  common  to  several  host-species  may  now  be  considered.  Docophoriis 
lari  has  been  found  on  thirteen  species  of  sea-gulls,  and  Nirmiis  lineolatiis 
on  nine.  Gulls  are  gregarious,  perching  "  together  on  large  food-masses 
and  on  ocean  rocks.  But  on  these  rocks  gulls  are  closely  associated  with 
other  coast  birds,  as  cormorants,  pelicans,  murres,  etc.  And  the  gull-para- 
sites might  have  opportunities  to  migrate  to  these  other  bird-species. 
Docophorus  iderodes  and  Trinoton  luridum  are  common  to  many  duck  species 
(each  has  been  collected  from  nine),  but  ducks  also  are  gregarious,  and  in 
addition  are  much  given  to  hybridizing.  But  a  parasite  may  be  common  to 
several  host-species  of  non-gregarious  habits.  Docophorus  platystomiis  is 
common  to  several  hawk-species,  D.  cursor  to  several  owl-species,  D.  excisus 
to  several  swallows,  D.  californiensis  to  several  woodpeckers,  and  Z).  com- 
munis to  several  passerine  birds.     In  the  other  genera  of  Mallophaga  are 


Fig. 


-Bonnet-shaped    pharyngeal 


Book-lice  and  Bark-lice;    Biting  Bird-lice        117 

similar  cases,  and  in  all  these  cases  it  is  hard  to  see  how  actual  migration 
of  the  parasite  from  host  to  host  of  different  species  could  take  place.  Indeed 
there  are  cases  in  which  such  migration  is  absolutely  impossible.  Of  the 
262  species  of  Mallophaga  taken  from  North  American  birds,  157  have 
been  described  as  new  species,  while  105  are  specifically  identical  with  Mal- 
lophaga originally  described  from  European  and  Asiatic  birds;  hosts,  that 
is,  not  only  of  different  species,  but  geographically  widely  separated  from 
the  North  American  hosts!  Eliminating  the  few  cases  of  importations  of 
Hving  European  birds  to  this  country,  and  the  few  species  of  cicumpolar 
range,  there  remain  to  be  accounted  for  about  100  cases  in  which  a  single 
species  of  Mallophaga  is  common  to  both  Old  World  and  New  World  hosts. 

It  will  have  been  noted  that  in  all  the  cases  above  mentioned  of  parasite 
species  common  to  several  North  American  host-species,  the  host-birds  are 
closely  allied  forms,  that  is,  species  of  the  same  genus  or  allied  genera. 
This  condition  holds  good  also  for  practically  all  of  the  cases  in  which  both 
European  and  American  hosts  have  a  common  parasite.  For  example, 
Docophorns  pertusus  is  common  to  the  European  coot  {Fulica  atra)  and 
the  American  coot  {Fulica  americana);  Nirmus  pileus  is  common  to  the 
European  avocet  {Reciirvirostra  avocetta),  and  to  the  American  avocet 
{Recurvirostra  amcricana) ;  Lipeurus  jorficulatus  is  common  to  the  European 
pelican  {Pelecanus  onocrotalus)  and  to  the  American  pelicans  (Pelecanus 
erythrorhynchus  and  P.  calif ornicus),  and  so  on  through  the  list.  From 
this  fact  of  near  relationship  of  hosts  in  all  the  cases  of  parasite  species  com- 
mon to  several  host-species  it  seems  almost  certain  that  this  common  occur- 
rence, under  circumstances  not  admitting  of  migration  of  the  parasites  from 
host  to  host,  is  due  to  the  persistence  of  the  parasite  species  unchanged  from 
the  time  of  the  common  ancestor  of  the  two  or  more  now  distinct  but  closely 
allied  bird-species.  In  ancient  times  geographical  races  arose  within  the  limits 
of  the  ancestral  host-species;  these  races  or  varieties  have  now  come  to  be  dis- 
tinct species,  distinguished  by  superficial  differences  in  color  and  mark- 
ings of  plumage,  etc.  But  the  parasites  of  the  ancient  hosts  have  remained 
unchanged;  the  plumage  as  food,  the  temperature  of  the  body,  practically 
the  whole  environment  of  the  insect,  have  remained  the  same;  there  has 
been  no  external  factor  at  work  tending  to  modify  the  parasite  species,  and 
it  exists  to-day  in  its  ancient  form,  common  to  the  newly  arisen  descendants 
of  the  ancient  host. 

To  classify  Mallophaga  the  following  keys  to  suborders,  families,  and 
genera  may  be  used.  In  these  keys  are  included  only  genera  which  have 
been  found  in  the  United  States.  Seven  other  genera  of  Mallophaga  are 
known. 

In  the  following  tables  the  following  technical  terms  are  used  which  have  not  been 
previously  defined:   clavate,  club-shaped;   capitate,  with  the  tip  swollen  like  a  ball;»  tra- 


1 1 8        Book-lice  and  Bark-lice  ;   Biting  Bird-lice 

hecula,  triangular  membranous  processes  projecting  laterally  from  the  head  and  situated 
one  in  front  of  each  antenna;  temples,  the  hinder  lateral  parts  of  the  head;  ocular  emar- 
gination,  a  bending  in  of  the  lateral  margins  of  the  head  just  in  front  of  the  eyes;  lahral 
lobes,  short  blunt  membranous  processes  projecting  laterally  from  near  the  front  angles 
of  the  head;  sternal  markings,  blackish  markings,  bars  or  spots,  on  the  ventral  aspect  of 
the  thorax. 

Key  to  Suborders  of  Mallophaga. 

With    short   slender   3-   or   5 -segmented,    exposed    antennae;     no   palpi;   mandibles 

vertical Ischnocera. 

With  short  clavate  or  capitate,  4-segmented  antennae  concealed  in  shallow  cavities 
on   under   side   of  head;     4-segmented   palpi;     mandibles   horizontal. 

Amblycer.'V. 
Key  to  Genera  of  the  Suborder  Ischnocera. 
A.      With  3-segmented  antennae;    tarsi  with  one  claw;    infesting  mammals  only  (family 

TrichodectidcE) Trichodectes. 

AA.  With   5-segmented  antennae;    tarsi   with  two  claws;    infesting  birds  only   (family 
Philopterida). 
B.      Antennas  alike  in  both  sexes. 

C.      Front  deeply  angularly  notched Akidoproctus. 

CC.  Front  convex,  truncate,  and  rarely  with  a  curving  emargination,  but  never 
angularly   notched. 
D.      Body  broad  and  short;    head  with  large  movable  trabeculae. 

E.      Forehead  with  a  broad,  transverse  membranous  flap,  project- 
ing beyond  lateral  margins  of  the  head  in  the  male,   barely 

projecting  in  the  female Giebelia. 

EE.  Without   such  membranous   flap Docophorus. 

DD.  Body  elongate,    narrow;     head   with   vers'-   small  or  no   trabeculae. 

NiRMUS. 

BB.  Antennae  differing  in  the  two  sexes. 

C.      Body  wide,  elongate  oval  to  suborbicular. 

D.      Temples  rounded;    tip  of  abdomen  with  shallow,  curving  emargina- 
tion;   antennae  with  no  appendage;    third  segment  unusually  long. 

EURYMETOPUS. 

DD.  Temples  usually  angulated;  tip  of  abdomen  convex,  rarely  angularly 
emarginated  with  two  points. 

E.      First   antennal   segment   of   male   large,    and   sometimes   with 
an    appendage;     third   segment    always    with    appendage. 

Goniodes. 
EE.  First    antennal    segment    of   male    large,    but    always    without 
appendage;    third  segment  without  appendage.  .Goniocotes. 
CC.  Body  elongate,   narrow,   sides  subparallel. 

D.      Antennae    and    legs    long;     a   semicircular    depression    in    front   of 

moutli LiPEURUS. 

DD.  Antennae  and  legs  short;    depression  in  front  of  mouth  narrow  and 
elongate,  e.xtending  as  a  furrow  to  the  anterior  margin  of  the  head. 

Oncophorus. 
Key  to  Genera  of  the  Suborder  Amblycera. 

A.      Tarsi  vrith  one  claw;  infesting  mammals  only  (family  Gyropidce) Gyropus. 

AA.  Tarsi  with  two  claws;    infesting  birds  only  (family  Liotheidce). 
B.      Ocular  emargination  distinct,  more  or  less  deep. 


Book-lice  and  Bark-lice;    Biting  Bird-lice        119 


C.      Forehead  evenly  rounded,  without  lateral  swellings;    antenna;  projecting 

slightly  beyond  border  of  the  head Colpocephalum. 

CC.  Forehead  with  strong  lateral  swellings. 

D.      Mesothorax  separated  from  metathorax  by  a  suture. ..  .Trinoton. 

DD.  Meso-  and  metathorax  fused;    no  suture L^mobothrium. 

BB.  Ocular  emargination  absent  or  very  slight. 

C.      Sides  of  the  head  straight  or  slightly  concave,  with  two  small  laterally 

projecting  labral  lobes Physostomum. 

CC.  Sides  of  the  head  sinuous;    forehead  without  labral  lobes. 

D.       Ocular  emargination  filled  by  a  strong  swelling;    sternal  markings 

forming  a  quadrilateral  without  median  blotches Nitzschia. 

DD.  Ocular  emargination  without  swelling,  hardly  apparent  or  entirely 
lacking;    median  blotches  on  sternum. 

E.  Very  large;  with  two-pointed  appendages  on  ventral  aspect 
of  hind  head;  anterior  coxje  with  very  long  lobe-like  append- 
ages   Ancistrona. 

EE.  Small  or  medium;   without  bi-partite  appendages  of  hind  head. 

Menopon. 

The  Mallophaga  most  likely  to  come  under  the  observation  of  people 
not  collectors  of  birds  are  the  species  which  infest  domestic  fowls  and  mam- 
mals, and  the  following  few  descriptions  and  figures  of  particular  species 
are  therefore  limited  to  such  kinds. 

The  most  notorious  member  of  the  order  is  the  common  chicken-louse, 
Menopon  pallidum  (Fig.  146).  It  is  of  a  pale  straw-yellow  color,  from 
I  mm.  (^ig-  in.)  to  1.5  mm. 
in  length,  and  is  an  un- 
usually swift  and  active 
little  pest.  Other  Mallo- 
phaga infesting  chickens 
are  Goniocotes  hologaster, 
recognized  by  its  squarish 
head  with  angulated 
temples,  and  Lipeiirus 
variabilis,  2  mm.  (y^g-  in.) 
long  and  slender,  with  dis- 
tinct black  markings  on 
the  otherwise  smooth, 
white  body. 

Ducks  are  infested  by 
several     species.      Com-  ^^^    ^^^  p^^    ^^^ 

mon  among  them    is    the    Fig.    146.— The  biting  chicken-louse,  Menopon  pallidum. 
little  Docophoriis  icterodes    _  (After  Piaget;    natural  size,    i  to  1.5  mm.) 

(Fig.  147),  I  mm.  (uV  i"-) 
long,  with  head  curiously 
expanded  and  rounded  in  front,  darkish-red  head,  and  thorax  with  darker 


icterodes.     (Natural  size  indicated  by  line.) 


I20       Book-lice  and  Bark-lice;  Biting  Bird-lice 


bands,  and  a  white  region  in  the  middle  of  the  abdomen.  Trinoton  luridiim 
is  another  common  duck-louse  unusually  large,  being  from  4  to  5  mm.  (5  in.) 
long  and  readily  distinguished  by  the  triangular 
head  with  lateral  swellings,  and  the  abdomen  with 
pronounced  blackish-brown  transverse  bands. 


Fig.  ISO. 


Fig. 


Fig.  152. 


Fig.  148. — A  biting  louse  of  pigeons,  Lipeurus  bacillus.     (Natural  size  indicated  by  line.) 

Fig.  149. — Biting  louse  of  the  dog,  Trichodedes  latus.  (After  Nitzsch;  natural  size, 
I  to  1.5  mm.) 

Fig.  150. — Biting  louse  of  the  horse,  Trichodcctes  parumpilosus,  male.  (After  Morse; 
natural  size  shown  by  line.) 

Fig.  151. — Biting  louse  of  cattle,  Trichodcctes  scalaris.  (After  Lugger;  natural  size,  1.5 
to  2  mm.) 

Fig.  152. — Biting  louse  of  fringilline  birds,  Docophorus  communis.  (Natural  size  in- 
dicated by  line.) 


Book-lice  and  Bark-lice;    Biting  Bird-lice        121 


Pigeons  are  almost  always  infested  by  a  long  and  very  slender  louse, 
Lipeuriis  baculus  (Fig.  148).  The  head  and  thorax  are  reddish  brown, 
while  the  abdomen  is  dusky  with  darker  segmental  blotches.  This  bird- 
louse  was  described  and  named  more  than  two  hundred  years  ago. 

All  of  the  species  infesting  domestic  mammals  belong  to  the  genus  Tricho- 
dectes.  Dogs  are  often  infested  by  Trichodectes  latus  (Fig.  149),  a  short, 
wide-bodied  species  about  i  mm.  long;  while  cats  are  less  often  infested  by 
T.  subrostratus,  distinguishable  by  the  rather  pointed  head  with  a  short, 
longitudinal  furrow  on  the  under  side.  Horses  and  ^4flonkeys  are  troubled 
by  two  or  three  species,  of  which  T.  pilosiis,  a  hairy  form  with  antenna?  rising 
near  the  front  of  the  head,  and  T.  pariim pilosiis  (Fig.  150),  a  broader-bodied 
form  with  head  larger  and  less  flatly  rounded  in  front,  are  most  common. 
Trichodectes  scalaris  (Fig.  151)  infests  cattle  the  world  over,  while  sheep 
and  goats  have  species  peculiar  to  themselves.  Comparatively  few  species 
of  Trichodectes  have  been  recorded 
from  wild  mammals,  but  this  is 
simply  because  they  have  not  been 
sought    with    care.     Species    have 


153-  Fig.  154. 

Fig.   153. — A  biting  louse  of  gulls,  Nirmus  felix,  male.     (Natural  size  indicated  by  line.) 
Fig.  154. — Giant  bird-louse  of  the  albatrosses,  Ancistrona  gigas,  male.     (Natural  size 
indicated  by  line.) 

been  found  on  the  bear,  raccoon,  fox,  coyote,  weasel,  gopher,  beaver,  deer, 
skunk,    and   porcupine.       Gyropus,  the   other  mammal-infesting  genus   of 


122       Book-lice  and  Bark-lice;   Biting  Bird-lice 

Mallophaga,  has  been  found  only  on  the  guinea-pig.  Washing  the  body  of 
the  infested  animal  with  kerosene  emulsion  (see  p.  190)  is  probably  the 
most  effective  remedy  for  biting  lice. 

Of  the  nearly  three  hundred  species  of  Mallophaga  which  I  have  recorded 
(Proc.  Nat.  Mus.,  v.  22,  1899,  pp.  39-100)  from  wild  North  American  birds, 
mention  may  be  made  of  the  largest,  Lcemobothnum  loomis,  taken  from  the 
Canada  goose;  of  Docophorus  communis  (Fig.  152),  the  most  abundant  and 
widely  distributed  parasite  of  perching  and  song  birds;  of  the  pretty  Nirmns 
jelix  (Fig.  153),  with  its  clean  white  body  and  sharply  marked  black  spots; 
of  the  fierce-looking  Lipeurus  ferox,  found  on  albatrosses;  and  of  Ancistrona 
gigas  (Fig.  154),  found  on  fulmars,  the  broadest  of  the  Mallophaga. 

As  there  are  nearly  one  thousand  different  species  of  North  American 
birds,  and  Mallophaga  have  been  taken  from  but  two  hundred  and  fifty  of 
them,  it  is  obvious  that  the  collector  and  student  of  these  parasites  has  a 
profitable  field  open  to  him. 


CHAPTER  IX 


THE  COCKROACHES,  CRICKETS,  LOCUSTS,  GRASS- 
HOPPERS, AND  KATYDIDS 

(Order  Orthoptera) 


do  not  shut  up  our  singing  insects  in  cages 
as  the  Japanese  do,  and  bring  them  into 
the  house  to  cheer  or  amuse  us,  but  we  do 
enjoy  them,  and  were  our  summer  and 
early  fall  days  and  nights  to  become  sud- 
denly silent  of  chirping  and  shrilling,  we 
should  realize  keenly  how  companionable 
crickets  and  grasshoppers  and  katydids 
had  been  for  us.  A  wholesome  blitheness 
and  vigor  and  ecstasy  of  living  rings  out 
in  the  swift  and  steadfast  song  of  most  of 
our  field  and  wood  insect  singers,  while 
the  cheeriness  of  the  cricket  on  the  hearth 
is  familiar  poetry  and  proverb. 

Almost  all  this  insect  music  comes  from  the  members  of  one  order,  the 
Orthoptera.  Indeed  there  is  but  one  famous  insect  maestro,  the  cicada  (of  the 
order  Hemiptera),  which  does  not  belong  to  the  group  of  crickets,  locusts,  green 
grasshoppers,  and  katydids.  Besides  being  singers,  too,  the  Orthoptera 
are  the  characteristic  leapers  of  the  insect  world;  crickets  and  locusts  easily 
surpass  the  world's  athletes  for  high  jumping  if  the  record  takes  into  account 
the  comparative  size  of  the  athletes.  And,  curiously,  the  singing  Orthoptera 
are  the  leaping  ones.  Of  the  six  families  composing  the  order,  three  include 
insects  which  do  not  sing  nor  leap,  while  the  other  three  are  made  up  of 
singers  and  leapers. 

As  one  tramps  the  roadways  or  dry  pastures  in  summer  and  autumn, 
the  steady  shriUing  of  the  locusts  on  the  ground,  or  their  sharp  "clacking" 
as  they  spring  into  air,  are  most  familiar  sounds.  When  you  ramble  through 
the  uncut  meadows  and  lush  low  grounds  the  still  shriller  singing  of  the 
slender-bodied,  thin-legged,  meadow  green  grasshopper  is  heard,  while 
in  the  orchards  and  woods  the  snowy  tree-crickets  and  broad-winged  katydids 

123 


I  24    Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 


keep  up 
offers  its 


the  chorus.  At  home,  in  house  and  garden,  the  domestic  cricket 
music  to  the  already  over-full  ears.  All  this  choiring  is  done  by 
singers  without  a  voice;  that  is,  without  the 
production  of  sound  from  the  throat  and 
mouth  by  means  of  vocal  cords  set  into  vi- 
bration by  air.  Insects  are  orchestral  per- 
formers, using  their  legs  and  wings,  for  the 
most  part,  to  make  their  music.  When  the  lo- 
cust sings  while  at  rest,  it  is  rasping  the  inner 
surface  of  the  broad  hind  thighs  across  the 
roughened  outer  surface  of  the  folded  fore 
wings;  when  it  "clacks"  in  the  air,  it  is  strik- 
ing the  front  margin  of  the  hind  wing  back 
and  forth  past  the  hinder  margin  of  the 
thickened  fore  wings.  When  the  cricket 
shrills  on  the  hearth,  or  anywhere  else,  he,  for 
only  the  male  crickets  have  the  musical  gift,  is  holding 
his  fore  wings  up  over  his  body  at  an  angle  with  it  of 
about  45°  and  is  rubbing  together  the  upper  surfaces  of 
the  basal  region  of  the  fore  wings,  which  are  specially 
modified  for  this  purpose.  The  tree-crickets,  katydids, 
and  meadow  green  grasshoppers  have,  in  the  males, 
the  same  general  sort  of  music-making  apparatus  as 
the  cricket,  and  sing  by  similarly  rasping  or  rubbing 
together    the  modified  parts  of  the  fore  wings.     This 


Fig.  155. — Longitudinal  section  through  head  and  neck  of  locust, 
showing  disposition  of  alimentary  canal,  brain,  and  sub- 
cesophageal  ganglion.     (After  Snodgrass;  much  enlarged.) 

music-making  by  rasping  is  called  stridulation,  and  for  the  most  part 
insect  stridulation  is  strictly  strident,  and  sounds  to  better  advantage  in  the 
field  than  it  would  from  caged  songsters  in  the  parlor. 


Cockroaches,  Locusts,  Grasshoppers,  and  Crickets    125 

All  the  Orthoptera  have  biting  mouth-parts,  and  bite  off  and  chew  their 
food,  which  is  usually  live  vegetable  matter,  especially  green  leaves, 
although  the  members  of  one  family  are  predaceous,  preying  on  other  insects, 
and  those  of  another  family  prefer  dried  vegetable  or  animal  matter.  The 
metamorphosis  is  incomplete,  the  young,  when  hatched,  resembling  the  parents 
except  for  small  size  and  lack  of  wings.  The  young  have  the  same  feeding 
habits  and  same  haunts  as  the  adults,  and  by  development  and  growth  the 


Fig.  156. — The  immature  stages  of  a  locust,  Melanoplus  jemur-rubrum.  a,  just  hatched, 
without  wing-pads;  h,  c,  d,  and  e  after  first,  second,  third,  and  fourth  rnoultings 
respectively,  showing  appearance  and  development  of  wings;  /,  adult,  with  fully 
developed  wings.     (After  Emerton.) 

wings  and  parental  stature  are  soon  acquired.  The  name  of  the  order  is 
derived  from  the  straight-margined  leathery  fore  wings,  or  elytra,  whose 
chief  function  is  to  cover  and  protect  the  larger  membranous  hind  wings 
on  which  the  flight  function  depends.  Among  the  leaping  Orthoptera  the 
hindmost  legs  are  very  large  and  long,  and  when  at  rest  or  in  walking  the 
"knee-joints"  of  these  legs  are  much  higher  than  the  back  of  the  insect. 

The  three  singing  and  leaping  families  are  the  AcridiidEe,  locusts  and 
grasshoppers  with  short  antenna;;    Locustidae,  meadow  green  grasshoppers 


126    Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 

and  katydids,  all  with  long  thread-like  antenna?;  and  Gryllidae,  the  crickets. 
The  three  silent  and  walking  or  running  families  are  the  Blattidae,  cock- 
roaches; Mantidae,  praying-horses  and  soothsayers;  and  Phasmidas,  walk- 
ing-sticks or  twig-insects.  These  families  can  be  distinguished  by  the  follow- 
ing table: 

KEY  TO  FAMILIES  OF  ORTHOPTERA. 

Non-leaping  and  mute;    hind   femora  closely   resembling  those  of  the  other  legs  and 
scarcely  stouter  or  longer  than  the  middle  femora;    tarsi  5-segmented;    ovipositor 
concealed. 
Body   oval,   depressed;    head    nearly  horizontal    and    nearly   or    quite    concealed    by 

the  flattish  shield-like  pronotum;   quickly  running (Cockroaches.)     Blattid.e. 

Body  elongate,  generally  narrow;   head  free,  often  with  constricted  neck;    pronotum 
elongate,    never   transverse;     slowly   walking. 
Fore  legs  spined  and  fitted  and  held  for  grasping;    antennae  usually  shorter  than 
body;    pronotum    usually   longer   than    any   other   body   segment;    anal   cerci 

jointed (Praying  Mantes.)     Mantid^. 

Fore  legs  not  fitted   for  grasping;    antennae   usually  longer  than  body;    pronotum 

short (Leaf -insects   and   Walking-sticks.)     Phasmid.i:. 

Leaping  and  usually  capable  of  stridulation;    hind  femora  stouter  or  longer,  or  both, 
than  the  other  femora;   the  hind  legs  enlarged,  for  leaping;   tarsi  4-  or  3-segmented; 
head  vertical;   ovipositor  usually  visible. 
Antenna;  much  shorter  than  the  body  (with  few  exceptions);  ocelli  three;  tarsi  3-seg- 
mented;   auditory  organs,  when  present,  situated  on  basal  abdominal  segment; 
ovipositor  composed  of  two  pairs  of  short,   strong,   slightly  curving  pieces. 

(Locusts.)       ACRIDIIDvE. 

Antennaj  much  longer  than  the  body,   delicately  tapering;    tarsi  3-  or  4-segmented; 
auditory  organs  usually  near  the  base  of  the  fore  tibise;    ovipositor  usually  pro- 
longed into  a  compressed  blade,  or  needle,  its  parts  compact. 
Tarsi  4-segmented;    ocelli  usually  absent;    ovipositor  usually  exserted  and  forming 
a  strongly  compressed,   usually  curving,   blade  with  tip  not  expanded. 

(The  long-horned  grasshoppers.)     Locustid^. 
Tarsi    3-segmented;     ocelli    variable;     ovipositor   usually    exserted   and    forming    a 
nearly  cylindrical  straight  needle,   the  tip  somewhat  expanded. 

(Crickets.)     Gryllid.e. 

Mrs.  Smith  takes  it  amiss  when  you  ask  permission  to  collect  "roaches" 
in  her  house,  and  will  prove  to  you  any  day  the  conspicuous  absence  of  these 
unwelcome  guests  in  the  scrubbed  and  spotless  pantry  and  kitchen.  But 
with  a  candle  go  stocking-footed  at  night  into  the  same  kitchen  and  you 
will  not  unlikely  find  "good  hunting."  Although  but  few  of  the  thousand 
different  kinds  of  cockroaches  known  in  the  world  are  to  be  found  in  the 
United  States,  these  few,  and  particularly  three  or  four  imported  foreigners 
among  them,  are  very  abundant,  and,  after  dark,  very  much  in  evidence  in 
their  favorite  habitat.  Their  chosen  abiding-place  is  in  kitchens,  pantries, 
laundries,  restaurants,  bakeshops,   etc.,    where    the    atmosphere    is    warm 


Cockroaches,  Locusts,  Grasshoppers,  and  Crickets     127 

and  humid  and  the  roach's  table  is  well  set  with  good  things.  Almost  any 
sort  of  dry  organic  matter  suits  their  taste;  bread,  crackers,  miscellaneous 
cold-lunch  delicacies,  the  paste  of  bookbindings  and  wall-paper,  leather, 
woolens,  and  even  their  own  egg-cases  and  cast  skins  making  up  the  dietary. 
The  fo'k'sel  and  galley  of  ships  are  the  roaches'  special  joy;  the  hotels  and 
restaurants  of  tropic  and  subtropic  lands  house  swarms  of  these  bill-evadint^ 
guests.  From  Mazatlan,  Mexico,  a  naturalist  sent  me  quarts  of  large  native 
American  roaches  (Periplaneki  americana),  which  he  readily  scooped  up 
from  his  bedroom  floor.  Ships  come  into  San  Francisco  from  their  long 
half-year  voyages  around  the  Horn  with  the  sailors  wearing  gloves  on  their 
hands  when  asleep  in  their  bunks  in  a  desperate  effort  to  save  their  finger- 
nails from  being  gnawed  off  by  the  hordes  of  roaches  which  infest  the 
whole  ship.  A  few  of  our  species  still  live  outside  under  stones  and  old 
logs,  but  most  of  them  have  learned  that  an  easier  life  awaits  them  in  the 
kitchen. 

The  roaches  compose  the  Orthopterous  family  Blattida^,  and  are  an 
ancient  and  persistent  insect  group.  In  Carboniferous  times,  before  flies, 
butterflies,  bees,  and  wasps  had  come  into  existence,  cockroaches  were 
the  dominant  insects.  The  body  in  all  is  flattened  and  slippery  with  the 
legs  adapted  for  quick  running,  so  that  the  insects  are  well  fitted  to  escape 
safely  into  narrow  cracks  and  crevices.  The  head  is  concealed  from  above 
by  the  expanded  shield-shaped  dorsal  wall  of  the  prothorax  (pronotum). 
Wings  are  present  in  most  species,  the  front  pair 
leathery  and  serving,  when  the  wings  are  folded,  to 
cover  and  protect  the  larger,  thin,  membranous 
hind  pair.  In  some  forms  the  females  are  wingless, 
and  the  indoor  habit  may  be  held  responsible  for 

the    lessened    usefulness  and    resultant  loss  of  the  ^^^-    ^S7- — £gg-case    of 
'-T'l-  ii-  i.  c^^   J   r       i-'i.-        1        1        cockroach.    (Three  times 

wmgs.      1  he  mouth-parts  are  fitted  tor  bitmg  hard      natural  size  ) 

dry  substances,  the  jaws  being  strong  and  toothed. 

The  eggs  are  laid  in  small  purse-like,  horny,  brown  cases  (Fig.  157),  which 

are  usually  carried  about  by  the  female  until  the  young  are  ready  to  issue. 

The  young  grow  slowly,  requiring  probably  about  a  year,  in  most  species, 

to  become  fully  developed.     From  the  beginning,  the  young  can  run  about 

and  take  care  of  themselves,  eating  the  same  kind  of  food  as  the  adults. 

They  moult  several  times  during  growth,  and  at  each  moult  the  wing-pads 

are  a  little  larger. 

There  are  four  common  species  of  cockroaches  found  in  dwellings  in  this 

country,  only  one  of  which  is  native.     This  is  the  large  American  roach, 

Periplaneta  americana,  about  i|  inches  long  (to  tip  of   folded  wings),  light 

brown  in  color,  and  with  the  wings  expanding  nearly  3  inches.     This  species 

is  abundant  in  the    middle   and  western  states,  having   gradually  extended 


128    Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 

its  range  north  from  its  native  region  in  Mexico  and  Central  America.  The 
Australian  roach,  Periplaneta  australasia,  resembles  P.  americana,  but  is 
darker  in  ground  color,  a  qusrter  of  an  inch  shorter,  and  has  a  conspicuous 
yellow  submarginal  band  running  around  the  shield-shaped  pronotum. 
Each  fore  wing  has  also  a  strong  yellow  tapering  bar  in  the  basal  part  of 
the  costal  region.  It  came  originally  from  the  Australian  Pacific  region, 
and  is  now  spread  widely  over  the  world,  being  common  in  this  country 
in  Florida  and  other  southern  states.  The  most  abundant  and  destruc- 
tive house-roach  in  the  eastern  states  is  the  small  German  cockroach, 
Ectohia  gennanica  (Fig.  158),  about  half  an  inch  long,  and  pale  yellowish 
brownish  with    a    pair  of   distinct   black  longitudinal  stripes  on   the  pro- 


Fig.  158.  Fig.  159.  Fig.   160. 

Fig.  158. — The  croton-bug,  or  German  cockroach,   Ectohia  gennanica.     (Twice  natural 

size.) 
Fig.   159. — The  black  beetle,  or  Oriental  cockroach,  Periplaneta  orientalis.     (One  and 

one-half  times  natural  size.) 
Fig.   160. — The  common  wood  cockroach,  Ischnoptera  pennsylvanica.     (After  Lugger; 

natural  size  indicated  by  line.) 


notum.  This  roach  is  often  called  croton-bug,  from  its  intimate  asso- 
ciation with  the  pipes  of  New  York  City's  Croton-water  system.  It  is  an 
importation  from  Europe,  where  it  is  especially  abundant  in  Germany.  Its 
real  nativity  is  unknown,  but  it  is  now  of  world-wide  di.stribution.  The 
fourth  species  is  the  black  or  Asiatic  roach,  or  black  beetle,  as  it  is  sometimes 
called,  Periplaneta  orientalis  (Fig.  159).  This  roach  is  about  one  inch 
long,  with  brownish-black  body;  in  the  female  the  wings  are  rudimentary, 
and  in  the  male  the  wings  when  folded  do  not  quite  reach  the  tip  of  the 
abdomen.  This  species  is  common  in  all  the  eastern  and  Mississippi 
Valley  states  and  extends  as  far  west  as  the  great  plains.  It  is  the 
commonest  cockroach  in  England  and  Europe.  The  native  outdoor  species 
most  familiar  in  this  country  is  the  common  wood-cockroach,  Ischnoptera 


Cockroaches,  Locusts,  Grasshoppers,  and  Crickets    129 

pennsylvanica  (Fig.  160),  with  long,  light-colored  wing-covers,  and  wings 
which  extend  considerably  beyond  the  tips  of  the  abdomen.  The  margin 
of  the  pronotum  is  light,  the  disk  being  dark,  and  the  front  margins 
(lateral  when  folded)  of  the  wing-covers  are  lighter  than  the  discal 
parts.  The  body  is  an  inch  long  and  rather  narrow  and  slender.  This 
species  is  common  in  the  woods  and  sometimes  comes  into  houses  in 
summer-time. 

In  the  southern  states  and  those  of  the  Mississippi  Valley  a  large  insect 
may  be  not  infrequently  seen  standing  motionless  in  a  corner  of  a  window, 
in  a  striking  attitude.  This  attitude  may  be  taken  as  one  of  hopeful  prayer, 
as  those  who  gave  the  name  praying-mantis  to  the  insect  seem  to  have  taken 
it,  or  one  of  self-confident  readiness  to  do  violent  work  with  those  upraised, 
sharply  spined,  and  very  willing  fore  feet.  This  is  the  way  the  house-flies 
rightfully  take  the  mantis's  attitude.  Watch  an  unwary  bluebottle  crawl  or 
buzz  into  the  fatal  corner.     Blundering  buzziness  is  finished  for  that  blue- 


FiG.   161. — The    praying-mantis,   Mantis  religiosa.       (After  Slingerland;    natural  size.) 

bottle;  and  the  first  course  of  a  square  meal  has  come  to  him  who  waits 
and  watches.  Other  names,  as  rearhorse,  camel-cricket,  and  soothsayer, 
have  been  given  the  mantis,  all  suggested  by  the  attitude  and  curious  body 
make-up  of  the  creature.  The  prothorax  is  long  and  stem-like,  the  head 
broader  than  long,  with  protuberant  eyes,  and  the  fore  legs  are  not  used 
for  locomotion,  but  are  large,  strongly  spined,  and  fitted  for  seizing  and  hold- 
ing the  prey.  The  wings  are  short  and  broad  and  usually  rather  leaf-like 
in  coloration  and  texture,  the  whole  insect  when  at  rest  resembling  somewhat 
a  part  of  the  plant  on  which  the  mantis  ordinarily  stands.  The  window-corner 
is  a  new  and  unnatural  locale  for  the  insects,  but  the  abundance  of  prey  here 
in  summer-time  makes  it  a  good  feeding-ground. 

The  family  Mantidc-e  includes  less  than  a  score  of  species  in  this  country, 
all  of  them  southern  in  range,  and  only  a  few  occurring  north  of  the  Rio 


130    Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 


Grande   and    Gulf   coast   regions.      All   the    species   are   carnivorous,    and 

undoubtedly  do  much  good  in  making  away  with  many  noxious  insects.     In 

1899   some   specimens   of   the   common   European   praying-mantis,   Mantis 

religiosa  (Fig.  161),  were  found  in  and 
near  Rochester,  N.  Y.  They  had 
probably  been  accidentally  imported 
into  this  country  in  nursery  stocks  from 
France.  As  this  species  seems  able 
to  live  farther  north  than  our  native 
species,  Professor  Slingerland  is  laud- 
ably trying  to  establish  it  in  our  coun- 
try. He  takes  care  of  a  colony,  and 
is  distributing  many  of  the  egg-cases 
over  the  entire  country.  All  the  man- 
tids  lay  their  eggs  in  curious  masses 
(Figs.  162  and  163),  covered  with  a 
quickly  drying  tough  mucus.  These 
egg-cases  are  attached  to  branches  and 
plant-stems  in  the  fall,  and  the  young 
hatch  in  the  following  summer  and 
soon  grow  (moulting  several  times 
and  developing  wings)  to  full  stature, 
which  for  our  most  common  native 
species,  Stagmomantis  Carolina,  is 
about  2^  inches  long. 

Slingerland    has    collected   a    num- 
ber of  the   old  accounts  of  the  Euro- 
pean mantis  which  are  of  interest  as  proofs  of  the  light  and  graceful  fancy 

of  some  of  the  early  author-naturalists. 

The  ancient  Greeks  gave  the  insects 

the  name  Mantis,  that  is,  ** prophet." 

Mouffet,  writing    over    five    hundred 

years   ago,   says:    "They   are     called 

Mantes,     that     is,    Joretellers,     either 

because  by  their  coming  (for  they  first 

of  all  appear)  they  do  show  the  spring 

to  be  at  hand,  so  Anacreon  the  poet 

sang;    or  else  they  foretell  death  and  Fig.    163. — Egg-case    of    praving-mantis, 

famine,    as  Cslius     the    Scoliast    of      ^^'""''    ''^TT'    "'"'   T""'  rST'"f 
'  ■^'^     ^^        arrangement  of  eggs  inside.       (Natural 

Theocritus  has  observed ;    or,    lastly,       size  ) 

because  it  always  holds  up  its  fore  feet  like  hands  praying  as  it  were,  after 

the  manner  of  their  Diviners,  who  in  that  gesture  did  pour  out  their  sup- 


FiG.  162. — Egg-cases  of  the  praying- 
m-antis,  Mantis  religiosa.  (After 
Slingerland;    natural  size.) 


Cockroaches,  Locusts,  Grasshoppers,  and  Crickets    i  3 1 


plications  to  their  Gods."  And  he  says  again:  "They  resemble  the  Diviners 
in  the  elevation  of  their  hands,  so  also  in  likeness  of  motion;  for  they  do  not 
sport  themselves  as  others  do,  nor  leap,  nor  play,  but  walking  softly,  they 
retain  their  modesty,  and  shewes  forth  a  kind  of  mature  gravity.  ...  So 
divine  a  creature  is  this  esteemed,  that  if  a  childe  aske  the  way  to  such  a 
place,  she  will  stretch  out  one  of  her  feet,  and  shew  him  the  right  way,  and 
seldome  or  never  misse."  Piso  in  his  works  states  that  mantids  "change  into 
a  green  and  tender  plant,  which  is  of  two 
hands'  breadth.  The  feet  are  fixed  into 
the  ground  first;  from  these,  when  neces- 
sary, humidity  is  attracted,  roots  grow  out 
and  strike  into  the  ground;  thus  they 
change  by  degrees,  and  in  a  short  time 
become  a  perfect  plant." 

Almost  everywhere  that  mantids  occur, 
strange  superstitions  are  held  concerning 
them.  Most  of  these  ascribe  some  degree 
of  sanctity  to  them,  and  to  kill  them 
maliciously  is  considered  sinful.  Cowan 
says  that  "the  Turks  and  other  Moslems 
have  been  much  impressed  by  the  actions 
of  the  common  Mantis  religiosa,  which 
greatly  resemble  some  of  their  own  attitudes 
of  prayer.  They  readily  recognize  intelli- 
gence and  pious  intentions  in  its  actions, 
and  accordingly  treat  it  with  respect  and 
attention,  not  indeed  as  in  itself  an  object 
of  reverence  or  superstition,  but  as  a  fel- 
low worshipper  of  God,  whom  they  believe 
that  all  creatures  praise  with  more  or  less 
consciousness  and  intelligence.  Other  su- 
perstitions with  respect  to  the  Mantis  are 
current:  when  it  kneels  it  sees  an  angel 
in  the  way,  or  hears  the  rustle  of  its  wings; 
when  it  alights  on  your  hand  you  are  about 
to  make  the  acquaintance  of  a  distin- 
guished person;  if  it  alights  on  your  head, 

a    great   honor  will    shortly  be    conferred  Fig.  164. — The  walking-stick,  Diaphe- 

H-.    ■    ■  ■  romera  jemorata. 

it  mjures  you  ni  any  way, 

which  it  does  but  seldom,  you  will  lose  a  valued  friend  by  calumny.     Never 

kill  a  Mantis,  as  it  bears  charm  against  evil."     Finally,  monkish  legends 

tell  us,  says  Slingerland,  that  St.  Francis  Xavier,  seeing  a  Mantis  moving 


132    Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 

along  in  its  solemn  way,  holding  up  its  two  fore  legs  as  in  the  act  of  devo- 
tion, desired  it  to  sing  the  praise  of  God,  whereupon  the  insect  carolled 
forth  a  fine  canticle! 

More  amazing  than  the  Mantids  for  modification  of  form  and  appear- 
ance away  from  the  usual  insect  type  are  the  members  of  the  family  Phas- 
midse.  The  only  representatives  of  this  family  in  the  United  States  are 
the  walking-sticks,  or  twig  insects  (Fig.  164),  of  which  half  a  dozen  genera, 
with  from  one  to  three  species  each,  have  been  recorded.  The  only  one 
of  these  genera  which  is  found  in  the  East  is  Diapheromera,  of  which  D. 
jemorata  is  the  common  species.  Our  other  Phasmids  are  found  in  the 
West  or  extreme  South.  All  of  our  species  are  wingless  and  are  generally 
sluggish  in  movement,  and  depend  for  protection  largely  on  their  amazingly 
faithful  resemblance  in  shape  and  color  to  twigs,  and  on  their  capacity  to 
emit  an  ill-smelling  fluid  from  certain  glands  on  their  prothorax.  Diaphero- 
mera jemorata  (Fig.  164)  feeds  on  the  leaves  of  oaks,  walnuts,  and  probably 
other  trees.  It  drops  its  hundred  seed-like  eggs  loosely  and  singly  on  the 
ground,  where  they  lie  through  the  winter,  hatching  irregularly  through 
the  following  summer.  Some  may  even  go  over  a  second  winter  before 
hatching.  Fernorata  may  be  either  brown  or  green;  so  it  frequents  dead 
or  leafless,  or  live  and  green-leaved  parts,  according  to  the  correspondence 
of  its  body  color  with  the  one  or  the  other  of  these  environments.  The  long, 
slender,  wingless  body,  the  thin,  long  legs  held  angularly,  and  the  harmonizing 
body  color,  all  serve  to  make  the  walking-stick  well-nigh  indistinguishable 
when  at  rest  on  the  twigs. 

In  tropic  and  subtropic  countries  the  Phasmids  are  numerous  (over  600 
species  are  known)  and  present  other  striking  resemblances  to  the  details 
of  their  habitual  environment.  A  conspicuous  and  perfect  example  of 
resemblance  is  the  green  leaf-insect  Phyllium  (PI.  XIII,  Fig.  2),  whose  wings, 
flattened  body,  and  expanded  plate-like  legs,  head,  and  prothorax,  all  bright 
green  and  flecked  irregularly  with  small  yellowish  spots,  like  those  made 
by  the  attacks  of  fungi  on  live  leaves,  combine  to  simulate  with  wonderful 
effect  a  green  leaf. 

Other  examples  of  such  protective  resemblance  and  a  discussion  of  the 
origin  and  significance  of  the  phenomenon  may  be  found  in  Chapter  XVII 
of  this  book. 

The  genera  of  Phasmidae  occurring  in  the  United  States  may  be  distin- 
guished by  the  following  key: 


Tibiae  with  a  groove  at  tip  to  receive  the  base  of  the  tarsi  when  bent  upon  them. 
Antennae  with  less  than  twenty  segments,   and  much  shorter  than  the  fore  femora. 

Bacillus. 


Cockroaches,  Locusts,  Grasshoppers,  and  Crickets    133 

Antcnnre  with  many  segments,  and  longer  than  the  fore  femora. 

Mcsothorax   twice   as   long   as   prothorax Anisomorpha. 

Mesothorax  no  longer  than  prothorax Tinema. 

Tibias  without  groove  at  tip,  as  above  described. 

Hind  femora  with  one  or  more  distinct  spines  on  the  median  line  of  the  under  side 

near  the  tip Di apheromera. 

Hind  femora  without  such  spines. 

Head,  especially  in  female,  with  a  pair  of  tubercles  or  ridges  on  the  front  between 

the  eyes Sermyle. 

Head  without  such  tubercle  or  ridges Bacunculus. 

■ 

One  day  in  early  summer  of  the  Centennial  Year  (1876)  the  people  all 
over  Kansas  might  have  been  seen  staring  hard  with  shaded  eyes  and  serious 
faces  up  towards  the  sun.  By  persistent  looking  one  could  see  high  in  the 
air  a  thin  silvery  white  shifting  cloud  or  haze  of  which  old  residents  sadly 
said,  "It's  them  again,  all  right."  Now  this  meant,  if  it  were  true,  that, 
far  from  being  all  right,  it  was  about  as  wrong  as  it  could  be  for  Kansas. 
"Them"  meant  the  hateful  Rocky  Mountain  locusts,  and  the  locusts  meant 
devastation  and  ruin  for  Kansas  crops  and  farmers.  In  1866  and  again 
in  1874  and  1875  the  locusts  had  come;  first  a  thin  silvery  cloud  high  over- 
head— sunlight  glancing  from  millions  of  thin  membranous  fluttering 
wings — and  then  a  swarming,  crawling,  leaping,  and  ever  and  always 
busily  eating  horde  of  locusts  over  all  the  green  things  of  the  land.  And 
the  old  residents  spoke  the  truth  in  that  summer  of  1876.  It  was  "them," 
uncounted  hosts  of  them,  and  only  such  patriotic  farmers  as  had  laid  by 
money  for  a  rainy  day  or  a  grasshopper  year  could  visit  the  Centennial 
Exposition. 

Not  all  locusts  are  migratory  or  appear  in  such  countless  swarms  as 
this  invader  from  the  high  plateau  of  the  northern  Rocky  Mountains.  In 
South  America  another  locust  species,  larger  than  ours,  has  similar  habits; 
having  its  permanent  breeding-grounds  on  the  great  plateau  at  the  eastern 
foot  of  the  Chilean  Andes  and  descending  almost  every  year  in  swarms  on 
the  great  wheat-fields  of  Argentina.  And  in  Algeria  and  Asia  Minor  occurs 
the  migratory  locust  of  the  Scriptures,  a  still  other  and  larger  species.  But 
of  the  500  (app.)  locust  species,  members  of  the  family  Acridiidae,  which 
are  known  in  the  United  States  but  three  or  four  can  be  fairly  called 
migratory,  and  of  these  the  Rocky  Mountain  locust,  Melanopliis  sprelus,  is 
the  most  conspicuous.  The  lesser  migratory  locust,  Melanopliis  atlanis, 
does  much  injury  in  New  England  and  other  eastern  states,  while  the 
pellucid  locust,  Camnula  pellncida,  is  a  migratory  species  that  often  does 
much  harm  in  CaHfornia  and  other  western  states.  Sometimes  large 
bodies  of  immature  wingless  individuals  of  the  large  species  Dissosteira 
longipennis,  abundant  on  the  plains  of  eastern  Colorado  and  western  Kansas 


134    Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 


will  move    slowly  on,  walking   and  hopping  for  many  miles,  eating  every 

green  weed  and  grass-blade  in  their  path,  but  this  is  only  a  limited  and 

local  sort  of  migration. 

Almost  all  the  Acridiidae,  despite  the  many  species  in  the  family,  are 

readily    recognizable    as    locusts 

or      grasshoppers  —  short-horned 

grasshoppers  they  may  be  called, 

to    distinguish     them    from    the 

meadow  green  grasshoppers  with 

long  thread-like  antennae — because 

of  their  general  similarity  in  ap- 

„         .       T        w       1.1  WW.    •        pearance  and    habit.     The   body 

Fig.    105. — Locust  from  lateral  aspect  (left  wings  f  •' 

removed),    showing    (ao.)    auditory    organ,  is  rather  robust,  the  head  is  set 
(Natural  size.)  ^,^1-]^  j^g  joj^g  g^^is  at  right  angles 

with  the  axis  of  the  body,  so  that  the  mouth  with  its  strong  biting  and 
crushing  jaws  is  directed  downwards  (Fig.  165);  the  antennae  are  never 
as  long  as  the  body  and  are  composed  of  not  more  than  twenty-five 
segments;  the  prothorax  is  covered  laterally  as  well  as  dorsally  by  its  large 
saddle-like  horny  pronotum,  which  projects  so  as  also  to  cover  and  protect 
from  the  sharp  grass-blades  the  soft  thin-walled  neck  and  the  equally 
thin-walled  suture  between  prothorax  and  mesothorax;  the  abdomen  is 
broadly  and  closely  joined  to  the  metathorax,  and 
in  the  female  ends  in  a  short  and  strong  ovipositor 
composed  of  four  horny  pointed  pieces;  the  hind 
legs  are  much  larger  than  the  others  and  fitted 
for  leaping,  and  the  fore  wings,  called  tegmina, 
are  narrow  and  straight-margined,  and  serve 
specially  to  cover  and  protect  the  much  larger 
thin  membranous  hind  wings,  which  are  plaited 
and  folded  like  a  fan  when  the  locust  is  at  rest. 

The  sounds  or  stridulation  of  locusts  are 
made  in  two  ways.  When  at  rest  certain  species 
draw  the  hind  legs  up  and  down  across  the  wing- 
covers  so  that  numerous  fine  little  ridges  on  the 

inner  surface  of  the  broad  femora  are  rasped  pj^^g^^Locust  impaled  on 
across  a  thickened  and  ridged  longitudinal  vein  thorn  by  shrike  (butcher- 
on  the  outer  surface  of  the  wing-covers.  When  ^^''^^-  (Natural  size.) 
in  flight  certain  locusts  rub  or  strike  together  the  upper  surface  of  the 
front  edge  of  the  hind  wings  and  the  under  surface  of  the  fore  wings 
or  tegmina.  This  produces  a  loud,  sharp  clacking  which  can  be  heard 
for   a    distance    of   several    rods.      The    loudest   "clacking"   of    this  kind 


Cockroaches,  Locusts,  Grasshoppers,  and  Crickets     135 

that  I  have  heard  is  made  by  a  species  of  Trimerotropis,  abundant  in 
the  beautiful  little  glacial  "parks"  of  the  Colorado  Rockies.  Locusts 
undoubtedly  make  sounds  to  be  heard  by  each  other,  and  it  is  not  difficult 
to  find  in  them — a  matter  of  more  difficulty  in  most  other  insects — certain 
organs  which  are  almost  certainly  auditory  organs,  or  ears.  On  the  outer 
faces  of  the  upper  part  of  the  first  abdominal  segment  is  a  pair  of  sub- 


FiG.    167. — The  red-legged  locust,   Melanoplus  jemiir-rubrum,   female. 
(After  Lugger;   natural  size  indicated  by  line.) 

circular  clear  window-like  spots  (Figs.  165  and  55).  These  are  thin  places 
in  the  body- wall  serving  as  tympana;  on  the  inner  face  of  each  is  a  small 
vesicle,  and  from  it  a  tiny  nerve  runs  to  a  small  auditory  ganglion  (nerve- 
center)  at  one  side  of  the  tympanum.  From  this  auditory  ganglion  a  nerve 
runs  to  the  large  ventral  ganglion  in  the  third  thoracic  segment.  Similar 
auditory  organs  are  found  in  the  other  singing  Orthoptera,  the  crickets  and 
katydids,  but  situated  in  the  front  legs  instead  of  on  the  back. 


136    Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 

The  life-history  of  all  our  locusts  is,  in  general  characteristics,  very  similar. 
The  eggs  are  deposited  in  oval  or  bean-shaped  packets  enclosed  in  a  glutin- 
ous substance.  They  are  usually  laid  just  below  the  surface  of  the  soil, 
but  in  some  cases  are  simply  pushed  to  the  ground  among  the  stems  of 
grasses,  while  a  few  locust-species  thrust  them  into  soft  wood.  The  strong, 
horny  ovipositor  at  the  tip  of  the  abdomen  is  worked  into  the  ground,  the 
four  pieces  separated,  and  the  eggs  and  covering  mucous  material  extruded. 
The  eggs  in  a  single  mass  number  from  twenty-five  to  one  hundred  and 
twenty-five,  varying  with  different  species,  and  the  females  of  some  species 
lay  several  masses.  The  different  species  also  select  different  times  and 
places  for  egg-laying,  some  ovipositing  in  the  fall  and  some  in  the  spring, 
while  some  select  hard,  gravelly,  or  sandy  spots  or  well-traveled  roads,  and 
others  choose  pastures  and  meadows  and  the  uncultivated  margins  of  irriga- 
tion-ditches. 

If  the  eggs  are  laid  in  the  fall,  the  more  usual  case,  they  do  not  hatch 
until  the  following  spring.  The  young  hoppers  are  of  course  wingless,  very 
small,  and  pale-colored,  but  they  have  the  general  body  make-up  of  their 
parents,  with  the  biting  mouth  and  long-leaping  hind  legs.  They  push 
their  way  above  ground  and  feed,  as  do  the  adults,  on  the  green  foliage  of 
grasses,  herbs,  or  trees,  and  in  two  or  three  months  become  full  grown  and 
mature,  having  moulted  five  or  six  times  during  this  growth  and  developed 
wings.  The  wings  begin  to  appear  as  minute  scale-like  projections  from 
the  posterior  margins  of  the  back  of  the  meso-  and  meta-thoracic  segments, 
and  with  each  moulting  are  notably  larger  and  more  wing-like  in  appear- 
ance. During  all  this  development  the  wing-pads  are  so  rotated  that  the 
hinder  wings  (always  underneath  the  fore  wings  in  the  adult  locust)  lie  out- 
side of  and  above  the  fore  wings  (Fig.  156). 

The  family  Acridiidae  includes  in  the  United  States  about  500  species, 
representing  107  genera.  These  genera  are  grouped  in  four  subfamilies 
as  follows: 

KEY  TO  SUBFAMILIES  OF  ACRIDIID^. 

Pronotum  (dorsal  wall  of  prothorax)  extending  back  over  the  abdomen  nearly  or  quite 

to   its   tip;     tegmina    (fore   wings)    short   and   scale-like Tettigin^. 

Pronotum  not  extending  back  over  abdomen  or  only   slightly;     tegmina   usually  well 
developed  (sometimes  short  or  wanting). 
Prosternum  (ventral  aspect  of  prothorax)  with  a  prominent  thick  conical  or  cylindrical 

spine AcRiDiiNiE. 

Prosternum  not  spined  (sometimes  a  short,  oblique,  inconspicuous,  obtuse  tubercle). 

Face   very   oblique Tryxalin^. 

Face   nearly  or  quite  vertical (Edipodin^. 

In  the  subfamily  Acridiinae  the  most  conspicuous  and  economically 
important  member   is   the   Rocky   Mountain   or   hateful    migratory  locust, 


Cockroaches,  Locusts,  Grasshoppers,  and  Crickets    137 

Melanopliis  spretiis.  The  invasions  of  the  grain-growing  Mississippi  Valley 
states  by  this  species  have  been  already  mentioned.  In  1866,  1874,  and 
1876  such  invasions  occurred,  and  before  these  still  others.  "Kansas  grass- 
hoppers" had  gained  a  notoriety  which  spelled  ruin  to  the  state.  But, 
strangely,  these  grasshoppers,  or  locusts,  not  only  were  not  Kansas  born, 
but  could  not  even  adopt  Kansas  as  a  home.     The  Rocky  Mountain  locust 


Fig.  168.  Fig.  169. 

Fig.    168. — The   lesser   migratory   locust,   Melanopliis  atlanis,   female.     (After  Lugger; 

natural  size  indicated  by  line.) 
Fig.    169. — The   differential   locust,    Melaiioplus  differentialis,   female.     (After   Lugger; 

natural  size  indicated  by  line.) 


has  its  permanent  breeding-grounds  on  the  plains  and  plateaus  of  Colorado, 
Idaho,  Wyoming,  Montana,  and  British  Columbia,  at  an  altitude  of  from 
2000  to  10,000  feet  above  sea-level,  and  while  able  to  maintain  itself  for 
a  generation  or  two  in  the  low,  moist  Mississippi  Valley,  cannot  take  up 
any  permanent  residence  there.  But  in  those  days  there  were  few  ranches 
and  farms  on  the  great  plains,  and  succulent  corn  and  wheat  were  not  at 


138    Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 

hand  to  feed  the  milUons  of  young  which  hatched  each  spring.  So,  after 
exhausting  the  scanty  wild  herbage  of  their  breeding-grounds,  and  develop- 
ing to  their  winged  stage,  hosts  of  locusts  would  rise  high  into  the  air  until 
they  were  caught  by  the  great  wind-streams  bearing  southeast,  and,  with 
parachute-like  wings  expanded  and  air-sacs  in  the  body  stretched  to  their 
fullest,  would   be  borne  for  a  thousand  miles  to  the  rich  grain-fields  of  the 


Fig. 


170. — The  two-striped  locust,  Melanophis  hivittatus,  female. 
(After  Lugger;    natural  size  indicated  by  line.) 


Mississippi  Valley.  As  far  east  as  the  middle  of  Iowa  and  Missouri  and 
south  to  Texas  these  great  swarms  would  spread;  and  once  settled  to  ground 
and  started  at  their  chief  business,  that  of  eating,  not  a  green  thing  escaped. 
First  the  grains  and  grasses;  then  the  vegetables  and  bushes;  then  the 
leaves  and  fresh  twigs  and  bark  of  trees!  A  steady  munching  was  audible 
over  the  doomed  land!  And  this  munching  was  the  devouring  of  dollars. 
Fifty  millions  of  dollars  were  eaten  in  the  seasons  of  1874-76  alone. 


Cockroaches,  Locusts,  Grasshoppers,  and  Crickets    139 

Remedies  there  were  practically  none;  when  the  summer  hosts  laid 
their  eggs  in  the  ground  for  the  one  generation  that  could  be  reared  in  the 
invaded  land,  these  eggs  could  be  plowed  up,  a  remedy  that  is  used  with 
much  success  in  the  far  western  locust-infested  states;  also  when  the  wingless 
voung  "hoppers"  appeared  in  the  spring  they  could  be  crushed  by  heavy 


Fig. 


171.- 


-The  American  locust,  Schistocerca  americana,  female. 
(After  Lugger;  natural  size.) 


rollers  drawn  across  the  fields  by  horses,  or  burned  by  scattering  straw  over 
the  helpless  host  and  lighting  it.  Both  of  these  remedies  are  also  used  in 
western  locust-fighting.  But  against  the  winged  adults  there  is  little  that 
can  be  done. 

In  Asia  and  South  America,  where  there  are  also  migratory  locusts  (of 
different,  much  larger  species)  the  natives  sometimes  try  to  frighten  away 
an  alighting  swarm  by  smoke  and  noise,  but  such  a  swarm  as  that  which 
passed  over  the  Red  Sea  in  November,  1889,  spread  out  for  over  2000  square 


140    Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 


miles  in  area,  would  be  little  affected  by  a  bonfire.  In  Cyprus  in  1881, 
1300  tons  of  locust-eggs  were  destroyed;  how  many  eggs  go  to  make  a  ton 
one  can  only  faintly  conceive  of. 

There  has  been  no  serious  Rocky  Mountain  locust  invasion  of  the  Missis- 
sippi Valley  since  1876,  and  there  will  probably  never  be  another.  The 
locust  is  being  both  fed  and  fought  in  its  own  breeding  range;    many  are 


Fig.  172.  Fig.  175. 

Fig.  172. — The  emarginate  locust,  Schistocerca  emarginata,  male.  (After  Lugger;  nat- 
ural size.) 

Fig.  173. — The  pale-green  locust,  Hesperotettix  pratensis,  female.  (After  Lugger; 
natural  size  indicated  by  line.) 

Fig.  174. — The  short-winged  locust,  Stenobothrus  curtipennis,  female.  (After  Lugger; 
natural  size  indicated  by  line.) 

Fig.  175. — The  sprinkled  locust,  Chloealtis  conspersa,  male.  (After  Lugger;  natural  size 
indicated  by  line.) 

killed  every  year,  and  for  those  that  are  left  there  is  food  enough  and  to  spare 
in  the  great  grain-fields  of  the  northwest  plains. 

The  genus  Melanoplus,  to  which  the  Rocky  Mountain  locust  belongs, 
is  the  largest  of  all  our  Acridiid  genera,  one  hundred  and  twenty  species 
found  in  the  United  States  belonging  to  it.  Of  these  species  a  very  common 
one  all  over  the  country  is  the  red-legged  locust,  Melanoplus  jemur-riihrum 
(Fig.  167),  which  is  about  one  inch  long,  with  olivaceous  brownish  body, 
clear  hind  wings  and  brownish  fore  wings  that  have  an  inconspicuous 
longitudinal   median  series  of  black   spots    in   the   basal   half    (these   spots 


Cockroaches,  Locusts,  Grasshoppers,  and  Crickets    141 


sometimes  wanting).  The  hind  tibiae  are  normally  red  (sometimes  yellow- 
ish), hence  the  name,  although  these  red  hind  legs  are  common  to  many 
other  locust  species.  The  lesser  migratory  locust,  M.  allanis  (Fig.  168), 
is  a  species  of  about  the  same  size  and  appearance  which  sometimes 
appears  in  great  swarms  and  does  much  injury  to  crops.  The  largest 
species  of  the  genus  is  M.  difjerentialis  (Fig.  169),  over  an  inch  and  a  half  long, 
with  brownish-yellow  body,  fore  wings  without  spots,  and  hind  wings  clear. 
It  is  common  in  the  Southwest,  where,  in  company  with  M.  bknttatus  (Fig. 
170),  nearly  as  large  but  readily  distinguished  by  the  pair  of  longitudinal 


Fig.  176.  Fig.  177.  Fig.  178. 

Fig.  176. — The  short-winged  green  locust,  Dichromorplia  viridis,  female.     (After  Lugger; 

natural  size  indicated  by  line.) 
Fig.    177. — The  spotted-winged  locust,  Orphida  pelidina.     (After  Lugger;    natural  size 

of  male   16-19  mm.,  of  female,   20-24  mm.) 
Fig.  178. — The  Carolina  locust,  Dissoskira   Carolina,   female.     (After   Lugger;  natural 

size  indicated  by  line.) 

pale-yellowish  stripes  extending  from  the  head  across  the  thorax  and  along  the 
folded  wing-covers  nearly  to  their  tips,  it  often  becomes  sufficiently  abundant 
to  do  serious  injury.  These  two  species  are  always  to  be  found  commonly 
in  western  Kansas,  and  bivittatiis  ranges  far  to  the  north,  being  one 
of  Minnesota's  destructive  species. 

Among  the  other  genera  of  the  subfamily  Acridiinae  Schistocerca  is  con- 
spicuous because  of  the  large  size  and  wide  distribution  of  its  species.  The 
American  locust,  S.  americana  (Fig.  171),  measures  three  inches  from  head 
to  tips  of  tegmina,  with  reddish-brown  body  and  a  longitudinal  yellowish 
strip  extending  along  the  head,  thorax,  and  closed  tegmina  nearly  to  their 


142    Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 

tips.  The  tegmina  are  opaque  and  reddish  at  base,  subtransparent  dis- 
tally;  the  great  hind  wings  are  clear  and  transparent.  This  locust  is  com- 
mon in  the  South,  where  it  sometimes  assumes  a  migratory  habit  and 
becomes  very  injurious  to  crops.  The  leather-colored  locust,  S.  alutaceum, 
with  dirty  brownish-yellow  body  and  paler  stripe  on  top  of  head  and  thorax, 


Fig.    179. — The   coral-winged   locust,   Hippiscus  tuberculatus,   female.     (After  Lugger; 
natural  size  indicated  by  line.) 

semi-transparent  tegmina,  and  clear  transparent  hind  wings,  and  the  rusty 
locust,  S.  rubiginosiim,  with  light  dust-red  body  and  opaque  tegmina,  are 
the  common  eastern  representatives  of  this  genus.  Both  are  large  and 
striking  forms. 

The  subfamily  Tryxalin^e  includes  a  number  of  locusts  distinguished 
by  the  sharp  oblique  sloping  of  the  face,  and  in  some  cases  by  the  much 
prolonged  and   pointed  vertex  (region  of  the  head  between  the  eyes).     In 

the    East    the    short-winged    locust, 
Stenohothrus  curtipennis    (Fig.    174), 
recognizable     by    its     short    narrow 
wings,  yellow  under-body,  and  prom- 
inent yellowish  hind  legs  with  black 
knees,  is  a  common  example  of  this 
group.     It  likes  to  hide  among  tall 
grasses,  where  its  sprightly  tumbling 
Fig.    180.— Young     coral-winged     locust,   and    dodging    usually   save   it   from 
Hippiscus  tuberculatus.     (After  Lugger;  capture  despite  its  poor  flying  and 
natural  size  indicated  by  line.)  ,        .  ^,  7  ,  ,    , 

leaping     powers.        The      sprmkled 

locust,  Chlivaltis  conspersa  (Fig.  175),  is  an  abundant  species  through- 
out the  East.  It  is  light  reddish  brown  sprinkled  with  black  spots, 
and  has  pale  yellowish-brown  tegmina  with  many  small  dark-brown  spots, 
the  wings  being  clear;  it  is  about  three-fourths  of  an  inch  long.  The 
males  have  the  sides  of  the  pronotum  shining  black.  This  locust  lays  its 
eggs  in  rotten  stumps  or  other  slightly  decayed  wood.  Blatchley  discovered 
a  female  in  the  act  of  boring  a  hole  for  her  eggs  in  the  upper  edge  of  the 
topmost  board  of  a  six-rail  fence.  One  of  the  most  grotesque  of  all  the 
locusts  is  a  member  of  this  subfamily  named  Achtinim  brevipenne.  The 
body  is  very  long  and  thin,  measuring  an  inch  and  a  half  in  length  by  one- 


Cockroaches,  Locusts,  Grasshoppers,  and  Crickets    143 

tenth  of  an  inch  wide  in  the  broadest  part;  the  head  is  pointed  and  pro- 
jects far  forward  and  upward,  the  face  being  very  obhque.  The  wings 
are  short  and  the  body  color  brown.  Comstock  found  this  locust  quite 
common  in  Florida  on  the  "wire-grass"  which  grows  in  the  sand  among 
the  saw-palmettoes,  and  "so  closely  did  their  brown  linear  bodies  resemble 
dry  grass  that  it  was  very  difficult  to  perceive  them."  So  the  grotesqueness 
has  its  use. 

The    subfamily   (Edipodina^    is   well  represented  in  the  United  States, 


Fig.   181. — Hippiscus  tigrinus,  female.      (After  Lugger;    nat.  size  indicated  by  line.) 

containing  twenty- four  genera  and  about  140  species.  Almost  all  the  familiar 
locusts  with  showy  colored  hind  wings  belong  to  this  subfamily.  One 
of  the  commonest  species  all  over  the  United  States  and  Canada  is  the 
Carolina  locust,  Dissosteira  Carolina  (Fig.  178),  easily  recognized  by  its 
black  hind  wings  with  broad  yellow  or  yellowish-white  margin  covered  with 
dusky  spots  at  the  tip.  Its  body  color  is  pale  yellowish  or  reddish  brown, 
and  it  measures  1^-2  inches  in  length.  It  flies  well;  the  males  have  the 
habit  of  hovering  in  the  air  a  few  feet  above  the  ground  and  making  a  loud 


144    Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 


Fig.  182. — The  yellow-winged  locust,  Arpltia 
sulphiirea.  (After  Lugger;  natural  size  of 
male  23-26  mm.,  of  female  28-30  mm.) 


"clacking."      The    species    of    Hippiscus    are    heavy,    broad-bodied    forms 

with  wings  reddish  or  yellow- 
ish at  base,  then  a  broad  black- 
ish band,  and  the  apex  and 
margin  clear.  The  fore  wings 
and  body  are  yellowish  to 
brown,  with  darker  blotches 
and  speckles.  H.  discoideus, 
with  wings  red  on  basal  half, 
is  common  in  the  East.  H, 
tuherculatiis  (Figs.  179  and  180), 
the  coral-winged  locust,  or  king 
grasshopper,  also  with  red 
wing-disks,  is  common  in  the 
Mississippi  Valley ;  it  makes 
a  very  loud  rattling  while  in 
the  air.  The  genus  Arphia, 
also  characterized  by  wings 
with  bright  red  or  yellowish 
disks  but  having  the  fore  wings 
without  large  spots  or  blotches, 
usually  not  even  speckled,  and 
with  the  body  slenderer  than 
in  Hippiscus,  comprises  about 
twenty  species  scattered  over 
the  whole  country.  A.  xan- 
thopiera,  with  plain  smoky 
brown  fore  wings  and  upper 
body,  and  hind  wings  with 
bright  yellow  disk,  broad  smoky 
outer  band  and  clearer  apex, 
is  common  in  the  East;  A. 
tenebrosa  (Fig.  183),  with  brown 
and  clayey-speckled  fore  wings 
and  upper  body  and  hind 
wings  with  coral-red  disk  and 
smoky  broad  outer  band  fad- 
ing out  in  apex,  is  common 
in  the  West.  The  green- 
striped      locust,     Chortophaga 


Fig.  183. — Arphia  tenebrosa.     (After  Lugger;   nat- 
ural size  indicated  by  line.) 


viridijasciata  (Figs.   184  and   185),  abundant  and  familiar  in    the  East  and 
Mississippi  Valley,  appears   in   two  forms;    in  one,   the  head,  thorax,  and 


Cockroaches,  Locusts,  Grasshoppers,  and  Crickets    145 


Fig.  1S4. — The  green-striped  locust,  Chortophaga  viridifasciata,  form  virginiana,  female. 
(After  Lugger;    natural  size  indicated  by  line.) 


Fig.  186. 


Fig.  187. 


Fig.  185. — The  green-striped  locust,  Chortophaga  viridifasciata,  form  virginiana,  male. 
(After  Lugger;    natural  size  indicated  by  line.) 

Fig.  186.— The  clouded  locust,  Encoptolophus  sordidus,  male.  (After  Lugger;  nat- 
ural size  indicated  by  line.) 

Fig.  187. — The  pellucid  locust,  Camnula  pelliicida,  female.  (After  Lugger;  natural 
size  indicated  by  hne.) 


146    Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 


femora  are  green  and  there  is  a  broad  green  stripe  on  each  wing-cover; 
the  other  form  is  dusky  brown  all  over;  both  are  about  i  inch  (male)  to  i^ 
inches  (female)  long,  and  have  a  distinct  sharp  little  median  crest  on  the 


Fig.  190. 


Fig.  iqi. 


Fig.  188. — Barren-ground  locust,  Spharagemon  holli,  male.  (After  Lugger;  natural  size 
of  male  20-22  mm.,  of  female  27-33  rnn^-) 

Fig.  189. — Spharagemon  collare,  race  scudderi,  male.  (After  Lugger;  natural  size  in- 
dicated by  line.) 

Fig.  190. — The  long-horned  locust,  Psinidia  jenestralis,  male.  (After  Lugger;  natural 
size  indicated  by  line.) 

Fig.    191. — Circotettix  verruculatus,  male.     (After  Lugger;  natural  size  indicated  by  line.) 

pronotum.  The  clouded  locust,  Encoptolophus  sordidus  (Fig.  186),  is  another 
species  very  common  in  the  fall;  it  is  about  an  inch  long,  dusky  brown 
mottled  with  darker  spots;   the  wing-covers    are  blotched    and    the  wings 


Cockroaches,  Locusts,  Grasshoppers,  and  Crickets    147 


clear  and  transparent;  the  prothorax  looked  at  from  above  appears  to  be 
"pinched"  at  its  middle.  The  males  make  a  loud  crackling  when  in  the 
air. 

It  is  famihar  knowledge  that  locusts  which  are  readily  seen  in  the  air 
are  extremely  difficult  to  distinguish  when  alighted.  This  concealment, 
resulting  from  a  harmonizing  of  the  body  color  with  that  of  the  grass  or 
soil,  is  of  course  an  advantage  to  the  locust  in  its  "struggle  for  existence " 
and  is  technically  known  as  protective  resemblance  (see  Chapter  XVII).  No 
locusts  show  this  protective  resemblance  better 
than  the  species  of  Trimerotropis  (Fig.  193) 
especially  familiar  in  the  western  states.  The 
colors  of  various  individuals  of  a  single  species 
vary  with  the  soil  colors  of  the  locality,  ranging 
from  whitish  to 
brownish  to  slaty 
and  bluish.  I  have 
taken  series  of  spe- 
cimens of  Trimero- 
tropis sp.  in  Colorado 
showing  this  whole 
range  of  ground 
coloration. 


Fig.  193. 
(After  Lugger;    natural  size  indicated  by  line.) 


Fig.  192. — Mestohregma  cincta,  male 

Fig.  193. — The  maritime  locust,  Trimerotropis  maritima,  female 
ural  size  indicated  by  line.) 


(After  Lugger;    nat- 


The  subfamily  Tettiginae  includes  the  strange  little  Acridiids  known  as 
"grouse-locusts.".  They  are  all  under  f  inch  in  length,  and  most  of 
them  are  less  than  h  inch.  They  have  the  wing-covers  reduced  to  mere 
scales,  but  the  pronotum  is  so  long  that  it  extends  back  over  the  rest  of  the 


148    Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 


thorax  to  the  abdomen  and  more  or  less  covers  it.  In  some  species  the 
pronotum  actually  extends  beyond  the  tip  of  the  abdomen.  The  head  is 
deeply  set  in  the  prothorax,  the  prosternum  being  expanded  into  a  broad 
border  which  nearly  covers  the  mouth.  As  all  the  grouse-locusts  are  dark- 
colored  and  without  any  conspicuous  markings,  and  choose  for  habitat  the 
dark   ground   along   streams   and   ponds,   or   swampy   meadows,   they   are 


Fig.  194.  Fig.  105.  Fig.   196. 

Fig.   194. — Nomotetlix  parvus.     (After  Lugger;  natural  size  indicated  by  line.) 
Fig.    195. — Tettigidea   lateralis.     (After   Lugger;     natural   size   indicated   by   line.) 
Fig.   196. — Tettix  granulatus,  and  pronota  of  two  varieties,     (.\fter  Lugger;  natural  size 
indicated  by  line.) 


infrequently  seen  except  by  persistent  students.  They  vary  much  in  colora- 
tion and  sHght  markings,  and  harmonize  thoroughly  with  the  soil  on  which 
they   habitually  live.     They   feed   on   lichens,   moulds,   germinating   seeds, 

and  sprouting  grasses,  and  are  said  to  eat 
surface  mud  and  muck  containing  or  largely 
consisting  of  decaying  vegetable  matter.  The 
eggs  are  laid  in  a  pear-shaped  mass  in  a 
shallow  burrow;  in  May  and  June  the  young 
hatch  in  from  sixteen  to  twenty-five  days, 
becoming  mature  in  late  fall,  or  sometimes 
not  until  the  following  spring.  The  nymphs 
and  adults  hibernate,  becoming  active  again 
early  in  spring.  A  common  species  is  Tettix 
gramdatus  (Fig.  196),  slender,  length  about 
\  inch,  and  with  the  narrow  pointed  pronotum 
extending  beyond  the  abdomen.  This  species 
hibernates  among  rubbish  and  loose  bark,  but 
is  more  or  less  active  on  warm  winter  days. 
It  is  plentiful  all  through  the  rest  of  the  year 
on  its  feeding-grounds.  T.  ornatiis  (Fig.  197)  is  a  shorter,  more  robust 
species,  and  is  marked  with  black  spots  and  indefinite  yellow  blotches  as 


Fig.  197. — Tettix  omatus.  (After 

Lugger;  natural  size  indicated 

by  line.) 
Fig.    198. — Paratettix  cucullatus. 

(After    Lugger;    natural    size 

indicated  by  line.) 


Cockroaches,  Locusts,  Grasshoppers,  and  Crickets     149 


indicated  in  tlie  figure.  In  the  genus  Tettigidea  the  antennas  have  from 
15  to  22  segments,  while  in  Tettix  they  have  only  12  to  14  segments.  Tet- 
tigidea lateralis  (Fig.  195)  is  a  common  species  yellovi^ish  brown  in  color, 
more  yellowish  underneath.  It  is  rather  robust  and  the  pronotum  extends 
beyond  the  tip  of  the  abdomen. 

Included  in  the  family  Locustidae  are  katydids,  meadow  grasshoppers, 
cave-crickets,  wingless  crickets,  western  crickets,  Jerusalem  crickets,  and 
what  not,  but  no  locusts.  The  general  reader  of  natural  history  should 
always  keep  clearly  in  mind  the 
sharp  distinction  made  by  natu- 
ralists between  "scientific"  and 
"vernacular"  names.  The  ver- 
nacular name  locust  is  applied 
to  insects  of  the  family  Acri- 
diidae,  but  not  to  any  of  the 
members  of  the  family  whose 
scientific  name  is  Locustidae. 
Of  the  Locustids  the  best 
known  representatives  are  un- 
doubtedly the  katydids.  Anna 
Botsford  Comstock,  the  nature- 
study  teacher  of  Cornell  Uni- 
versity, introduces  them  to  her 
readers  as  follows:  "The 
chances  are  that  he  who  lies 
awake  of  a  midsummer  night 
must  listen,  whether  he  wishes 
to  do  so  or  not,  to  an  oft- 
repeated,  rasping  song  that 
says,  'Katy  did,  Katy  did;  she 
did,  she  didn't,'  over  and  over 
again.  There  is  no  use  of  won- 
dering what  Katy  did  or  didn't 
do,  for  no  mortal  will  ever 
know.       If,     when     the     dawn 

comes,    the     listener    has    eyes     r?  t,      ji     ■      j  1       ,■  1       1 .    r     •  1 

-'  riG.  igg. — Broad-winged  katydid,  and  leaf  with 

sharp  enough  to  discern  one  of  katydid  eggs  along  edge.  (Natural  size.) 
these  singers  among  the  leaves  of  some  neighboring  tree,  never  a  note  of 
explanation  will  he  get.  The  beautiful,  finely  veined  wings  folded  close 
over  the  body  keep  the  secret  hidden,  and  the  long  antenna?,  looking  like 
threads  of  living  silk,  will  wave  airily  above  the  droll  green  eyes  as  much 
as  to  say,  'Wouldn't  you  like  to  know?'" 


150    Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 


The  katydids  are  rather  large,  almost  always  green  insects  that  live  in 
trees  and  shrubs,  where  they  feed  upon  the  leaves  and  tender  twigs,  some- 
times doing  considerable  injury.  With  almost  all  the  other  Locustids, 
they  will  also  take  animal  food  if  accessible,  and  some  of  the  ground- 
inhabiting  forms  undoubtedly  depend  largely  on  animal  substances  for 
food.  The  color  and  form  of  the  wing-covers  and  body  serve  to  make  them 
nearly  indistinguishable  in  the  foliage,  and  as  they  do  not  flock  together 
in  numbers,  they  are  not  frequently  seen.  Their  love-calls  or  songs,  how- 
ever, make  the  welkin  ring  at  night  from 
midsummer  until  the  coming  of  frost.  Few 
katydids  sing  by  day:  it  would  bring  their 
enemies,  the  birds,  down  on  them;  but  as 
twilight  approaches,  the  males  begin  their 
shrilling,  which  is  kept  up  almost  constantly 
till  daylight.  Like  the  sound-making  Acri- 
diids  the  musical  Locustids  have  a  pair  of 
special  auditory  organs,  or  ears,  for  hearing 
these  love-songs.  These  ears  are  tympanal 
organs  situated  one  in  the  base  of  each  fore 
tibia  (the  Acridiid  ears  are  on  the  upper 
part  of  the  first  abdominal  segment),  and 
consist  of  a  thin  place  in  the  chitinized 
body-wall  (the  tympanum),  a  resonance- 
chamber  inside,  and  a  special  arrangement 
of  nerves  and  ganglia.  There  are  several 
genera  of  these  Locustids,  corresponding  to 
the  distinctions  popularly  made  under  the 
vernacular  names  narrow-winged,  round- 
winged,  angular- winged,  oblong  leaf- winged, 
and  broad-winged  katydids.  The  true 
katydid  is  one  of  the  last-named  forms, 
the  commonest  and  most  wide-spread  species 
being  Crytophylliis  concavus  (Fig.  200). 
It  is  bright  dark-green,  and  is  rarely 
distinguished  when  at  rest  in  the  foliage,  although  familiar  to  all  from  its 
shrill  singing.  When  specimens  of  katydids  are  collected  and  examined, 
concavus  may  be  readily  distinguished  by  the  fact  that  its  wings  are  shorter 
than  the  wing-covers,  and  these  latter  are  very  convex  and  so  curved  around 
the  body  that  their  edges  meet  above  and  below.  The  ovipositor  of  the 
female  is  short,  compressed,  slightly  curved  and  pointed.  This  katydid 
is  most  in  evidence  in  late  summer.  People  disagree  about  the  melody 
and  alleged  charm  of  the  song.     Many  cannot  distinguish  the  "katydid" 


Fig.  200. — Broad-winged  katydid, 
CyrtophyUits  concavus,  male. 
(After  Harris;  natural  size.) 


Cockroaches,  Locusts,  Grasshoppers,  and  Crickets    151 


Fig.    201. — Cyrtophyl- 
liis  concavus  sp. 


syllables,  and  Scudder,  an  experienced  student  of  the  Orthoptera,  says  that 

the  note,  which  sounds  like  xr,  has  a  shocking  lack  of  melody,  adding  that 

the  poets  who  have  sung  its  praises  must  have  heard 

it  at  the  distance  that  lends  enchantment.     The  sounds 

are  made  by  the  males  exclusively,   and  result  from 

the  rubbing  together  of  the  bases  of  the  wing-covers, 

which  have  the  veins  and  membrane  specially  modified 

for  this  purpose  (see  Fig.  201).     Concavus  lays,  in  the 

autumn,  flattened  dark  slate-colored  eggs,  about  |  inch 

long  and  one-third  as  wide,  in  two  rows  along  a  twig, 

the  eggs  overlapping  a  little.     These  eggs  hatch  in  the 

following  spring,  and  the  young,  like  the  adults,  feed 

on  the  foliage  of  the  tree. 

The  oblong  leaf-winged  and  round-winged  katydids  belong  to  the  genus 

Amblycorypha,  and  they  can  be  readily  recognized  by  the  broad,  oblong, 

and  rounded  wing-covers,  and  the  strongly  curved  ovipositor  of  the  female, 

with  serrated  tip.     They  are  grass-green  and  have  the  wings  longer  than 

the  wing-covers.     The  oblong  leaf-winged  species,  A.  oblongi folia  (Fig.  202), 

is  2  inches  long  to  tips  of  folded 
wings,  while  the  round  -  winged 
species,  A.  rotundijolia,  is  i\  in- 
ches or  less  in  length.  These 
katydids  prefer  bushes  and  tall 
weeds  or  even  grass-clumps  to 
tree-tops.  Oblongijolia  is  said  by 
McNeill  to  make  a  "quick  shuf- 
fling sound  which  resembles 
'  katy '  or  '  katydid  '  very  slight- 
ly," while  the  song  of  rotun- 
dijolia is   said  by   Scudder  to  be 

made   both   day  and  night  without  variation  and   to  consist  of  two  to   four 

notes,  sounding  like  chic-a-chee,  run  together  and   repeated    generally  once 

in  about  five  seconds  for  an  indefinite  length  of  time. 


Fig.  202. — The  oblong  leaf-winged  katydid, 
Amblycorypha  oblongijolia,  female.  (After 
Lugger;    natural  size.) 


Fig.    203. — Angular-winged    katydid,    Microcentrum   laiirifolium,    male. 
(After  Riley;  natural  size.) 

The  angular-winged  katydids,  genus  Microcentrum,  are  large,  numerous, 


152    Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 

and  the  most  familiarly  known  of  all.  The  best-known  species,  M.  retinervis, 
is  over  2  inches  long  (from  head  to  tip  of  folded  wings) ;  the  overlapping 
dorsal  parts,  of  the  wing-covers  form  a  conspicuous  angle  with  the  lateral 
parts,  hence  the  name  "angular-winged."  The  ovipositor  of  the  female  is 
very  short,  strongly  curved,  and  with  a  bluntly  pointed,  finely  serrate  tip.  The 
song  of  M.  laurijoliiim  (Fig.  203)  is  said  to  sound  like  tic  repeated  from 
eight  to  twenty  times,  at  the  rate  of  four  a  second.  The  eggs,  of  which  each 
female  lays  from  100  to  150  in  the  fall,  are  grayish  brown,  flat,  and  long- 
oval,  about  \  inch  long  by  \  inch  wide,  and  are  glued  in  double  rows  along 
twigs  or  on  the  edges  of  leaves  (Fig.  199).  I  have  found  them  on  thorns 
of  the  honey-locust,  and  Howard  once  received  "a  batch  from  a  western 
correspondent  which  was  found  on  the  edge  of  a  freshly  laundried  collar 
which  had  lain  for  some  time  in  a  bureau  drawer."  The  rows  are  side  by 
side,  and  the  fiat  eggs  overlap  each  other  in  their  own  row.  The  young 
hatch  in  spring  and,  slowly  growing,  moulting,  and  developing  wings,  reach 
full  size  and  maturitv  by  the  middle  of  the  summer. 


Fig.  204a.  Fig.  204&. 

Fig.  204a. — The  fork-tailed  katydid,  Scudderia  jiircala,  female.    (After  Lugger;   nat.  size.) 
Fig.  2046. — The  fork -tailed  haXydid,  Scudderia  jnrcata,Tadi\e.     (After  Lugger;    nat.  size.) 

The  narrow-winged  katydids,  belonging  to  the  genus  Scudderia  (Figs.  204- 
206),  are  smaller  than  the  broader-winged  kinds,  being  not  more  than  i^ 
inches  in  length  to  tip  of  folded  wing-covers,  and  the  wing-covers  are  narrow 
and  of  nearly  equal  width  for  their  whole  length.     The  ovipositor  is  broad. 


Fig.   205.  Fig.  206. 

Fig.  205. — Scudderia  pistillala,  female.     (After  Lugger;    natural  size  ) 
Fig.  206.— Scudderia  pistillala,  male.     (After  Lugger;    natural  size.) 

compressed,  and  curves  sharply  upward.  These  insects  frequent  shrubbery 
and  bushes,  or  coarse  grasses  and  weeds  along  ravines  or  ponds;  also 
marshes,  cranberry-bogs,  and  similar  wet  places.     Their  flight  is  noiseless 


Cockroaches,  Locusts,  Grasshoppers,  and  Crickets    153 

and  zigzag,  and  when  pursued  they  will  take  to  the  lower  branches  of  trees, 
especially  oaks  if  near  by.  The  males  sing  somewhat  in  daytime  as  well 
as  at  night,  and  have  different  calls  for  the  two  times.  The  females  lay 
their  eggs  in  the  edges  of  leaves,  thrusting  them  in  between  the  upper  and 
lower  cuticle  by  means  of  their  flattened  and  pointed  ovipositor. 

While  almost  all  katydids  are  green,  a  few  exceptions  are  known. 
Scudder  has  found  certain  pink  individuals  belonging  to  a  species  normally 
green.     In  mountain  regions  a  few  species  of  gray-  or  granite-colored  katy- 


FiG.  207. — The  sword-bearer,  Conocephalus  ensiger,  female.     (After  Lugger;  nat.   size.) 

dids  are  known,  the  color  here  being  quite  as  protective  as  the  green  of  the 
lowland  forms,  for  these  mountain  species  alight  to  rest  on  the  granite  rocks 
of  the  mountainside.  I  have  found  these  granite  katydids  in  the  Sierra 
Nevada  of  California. 


Fig.  208.  Fig.  209. 

Fig.   208. — The  sword-bearer,  Conocephalus  ensiger,  male.     (After  Lugger;    nat.  size.) 
Fig.   209. — A    common    meadow    grasshopper,     Orchelimum    vulgare,    female.      (After 
Lugger;    natural  size  indicated  by  line.) 

The  meadow  grasshoppers  are  small,  katydid-like  Locustids,  green  and 
long-winged,  with  long,  slender  hind  legs  and  with  the  characteristic  slender 
thread-like  antennae  longer  than  the  body.  These  antennae  readily  distinguish 
them  from  any  of  the  locusts  (Acridiidae)  which  may  be  found  in  their  com- 
pany.    The  meadow  green  grasshoppers  abound  in  pastures  and  meadows. 


154    Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 

and  they  dislike  to  take  to  wing,  trusting,  when  alarmed,  to  spry  leaping  or 
clever  wriggling  away  and  hiding  among  the  lush  grasses.  Their  green 
color  of  course  aids  very  much  in  protecting  them  from  enemies.     They 

include  three  common  genera,  viz.: 
Conocephalus  (Figs.  207  and  208),  or 
cone-headed  grasshoppers  or  sword- 
bearers  with  head  produced  into  a 
long,  pointed,  forward-projecting,  cone- 
like process,  slender  body,  and  very 
Fig.  210.— a  common  meadow  grasshop-  long,  slender,  straight  or  angled,  sword- 
per,  Orchelimum  vulgare,   male.     (After    like  ovipositor;   Orchehmum  (Figs.  209 

Lugger:  natural  size  indicated  by  line.)  a  \    ^-i         ^      ^  j  v. 

^^  ^  and  210),  the  stout  meadow  grasshop- 

pers, with  blunt  head,  robust  body,  and  short,  slightly  curved  ovipositor; 
and  Xiphidium  (Fig.  211),  the  slender  or  lance-tailed  meadow  grasshoppers, 
with  blunt  head,  small  and  slender,  graceful  body,  and  nearly  straight, 
slender   ovipositor,    sometimes  larger  than  the  body.     The  eggs  of  all  these 


Fig.  211. — The  lance-tailed  grasshopper,  Xiphidium  attenuatiim,  female. 
(After  Lugger;  natural  size  indicated  by  line.) 

are  laid  usually  in  the  stems  or  root-leaves  of  grasses,  or  the  pith  of  twigs. 
The  color  is  usually  green,  but  a  few  are  light  reddish  brown.  The  song 
of  the  males  is  faint  and  soft,  and  is  made  by  day  as  much  as  by  night. 


Fig.  212.  Fig.  213. 

Fig.    212. — Udeopsylla  robusta,    female.     (After  Lugger;    nat.   size   indicated  by   line.) 
Fig.   213. — The  spotted  wingless  grasshopper,   Ceuiophilus  macidatiis,   female.     (After 
Lugger;    natural  size  indicated  by  line.) 

The   family   Locustidae   includes   numerous   wingless   forms,   some   with 
no  remaining  trace  of  wing-covers  or  wings,  some  with  rudimentary  or  scale- 


Cockroaches,  Locusts,  Grasshoppers,  and  Crickets     irr 

like  remnants  of  wing-covers.     These  latter  kinds  can  sing  because  the  parts 
retained   are   the   sound-producing  bases  of  the   wing-covers.     The  genus 


Fig. 


214. 


-Diestrammena  mannorata,  male;  a  Japanese  locust  species  found  in  Minnesota. 
(After  Lugger;    natural  size.) 

Ceuthophilus   (Figs.    213  and   215)   includes   the   various  species  of  stone, 
or  camel,  crickets  found  all  over  the  country,  recognizable  by  their  thick, 


Fig.    2JS.— Ceuthophilus  lapidicolus,  female.     (After  Lugger;  natural   size 
indicated  by  line.) 

smooth,  wholly  wingless,  brownish  body  with  arched  back  and  head  bent 
downwards  and  backwards  between  the  front  legs.     They  are  nocturnal, 


Fig.  216.  y^^   _,^^ 

Fig.  216.— The  shield-backed  grasshopper,  Allanlicus  pachymerus,  male.     (After  Lue- 

ger;    natural  size  indicated  by  line.) 
Fig.  217.— The  California  shield-backed  grasshopper,  Tropizaspis  sp.,  female.  (Nat.  size  ) 

and  during  the  day  hide  under  stones  or  logs  along  streams  or  in  damp  woods. 
The  individuals  of  a  species  which  live  in  the  burrows  of  certain  turtles  in 
Florida  are  called  "gophers."  Perhaps  the  commonest  species,  extending 
from  New  England  to  the  Rocky  Mountains,  is  the  "spotted  wingless  grass- 


156    Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 

hopper,"  C.  maculatus  (Fig.  213),  with  sooty  brown  body  dotted  with 
pale  spots.  Some  of  the  wingless  Locustids  are  found  in  caves,  and  these 
are  either  bhnd  or  have  the  eyes  much  reduced.  One  of  these  cave-crickets, 
Hadoenuciis  siibterraneus,  is  common  in  the  larger  caves  of  Kentucky,  where 
it  may  be  found  creeping  about  on  the  walls.  Garman  states  that  it  speedily 
dies  when  removed  from  the  cave.     The  genus  Atlanticus  comprises  duU- 


FiG.  218. — The  western  cricket,  Anabrus  pttrpurascens,  male.     (After  Lugger;   nat.  size.) 


colored  species  with  the  pronotum  extending  like  a  shield  back  over  the 
base  of  the  abdomen,  and  although  the  hind  wings  are  wanting,  rudimentary 
wing-covers  are  present,  and  in  the  males  carry  a  circular  stridulating  organ. 

These  are  called  "shield-backed  grasshoppers" 
and  are  to  be  found  in  dry  upland  woods  and  on 
sloping  hillsides  with  sunny  exposure.  The  two 
common  species  in  the  East  and  the  Mississippi 
Valley  are  .4.  dorsalis,  with  pronotum  well  rounded 
behind,  and  A.  pachymerus  (Fig.  216),  with  pro- 
notum nearly  square. 

A  genus  similar  to  Atlanticus  found  commonly 
in  California  is  Tropizaspis  (Fig.  217),  the  males 

( 


Fig.  219.  Fig.  220. 

Fig.   2I(). — The   western  cricket,  Anahriis  purpurascens,  female.     (After  Lugger;   nat- 
ural size.) 
Fig.    220. — The    Jerusalem    cricket,    Stenopelmahis   sp.     (Natural    size.) 


Cockroaches,  Locusts,  Grasshoppers,  and  Crickets     157 


of  which  sing  very  pleasantly.      In   Idaho   and    other   northwestern   states 

a   large   corpulent   wingless  Locustid,  called   the  western   cricket,  Anahrus 

piirpurascens   (Figs.    218  and   219),  often  occurs  in 

such   numbers  as   to   be   very  destructive   to  crops. 

The   body   of    this    cricket  is    i^   inches   long  and 

h   inch    thick.     The    ovipositor    is  three-fourths   as 

long  as  the  body,  slightly  curved,  and  sword-shaped 

with    a    sharp    point.     This    species   forms   march- 
ing armies  in  Nevada,  with  two  miles  of  front  and 

a    thousand    feet  of  depth.     On  the  Pacific   Coast 

occurs  a  large,  awkward,  thick-legged,  transversely 

striped  form,  Stenopelmatus,  called  sand-cricket  or 

Jerusalem    cricket   (Fig.    220).     It    is    found  under 

stones  or  in  the  soil,  has  a  large  smooth  head  with 

"baby-face,"  and  is  believed  to  feed  on  dead  plant 

or  animal  matter. 

The  crickets  that  we  know   best  are   the  black 

and  brown  ones  of  the   house  and  the  fields;   but 

there  are  members  of  the  cricket  family,  the  Gryl- 

lidae,  that  live  in  trees  and  are  pale  greenish  white,  fig.    221.  -A    common 

and  others  that  burrow  into  the  ground  and  have      cricket,  Gryllus  pennsyl- 

broad  shovel-like   lore  fee,,  and  still  other  curious     I™;  '™»|.l,  i^" 

little  wingless  pygmies  that  live  as  guests  in  ants'      dicated  by  line.) 

nests.     But  the  house-  and  field-crickets  represent  the  more  usual  or  we 

might  say  normal  and  typical  kind  of  Gryllid; 
the  others  are  modifications  or  ofTshoots  of  this 
type,  both  in  habit  and  structure.  In  all  the 
antennae  are  long  and  slender  (except  in  the 
burrowing  forms,  longer  than  the  body),  the  hind 
legs  long  and  thickened  for  leaping,  and  the 
ovipositor,  when  exserted  and  visible,  long,  slender, 
subcylindrical  and  lance-  or  spear-like.  Well- 
developed  wings  and  wing-covers  are  present  in 
most  species,  and  the  males  are  provided  with  a 
very  effective  stridulating  organ  on  the  bases  of 
the  wing-covers. 

In  the  familiar  black,  bright-eyed,  loud-voiced 
house-  and  field-crickets  the  wing-covers  when 
folded  on  the  body  are  flat  above  and  bent  down 
sharply  at  the  edge  of  the  body  like  a  box-cover,  and  the  veins  in  the  males 
are  curiously  changed  in  course  and  specially  thickened  and  roughened 
to  make  a  sound-producing  organ.     This  organ  is  illustrated   in  Fig.   222. 


Fig.  222. — Cricket  and  file 
(part  of  the  sound-making 
apparatus).  (Cricket  nat- 
ural size;  the  file  greatly 
magnified.) 


158     Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 


To  sing,  the  males  lift  their  wing-covers  at  an  angle  of  about  45°  over  the 
back,  and  strongly  rub  together  the  bases.  Their  chirping  is  made  either 
in  the  daytime  or  night,  and  is  a  love  call  or  song  for  their  mates.  We  have 
several  common  crickets  in  dwellings,  one,  Gryllus  domesticus  (Fig.  223) 
being  the  European  house-cricket,  the  "cricket  on  the 
hearth,"'  which  is  becoming  at  home  here,  being  espe- 
cially met  with  in  Canada.  It  is  pale  brown  and  less 
than  an  inch  long.  Gryllus  luctiiosus  and  G.  assimilis 
are  two  native  crickets  which  are  common  in  houses; 
they  are  black  with  brownish-black  wing-covers,  larger 
and  nifire  robust  than  domesticus,  and  with  the  folded 
wings  projecting  backward  beyond  the  wing-covers  like 
pointed  tails.  These  house-crickets  are  most  active 
at  night,  and  seem  to  have  a  taste  for  almost  any 
food-product  in  the  house.  They  will  eat  each  other 
when  other  food  is  scarce.  If  they  become  so  nu- 
merous in  the  house  that  they  need  to  be  got  rid  of, 
advantage  may  be  taken  of  their  liking  for  sweet 
liquids  by  exposing  smooth-walled  vessels  half  filled 
with  such  liquids,  into  which  the  crickets  will  fall  and 
drown  in  their  attempts  to  get  at  the  food.  The  most 
abundant  and  wide-spread  outdoors  cricket  is  Gryllus 
abbreviatus  (Fig.  224),  the  short-winged  field-cricket. 
The  wings  are  sometimes  wanting,  but  more  often  pres- 
ent and  shorter  than  the  wing-covers,  which  in  the  females  are  themselves 
unusually  short,  reaching  but  half-way  to  the  end  of  the  abdomen.  The 
slender  ovipositor  is  as  long  as  the 
body,  and  the  hind  femora  are  ver}- 
thick  and  have  a  red  spot  at  the 
base  on  either  side.  The  life-history 
of  this  common  insect  is  not  yet  fully 
known,  some  writers  stating  that  the 
eggs  laid  in  autumn  do  not  hatch  until 
the  following  spring,  the  insect  thus 
passing  the  winter  in  the  egg  stage,  Fig.  224.— The  short-winged  cricket,  Gry/n^ 
while   others  have   taken   half-grown  abbreviatus.     (Natural  size.) 

young  from  beneath  logs  in  late  autumn  and  in  midwinter.  The  field- 
cricket  is  "nocturnal,  omnivorous,  and  a  cannibal.  Avoiding  the  light 
of  day,"  says  Blatchley,  "he  ventures  forth  as  soon  as  darkness  has  fallen, 
in  search  of  food,  and  all  appears  to  be  fish  which  comes  to  his  net.  Of 
fruit,  vegetables,  grass,  and  carrion  he  seems  equally  fond,  and  does  not 


Fig.  223. — The  Euro- 
pean house  -  cricket, 
Gryllus  domesticus, 
female.  (After  Lug- 
ger; natural  size  in- 
dicated by  line.) 


Cockroaches,  Locusts,  Grasshoppers,  and  Crickets     159 


hesitate  to  prey  upon  a  weaker  brother  when  opportunity  offers.     I  have 

often  surprised  them  feasting  on  the  bodies  of  their  com- 
panions; and  of  about   forty  imprisoned   together  in    a 

box,  at   the  end  of  a  week   but   six  were  Hving.     The 

heads,  wings,  and  legs  of  their  dead  companions  were  all 

that  remained  to  show  that  the  weaker  had  succumbed 

to   the   stronger — that   the   fittest,  and    in    this  case  the 

fattest,  had  survived  in  the  deadly  struggle  for  existence." 
These   crickets   hve   in   cracks  in  the   soil,  or  under 

stones  or  logs,  or  sometimes  make  burrows. 

The    genus    Nemobius    contains   a   number    of    little 

crickets  known  as  "striped  ground-crickets,"  which  are 

less  than  half  an  inch  long,  are  dusky  brownish  with  hairy 

head   and  thorax,  and    have  faint  blackish  longitudinal 

stripes  on  the  head.     "Unlike   their  larger  cousins,  the 

field-crickets,  they  do  not  wait  for  darkness  before  seek- 
ing their  food,  but  wherever  the  grass  has  been  cropped 

short,  whether   on    shaded   hillside  in   the  full   glare  of  ^'s^tri  ed'^TouTd^! 

the  noonday  sun  along  the  beaten  roadway,  mature  speci- 
mens may  be  seen  by  hundreds  during  the  days  of  early 

autumn."       They  are  powerful  jumpers  and  readily  evade 

attempts  to  capture  them.     They  feed  on  living  vegetation 

and  on  all  kinds  of  decaying  animal  matter,  and  because  of 
their  abundance  and  voracious  appetite  must  do  much 
damage  at  times.  Scudder  gives  the  following  account  of 
the  singing  of  the  wingless  striped  cricket,  Nemobius  vittatus 
(Fig.  225),  our  commonest  species:  "The  chirping  of  the 
striped  cricket  is  very  similar  to  that  of  the  black  field-cricket, 
and  may  be  expressed  by  r-r-r-u,  pronounced  as  though  it 
were  a  French  word.  The  note  is  trilled  forcibly,  and  lasts 
a  variable  length  of  time.  One  of  these  insects  was  once 
The  observed  while  singing  to  its  mate.  At  first  the  song  was 
mild  and  frequently  broken;  afterwards  it  grew  impetuous, 
forcible,  and  more  prolonged;  then  it  decreased  in  volume 
(Natural  size.)   ^^^  extent  until  it  became  quite  soft  and  feeble.      At  this 

point  the  male  began  to  approach 


the  female,  uttering  a  series  of 
twittering  chirps;  the  female  ran 
away,  and  the  male,  after  a  short 
chase,  returned  to  his  old  haunt, 
singing  with   the  same  vigor,  but 


cricket,  Nemobius 
jasciatus;  form  vit- 
tatus, female.  (After 
Lugger;  about 
twice  natural  size.) 


Fig.  226.  — 
snowy  tree- 
cricket,  CEcan- 
thus  niveus. 


Fig.  227. — (Ecanihus  jasciatus,  female.     (After 
Lugger;    natural  size  indicated  by  line.) 


i6o    Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 


with  more  frequent  pauses.     At  length  finding  all  persuasions  unavailing,  he 
brought  his  serenade  to  a  close." 

From  midsummer  till  frost  comes  there  is  a  shrill  insistent  night-song 
that  makes  familiar  an  insect  rarely  seen  except  by  persistent  students. 
X-r-r — r-e-e;  t-r-r — r-e-e,  repeated  without  pause  or  variation  about  seventy 
times  a  minute:  this  is  the  song  of  the  snowy  tree-cricket,  or  white  climbing 
cricket,  (Ecantheics  niveus  (Fig.  226),  common  all  through  the  East  and 
Middle  West.  These  crickets  differ  much  from  the  better  known  robust, 
black-brown  house-  and  field-crickets  in  shape  and  color;  the  body  is 
about  one-half  inch  long,  slender,  and  the  long  wing-covers  are  so  held, 
when  the  insect  is  at  rest,  that  the  back  (including  the  wing-covers)  is  widest 

behind  and  tapers  forward  to  the 
small  narrow  head.  The  body  is 
ivory-white  tinged  with  delicate 
green,  and  the  wing-covers  and 
wings  are  clear.  The  antennae  are 
extremely  long  and  thread-like  and 
have  two  slightly  elevated  black 
dots  on  the  under  side,  one  on  the 
first  segment  and  one  on  the  second. 
The  females  do  much  harm  by 
their  habit  of  cutting  slits  in  the 
tender  canes  or  shoots  of  raspberry, 
grape,  plum,  peach,  for  their  eggs. 
The  cane  or  shoot  often  breaks  off 
at  the  place  where  the  eggs  are 
deposited,  and  by  collecting  these 
in  the  late  autumn  or  winter  and 
burning  them  many  eggs  will  be 
destroyed.  Several  other  species 
of  (Ecanthus  are  found  in  this 
country;  one,  O.  jasciatiis  (Figs.  227  and  228),  with  three  black  stripes  on 
head  and  prothorax  and  usually  dark  body,  is  common  in  the  Mississippi 
Valley,  and  a  third  species,  O.  angustipennis,  with  wing-covers  just  one- 
third  as  wide  in  broadest  part  as  their  length,  is  less  common. 

Occasionally  one  finds  on  the  ground,  or  more  likely  in  digging,  a  curious 
flattened,  light  velvety  brown  insect  about  an  inch  and  a  half  long,  with 
the  fore  feet  much  widened  and  strangely  resembling  those  of  the  common 
mole,  and  altogether  having  an  appearance  strange  and  unlike  that  of  any 
other  insect.  This  is  a  burrowing,  or  mole,  cricket,  which  burrows  beneath 
the  soil  in  search  of  such  food  as  the  tender  roots  of  plants,  earthworms, 
and  the  larvae  of  various  insects.     Its  eyes  are  also  like  those  of  the  mole, 


Fig.  228.  Fig.  229. 

Fig.  228. — (Ecanthus  fasciati4S,  rrnde.     (After 

Lugger;    natural  size  indicated  by  line.) 
Fig.  229. — Orocharis  saltator,  fermle.     (After 

Lugger;    natural  size  indicated  by  line.) 


Cockroaches,  Locusts,  Grasshoppers,  and  Crickets    1 6 1 


much  reduced,  being  nearly  lost,  and  as  this  cricket  crawls  rather  than 
leaps,  the  hind  or  leaping  legs  are  not  so  disproportionately  larger  than  the 
others  as  in  the  above-ground  crickets.  The  males  make  a  sharp  chirping 
loud  enough  to  be  heard  several  rods  away.  The  common  species,  called 
the  northern  mole-cricket,  Gryllotalpa  borealis,  has  the  wing-covers  less  than 
half  the  length  of  the  abdomen,  while  the  wings  extend 
only  about  one-sixth  of  an  inch  beyond  them.  A  less 
common  species,  G.  Columbia,  the  long- winged  mole- 
cricket,  has  the  hind  wings  extending  beyond  the 
tip  of  the  abdomen.  The  mole-crickets  like  rather 
damp  places  near  ponds  or  streams,  where  they  make 
channels  with  raised  ridges  which  resemble  miniature 
mole-hills.  These  "runs"  usually  end  beneath  a  stone 
or  small  stick.  The  insects  are  infrequently  seen,  as 
they  remain  mostly  underground,  only  occasionally 
coming  out  at  night.  The  female  deposits  from  two 
hundred  to  three  hundred  eggs  in  masses  of  from 
forty  to  sixty  in  underground  chambers,  and  the  young 
are  about  three  years  in  reaching  maturity.  When 
present  in  any  region  in  large  numbers  mole-crickets   Fig.    230. —  The  Porto 

become  seriously  destructive  because  of  their  attacks       ^ican      molc-cncket, 

bcapteriscus     didacty- 
on  plant-roots.     In  Porto  Rico  a  mole-cricket,  Scap-       lus.      (After   Barrett; 

teriscus  didadylus  (Fig.  230),  called  "changa,"  dam-       natural  size.) 

ages  tobacco,   sugar-cane,    and    small    crops    to    the   value  of   more  than 

$100,000  annually  and  is  by  far  the  most  serious  insect 

pest  in  the  island. 

Much   smaller  than   the  true  mole-crickets  are  the 

pygmy,   burrowing  crickets  of  the  genus   Tridactylus, 

of  which   several   species  occur  in  the   United   States. 

The  largest    species,   T.   apicalis   (Fig.   231),  is  about 

J  inch  long.     They  resemble  the  mole-crickets  in  general 

body  characters,  but  are  more  brightly  colored,  and  the 

fore  feet,  although  broad  and  flat  for  digging,  differ  in 

being  curiously  armed  at  the  end  with  three  spurs;  hence 

Fig.  27,1  —Tridactylus   ^]^g  oreneric  name.     They  can  leap  amazingly,  so  that 
apicahs.        (After''  .  .  ■'  ^  ^^' 

Lugger;  natural  size   they  seem,  on  jumping,  to  disappear  most  mysteriously, 

indicated  by  line.)       the  eye  not  being  able  to  follow  them  in  the  air. 
The  most  aberrant  of  all  the  crickets  are  the  tiny  flat  and  broad-bodied 
species   of   the  genus   Myrmecophila,  which  live   as   commensals   or  mess- 
mates in  the  nests  of  ants.     They  are  found  only  in  ants'  nests,  have  no 
compound  eyes,    and  the   hind   femora   are   much    swollen   and   enlarged. 


i62    Cockroaches,  Locusts,  Grasshoppers,  and  Crickets 


The  semi-parasitic  life  which  they  lead  has  resulted  in  such  a  change  of 
habits  that  their  body  is  modified  very  far  from  the  normal  cricket  type. 
The  commonest  species  is  Myrmecophila  nebrascensis,  about  -j\  inch  long, 
shown  in  Fig.  232. 

Formerly  included  in  the  order  Orthoptera,  the  earwigs  are  now  recog- 
nized as  entitled  to  distinct  ordinal  rank,  and  the  thirty  or  more  genera  in 
the  world,  of  which  but  six  occur  in  the  United  States, 
are  held  to  constitute  the  order  Euplexoptera.  This 
order  is  closely  related  to  the  Orthoptera,  although  the 
insects  themselves  look  more  like  beetles. 

The  earwigs  are  small,  brownish  or  blackish  insects, 
readily  recognized  by  the  curious  forceps-like  appendages 
on  the  tip  of  the  abdomen  (Fig.  233).  They  are  either 
winged  or  wingless,  but  when  winged  have  small  leath- 
ery wing-covers  only  extending  about  half-way  to  the 
tip  of   the   abdomen,   with  the    well-developed    nearly 

T?Tp  2  2  2    A^  V  f  fft  C" 

cophila  nebrascensis,  a  hemispherical  wings  compactly  folded,  both  longitudi- 
degenerate  cricket  nally  and  transversely,  underneath  them.  Earwigs  are 
times  "^ot  often  seen  because  they  are  nocturnal  in  habit, 
but  in  some  places  they  are  rather  abundant.  They 
are  ve<^etable  feeders,  being  especially  fond  of  ripe  fruit,  flower  corollas,  etc., 
which  they  bite  off  and  chew  with  the  well-developed  jaws  and  maxilla?. 
The  female  lays  her  small,  yellowish  oval  eggs  in 
small  masses  under  fallen  leaves  or  in  other  con- 
cealed places,  and  is  said  to  nestle  on  them  as  a 
hen  on  her  eggs.  She  is  also  said  to  protect  the 
young  for  some  time  after  they  are  hatched.  The 
young  undergo  an  incomplete  metamorphosis,  de- 
veloping wings  externally,  and  resembling  the 
parents,  except  in  size,  from  the  time  of  their 
hatching. 

The  commonest  representative  of  the  order  in  the 
northern  and  eastern  states  is  the  little  earwig. 
Labia  minor  (Fig.  233),  measuring  to  tip  of  forceps  only  about  J  inch. 
Other  American  species,  as  Labidura  riparia,  a  Florida  species,  brownish 
yellow  with  a  pair  of  longitudinal  black  stripes  on  prothorax  and  wing- 
covers,  with  long  slender  forceps,  and  Anisolabis  annulipes,  a  black  wingless 
California  species  with  short  heavy  forceps,  are  larger,  these  two  species 
being  a  Httle  more  and  a  little  less  than  |  inch  respectively. 


that  inhabits 
nests.  (Five 
natural  size.) 


Fig.  233.  —  An  earwig, 
Labia  minor.  (Six  times 
natural  size.) 


CHAPTER  X 


THE  TRUE  BUGS,  CICADAS,  APHIDS,  SCALE- 
INSECTS,  ETC.  (Order  Hemiptera),  AND  THE 
THRIPS  (Order  Thysanoptera) 


W 


HEN  an  Englishman  says  "bug"  —  and 
he  doesn't  say  it  in  polite  society — he 
means  that  particular  sort  of  bug  which 
we  more  specifically  speak  of  as  bedbug; 
when  we  say  "bug"  we  are  likely  to  mean  any  insect 
of  any  order;  but  when  a  professed  student  of  insects, 
an  entomologist,  says  or  writes  bug,  he  means  some 
member  of  the  insect  order  Hemiptera.  It  is  to  this 
order  of  "bugs"  that  we  have  now  come  in  our  system- 
atic consideration  of  insects,  and  it  is  in  this  order  that 
we  first  meet  conspicuously  the  difficulties  of  treating 
systematically  the  populous  insect  class.  From  now 
on  the  making  of  this  book  useful  depends  on  the  discriminating  selection 
of  the  few  kinds  of  insects  whose  special  consideration  the  limits  of 
text  and  illustration  permit,  leaving  the  great  majority  of  species  to  be 
referred  to  comprehensively  and  vaguely  as  the  "others." 

The  Hemiptera,  or  true  bugs,  make  up  a  large  order  compared  with  any 
of  those  so  far  considered,  although  a  smaller  one  than  certain  others  yet  to  be 
taken  up.  As  regards  popular  acquaintanceship  and  interest  also  this 
order  is  still  more  inferior  to  the  other  large  ones,  namely,  the  beetles,  the 
moths  and  butterflies,  the  two-winged  flies,  and  the  ants,  bees,  and  wasps. 
Most  of  the  true  bugs  are  small,  and  obscurely,  or  at  least  inconspicuously, 
colored,  and  few  of  them  attract  that  attention  necessary  to  gain  popular 
interest. 

The  order  Hemiptera  includes  over  5000  known  species  of  North 
American  insects,  representing  a  large  variety  and  a  great  economic  impor- 
tance; some  of  the  most  destructive  crop  pests  and  most  discomforting  insect- 
scourges  of  man  and  the  domestic  animals  belong  to  this  order.  The 
chinch-bug's  lavages  in  the  corn-  and  wheat-fields  of  the  Mississippi  Valley 
offer  effective  evidence  to  the  dismayed  farmers  of  the  workings  of  a  dis- 
pleased Providence;    the  tiny  sap-sucking  aphids  and  phylloxera  and  insig- 

163 


I 

I 


164  Bugs,  Cicadas,  Aphids,  and  Scale-insects 


nificant-looking  scale-insects  make  the  orchardist  and  vine-grower  similar 
believers  in  supernatural  moral  correction  by  means  of  insect -scourges, 
and  the  piercing  and  sucking  lice  and  bugs — in  the  English  meaning — make 
personal  and  domestic  cleanliness  a  virtue  that  brings  its  own  immediate 
reward. 

Other  not  unfamiliar  representatives  of  this  order  are  the  loud-singing 
cicadas  with  their  extraordinarily  protracted  adolescence,  the  thin-legged 
water-striders  and  skaters  of  the  surface  of  pond  and  quiet  trout-pool,  the 
oar-legged  water-boatmen  and  back-swimmers  of  the  depths  of  the  same 
pools,  the  ill-smelling  squash-bugs,  calico-backs,  and  stink-bugs  of  the 
kitchen-gardens,  the  big,  flat-bodied,  electric-light  or  giant  water-bugs  that 
,  whirl  like  bats  around  the  outdoor  arc-lights, 

and  the  assassin-  and  "kissing "-bugs  of  one- 
time newspaper  interest.  In  structure  all  the 
Hemiptera  agree  in  having  the  mouth-parts 
formed  into  a  piercing  and  sucking  beak  (Fig. 
234)  capable  of  taking  only  liquid  food.  As 
that  food  is  nearly  always  the  blood  of  living 
animals  or  the  sap  of  living  plants,  the  nearly 
uniformly  injurious  or  distressing  character  of 
the  food-habits  of  all  the  members  of  the 
order  is  apparent.  This  beak  is  composed 
of  the  elongate,  tubular  under-lip  (labium) 
acting  as  sheath  for  the  four  slender,  needle- 
like piercing  stylets  (modified  mandibles  and 
maxillae).  The  labium  is  not  a  perfect  tube, 
for  it  is  narrowly  open  all  along  its  dorso- 
medial  line,  but  the  edges  of  this  slit  can  be 
brought  closely  together  and  the  slit  also 
covered  internally  by  the  stylets,  so  that  an 
effective  tubular  sucking  proboscis  is  formed 
(Fig.  14).  The  name  Hemiptera  is  derived  from 
the  character  of  the  fore  wings  shown  by  most, 
though  by  no  means  all,  of  the  members  of  the 
order;  this  is  the  thickening  of  the  basal  half  of  the  otherwise  thin, 
membranous  wing,  so  that  each  fore  wing  is  made  up  of  two  about  equal 
parts  of  obviously  different  texture  and  appearance;  hence  "half-winged" 
(Fig.  268).  All  Hemiptera  (excepting  the  male  scale-insects)  have  an  incom- 
plete metamorphosis,  the  young  at  birth  resembling  the  parents  in  most  essen- 
tial characteristics  except  size  and  the  presence  of  wings.  By  steady  growth, 
with  repeated  moultings  and  the  gradual  development  of  external  wing- 
pads,  the  adult  form  is  reached,  without  any  of  the  marked  changes  apparent 


Fig.  234. — Diagram  of  section 
through  head  and  basal  part 
of  beak  of  a  sucking-bug. 
ph.,  pharynx;  m.,  muscles 
from  pharynx  to  dorsal  wall 
of  head;  •y.,  valve;  5.,  stop- 
per; m.,  muscle  of  stopper; 
s.d.,  salivary  duct;  Ir.,  la- 
brum;  b.,  one  of  the  stylets 
of  beak.  To  pump  fluid  up 
through  the  beak,  the  mus- 
cle attached  to  the  stopper 
contracts,  thus  expanding  the 
cavity  closed  by  the  valve. 
(After  Leon.) 


Bugs,  Cicadas,  Aphids,  and  Scale-insects  165 

in  the  insects  of  complete  metamorphosis.  With  similar  mouth-parts  the 
young  have,  in  most  cases,  similar  feeding  habits,  preying  on  the  same  kinds 
of  plants  or  animals  that  give  nourishment  to  the  parents. 

The  extent  of  the  injuries  done  by  various  members  of  this  order  to 
farm  and  orchard  crops,  to  meadov^s  and  forests,  and  to  our  domestic 
animals  is  enormous.  Of  the  other  insects  the  order  of  beetles  includes 
numerous  crop  pests,  and  the  caterpillars  of  many  moths  and  a  few  butter- 
flies do  much  damage;  locusts  have  a  healthy  appetite  for  green  things, 
and  many  kinds  of  flies  could  be  lost  to  the  v^^orld  to  our  advantage,  but 
perhaps  no  other  order  of  insects  has  so  large  a  proportion  of  its  members 
in  the  category  of  insect  pests.  The  single  Hemipterous  species,  Blissus 
hiicopterus,  better  known  by  its  vernacular  name  of  chinch-bug,  causes 
an  annual  loss  to  grain  of  twenty  millions  of  dollars;  the  grape  phylloxera 
destroyed  the  vines  on  3,000,000  acres  of  France's  choice  vineyards;  the 
San  Jose  scale  has  in  the  last  ten  years  spread  from  California  to  every 
other  state  and  territory  of  the  United  States  and  become  a  menace  to  the 
whole  fruit-growing  industry.  So,  despite  their  small  size  and  their  general 
unfamiliarity  to  laymen,  the  Hemiptera  are  found  by  economic  entomologists, 
in  their  warfare  against  the  insect-scourges  of  the  country,  to  be  one  of  the 
most  formidable  of  all  the  insect  orders. 

The  classification  of  the  Hemiptera  into  subgroups  is  a  matter  Hkely 
to  prove  difficult  for  the  amateur  and  general  collector.  The  order  as  repre- 
sented in  our  country  includes  thirty-nine  families,  and  the  structural  char- 
acters separating  some  of  these  families  are  slight  and  not  easily  made  out  by 
untrained  students.  For  the  use,  however,  of  readers  of  this  book  capable 
of  using  them,  keys  or  tables  of  all  the  families  of  the  Hemiptera  are  presented. 
For  more  general  use,  however,  I  shall  try  to  arrange  the  families  in  groups 
depending  on  the  habits  and  more  obvious  appearance  and  make-up  of  the 
insects,  characteristics  which  may  be  readily  noted.  And  this  arrange- 
ment will  not  be  less  "scientific"  than  the  arrangement  in  the  key  com- 
monly used  by  entomologists,  as  the  latter  is  confessedly  largely  artificial 
and  convenient  rather  than  natural  in  its  groupings. 

The  order  is  separable  into  three  primary  natural  groups  or  sub-orders 
as  follows: 

Wingless  forms,  with   a  fleshy,  unsegmentcd  sucking-beak,  living    as  parasites  on 

man  and  other  mammals Parasita. 

Winged,  or  sometimes  wingless,  but  always  with  the  beak  segmented. 

Wings  of  the  same  texture  throughout  and  usually  held  sloping  or  roof-like 
over  the  back  and  sides  of  the  body;  sucking-beak  arising  from  the 
hinder  part  of  the  lower  side  of  the  head;  tne  head  so  closely  joined 
to  the  prothorax  that  the  bases  of  the  fore  legs  touch  the  sides  of  the 
head Homoptera. 


1 66         Bugs,  Cicadas,  Aphids,  and  Scale-insects 

Fore  wings  with  basal  half  thickened  and  parchment-like,  apical  half  thin 
and  membranous;  the  four  wings  lying  flat  on  the  back  when  folded, 
the  membranous  tips  overlapping;  sucking-beak  arising  from  the 
front  part  of  head,  and  the  head  usually  separated  from  the  pro- 
thorax  by  a  m.ore  or  less  distinct  neck Heteroptera. 

Of  these  three  suborders  the  Parasita,  or  sucking-Hce,  are  degenerate 
wingless  species  and  will  be  considered  last.  The  Heteroptera  include 
the  so-called  "true  bugs"  with  fore  wings  thickened  at  base,  and  when 
folded  lying  fiat  on  the  back,  as  the  squash-bug,  chinch-bugs,  and  the  great 
majority  of  the  species  in  the  order,  while  the  Homoptera  include  the  cicadas, 
the  tree-  and  leaf-hoppers,  the  aphids  or  plant-lice,  the  mealy-winged  flies, 
and  the  degenerate  scale-insects. 

SUBORDER  HOMOPTERA. 

Key  to  Families  of  the  Homoptera  (includes  both  Nymphs  and  Adults). 

(Adapted  from  Woodworth.)  * 

Proboscis  seeming  to  rise  from  the  middle  of  the  sternum,  or  proboscis  wanting;   insects 
less  than  J  inch  long. 

Hind  femora  much  larger  than  other  femora (Jumping  plant-lice)     Psyllid.e. 

Hind  femora  not  much  larger  than  the  others. 

Legs  long  and  slender (Plant-lice.)     Aphidiid.?;. 

Legs  short,  or  wanting. 

Feet  of  one  joint,  or  wanting (Scale-insects.)     Coccid^. 

Feet  of  two  joints (Mealy  wings.)     Aleyrodid.^:. 

Proboscis  plainly  arising  from  the  head. 

With  three  ocelli,  sometimes  (nymphs)  with  large  front  tibiae  and  no  wings. 

(Cicadas.)     Cicadid^. 
With  two  ocelli  or  none,  and  the  front  tibiae  not  enlarged. 

Antennae  inserted  on  head  below  the  eyes (Lantern-flies.)     Fulgorid.e. 

Antennae  inserted  in  front  of  and  between  the  eyes. 

Prothorax  extending  back  over  the  abdomen (Tree-hoppers)     Membracid^.   ^ 

Prothorax  not  extending  back  over  the  abdomen. 

Hind  tibiae  with  few  spines (Spittle-insects.)     CERCOPiD.aE.  <3 

Hind  tibse  with  two  rows  of  spines (Leaf-hoppers.)     Jassid^.  ^ 

Perhaps  no  other  insect-species  has  any  single  characteristic  of  its  hfe- 
history  of  the  same  interest  as  the  extraordinarily  long  duration  of  the  adoles- 
cence of  the  seventeen-year  cicada.  That  a  single  one  of  the  300,000  and 
more  known  species  of  insects  should  have  a  period  of  development  from 
egg  to  adult  of  more  than  sixteen  years,  while  this  period  in  all  other  insects 
varies  from  a  few  days  to  not  more  than  three  years — comparatively  few 
insects  live,  all  told,  more  than  a  year — is  perhaps  the  most  striking  excep- 
tional fact  in  all  insect  biology.  The  other  members  of  the  family 
Cicadidae,  to  which  this  insect  belongs,  have,  as  far  as  known,  an  immature 


Bugs,  Cicadas,  Aphids,  and  Scale-insects         167 


life  of  but  one  or  two  years.  But  few  species  of  cicadas,  dog-day  locusts, 
harvest-flies,  or  lyremen,  as  they  are  variously  called,  occur  in  this  country 
— they  are  more  abundant  in  subtropic  and  tropic  countries — but  their 
large,  robust,  blunt-headed  body,  their  shrill  singing  and  their  wide  dis- 
tribution make  them  familiar  insects. 
In  summer  and  fall  the  piercing, 
rhythmic  buzzing  of  the  cicadas  comes 
from  the  trees  from  early  morning 
till  twilight.  The  song,  unlike  that 
of  the  katydids  and  tree-crickets,  is 
hushed  at  night.  The  sound  is  made, 
not  by  a  rasping  together  of  wings 
or  legs,  but  by  stretching  and  relaxing 
a  pair  of  corrugated  tympana,  or 
parchment-like  membranes,  by  means 
of  a  muscle  attached  to  the  center 
of   each;    much,   indeed,  as   a    small 

boy  makes  music  from  the  bottom  of    Fig.  235.  —  The    seventeen-year    cicada, 
.,,  .   •        r     .        J  J.     -.  Cicada    septendecim;    specimen    at    left 

a  tm  pan  with  a  strmg  fastened  to  its  growing  sound-making  organ,  v.p., 
center.  These  sound-making  organs  ventral  plate;  /.,  tympanum.  (Natural 
of  the  cicadas,  confined  to  the  males —       ^^^^'' 

"Happy  is  the  cicada,  since  its  wife  has  no  voice,"  says  Xenarchos — are 
situated  in  resonance-cavities  or  open  boxes,  furnished  with  other  sym- 
pathetically vibrating  membranes,  at  the  base  of  the  abdomen  (Figs.  235 
and  236).     The  sound-chambers  are  incompletely  closed  (wholly  open  in  the 

seventeen-year  cicada)  by  a  pair  of  semicircular 
disks,  which  are  opened  or  shut  by  move- 
ments of  the  body  so  as  to  give  the  song  a 
peculiar  rhythmic  increase  and  decrease  of 
loudness. 

The  cicada  that  is  most  familiar,  and.on  hand 
every  summer  over  most  of  the  country,  is  the 
large  (2  inches  in  length  to  tip  of  closed  wings) 
black  and  green  dog-day  harvest-fly,  Cicada 
tibicen.  The  life-history  of  this  species  is  not 
fully  known,  but  the  insect  requires,  accord- 
ing to  Comstock,  two  years  to  t^ecome  mature. 
The  really  famous  cicada  is  Cicada  septen- 
decim, the  seventeen-year  locust,  or  periodical  cicada  (Fig.  235).  It  is 
about  li  inches  long,  black,  banded  with  red  on  the  abdomen,  and  with 
bright  red  eyes  and  the  veins  of  both  wings  red  at  the  base  and  along  the 
front  margin.     The  females  lay  their  eggs  in  early  summer  in  slits  which 


Tig.  236. — Diagram  of  section 
of  body  of  cicada,  showing 
attachment  of  muscles  to  inner 
surface  of  sound-making 
organ.     (Enlarged.) 


I  68         Bugs,  Cicadas,  Aphids,  and  Scale-insects 

they  cut  with  the  sharp  ovipositor  in  the  twigs  of  various  trees,  in  this  way 
often  doing  much  damage  to  orchards  and  nurseries.  The  young  hatch 
in  about  six  weeks  and  drop  to  the  ground,  where  they  burrow  down  through 
cracks  and  begin  their  long  underground  life.  They  feed  on  the  humus 
in  the  soil  and,  to  some  extent,  on  juices  sucked  from  the  tree-roots.  They 
grow  slowly,  moulting  probably  four  or  six  times  at  intervals  of  from 
two  years  to  four  years.  In  spring  or  early  summer  of  the  seventeenth 
year  (thirteenth  in  a  race  in  the  southern  states)  they  come  above  ground, 
and,  after  hiding  for  a  while  under  stones  and  sticks,  crawl  up  on  the  trunks 
of  trees  and  there  moult  for  the  last  time,  the  winged  adult  emerging  and 
soon  flying  into  the  tree-tops.  The  various  broods  or  swarms  in  this  country, 
about  twenty  in  number,  are  known,  and  the  territory  occupied  by  each 
has  been  mapped,  so  that  it  is  possible  for  entomologists  to  predict  the 
appearance  of  a  swarm  of  seventeen-year  cicadas  in  a  particular  locality 
at  a  particular  time.  As  all  the  members  of  one  of  these  swarms  issue  in 
the  same  season,  and  indeed  in  the  same  month  or  fortnight,  they  usually 
attract  much  attention.  The  broods  to  issue  in  the  next  few  years  are  the 
following:  a  large  one  in  1905  in  the  northern  half  of  Illinois,  eastern  part 
of  Iowa,  southern  part  of  Wisconsin,  southern  edge  of  Michigan,  and  northern 
and  western  edge  of  Indiana;  a  scattered  one  in  igo6  ranging,  not  contin- 
uously, from  Massachusetts  south  and  west  through  Long  Island,  New 
Jersey,  Pennsylvania,  Maryland,  West  Virginia,  Ohio,  Indiana,  Kentucky, 
Tennessee,  North  and  South  Carolina,  and  northern  Georgia;  and  a  large 
one  in  1907,  ranging  from  central  Illinois  south  and  east  to  the  Gulf  and 
Atlantic. 

A  considerable  number  of  small  insects,  often  seed-like  in  shape,  or 
with  the  thorax  prolonged  into  odd  horns,  spines,  or  crests,  are  included 
in  the  families  of  tree-hoppers  (Membracidae)  and  lantern-flies  (Fulgoridse) 

(Fig.  237).  Striking  members,  large  and  bright- 
colored,  of  this  latter  family  are  found  in  the 
South  American  tropics,  but  the  North  American 
species  are  small,  and  are  rarely  seen  or  collected 

FiG_  237. A  fulgorid,  Stohera    by  amateurs.     Among  the  commonest  of  our  forms 

tricarinata.   (After  Forbes;    are   the   candle-heads,  species   of   Scolops,  small 

natural  length   1   inch.)  .  .      t    •  j  u     u  -i-i.   4.u     u      j 

msects  livmg  on  grass  and  herbage,  with  the  head 
bearing  a  long  slender  upcurving  projection.  The  tree-hoppers  (Mem- 
bracidae) almost  all  suggest  small  angular  brownish  seeds  or  thorns  in  shape 
and  color.  The  prothorax  is  sometimes  widely  expanded,  sometimes 
lengthened  so  as  to  cover  nearly  the  whole  body,  sometimes  humped  or 
crested,  sometimes  spined  or  pitted.  The  unusual  form  is  probably  pro- 
tective, making  the  insects  simulate  seeds  or  other  plant  structures.  The 
species  of  Enchenopa  (Fig.  239)  are  curiously  horned.    E.  hinotata  is  common 


Bugs,  Cicadas,  Aphids,  and  Scale-insects         169 

in  the  east.  It  is  gregarious  and  is  attended  by  ants  which  feed  on  a  sweetish 
substance  excreted  by  it.  It  lays  its  eggs  in  Httle  white  waxen  frothy  masses. 
A  curiously  humpbacked  form  is  Senilia  camelas  (Fig.  240).     The  best  known 

and  most  injurious  tree-hoppers  are  those 
of  the  genus  Cerasa,  of  which  the  species 
^C.  bubalus,  or  buffalo  tree-hopper  (see  initial 
letter  of  this  chapter),  injures  fruit-trees 
both    by   piercing  and   sucking  sap   from 


.n^. 


::■   ,nw^ 


Fig.  238.  Fig.  239.  Fig.  240. 

^  Fig.   238. — The  black-backed  tree-hopper,  Arthasia    galleata.      (After  Lugger;    natural 

length  I  inch.) 
'  Fig.  239. — A  tree-hopper,  Enchenopa  gracilis.     (Three  times  natural  size.) 
^  Fig.  240. — A  tree-hopper,  Senilia  camelas.     (Three  times  natural  size.) 


them,  and  by  making  slits  in  the  twigs  to  lay  eggs  in.  It  is  about  ^  inch 
long,  light  grass-green  with  whitish  dots  and  a  pale  yellowish  streak  on 
each  side.  On  the  front  there  are  two  small  sharp  processes  jutting  out  one 
on  each  side  from  the  prothorax,  and  suggesting  a  pair  of  horns,  hence 
the  name.  It  is  common  on  apple  and  many  other  trees  from  the  middle 
of  summer  until  late  in  the  autumn.  The  eggs  are  laid  in  pairs  of  nearly 
parallel  and  slightly  curved  slits.  The  young  hatch  in  the  spring  following 
egg-laying. 

Walking  over  our  lawns  or  through  pastures  and  meadows  we  often 
startle  from  the  grass  hundreds  of  small,  usually  greenish,  little  insects  that 
leap  or  fly  for  a  short  distance,  but  soon  settle  again  in  the  herbage.  Nearly 
all  these  smiiU  and  active  insects  are  sap-sucking  leaf-hoppers,  of  the  family 
Jassidas,  one  of  the  largest  and  most  injurious  of  the  Hemipterous  families. 
It  is  stated  by  careful  students  of  these  grass-pests  that  from  nearly  one- 
fourth  to  one-half  of  all  the  grass  springing  up  annually  is  destroyed  by 
leaf-hoppers.  Professor  Osborn  estimates  that  over  one  million  leaf-hoppers 
can  and  often  do  live  on  an  acre  of  grass-covered  ground.  These  insects 
are  rarely  more  than  J  inch  long,  and  most  of  them  are  nearer  half  of  that. 
The  body  is  more  slender  than  in  the  tree-hoppers,  and  is  usually  widest 
across  the  prothorax  or  a  Httle  behind  it,  tapering  back  to  the  tip  of  the 
folded  wings.  The  head  is  more  or  less  triangular,  as  seen  from  above, 
and  the  face  is  oblique,  sloping  back  to  the  base  of  the  fore  legs.  The 
family  is  a  large  one,  containing  many  species,  of  which  several  are  well 


170         Bugs,  Cicadas,  Aphids,  and  Scale-insects 


known  to  economic  entomologists  as  special  pests  of  grasses,  growing  grain, 
grapes,  roses,  etc.  The  injury  is  caused  by  the  draining  away  of  the 
sap  of  the  plant  by  the  host  of  little  sucking-beaks  thrust  into  its  leaves 
or  stem.  Among  the  notorious  destructive  species  are  the  destructive  leaf- 
hopper,"^  CicaJn/a  exitiosa,  i  inch  long,  brownish,  which  often  injures 
seriously  the  winter  wheat  of  the  southern  states.  Also  the  various 
grape-leaf  hoppers,  which  cause  the  leaves  of  grape-vines  to  wilt  and  turn 
brown  and  prevent  the  formation  of  full  grapes;  one 
of  these,  Erythroneura  vitis,  is  about  ^  inch  long, 
crossed  by  two  blood-red  bands  and  a  third  dusky 
one  at  the  apex.  I  have  seen  millions  of  individuals 
oi^Erythroneura  comes  (Fig.  242)  in  the  great  3300- 
acre  vineyard  of  the  Vina  Ranch  in  the  Sacramento 
Valley  of  California.  These  leaf-hoppers  hibernate 
in  the  vineyard  or  about  its  edges  under  fallen 
leaves  and  rubbish.  Probably  the  best  remedy  for 
them  is  to  keep  the  vineyards  as  clean  as  possible, 
.1    or  at  least  to  burn  up  in  the  winter  any  accumulated 

rubbish.  The  rose  leaf-hop- 
per, '  Tr^/z/or^'Zja  rosa,  is 
often  abundant  on  rose- 
bushes, and  also  on  apple- 
trees.  The  eggs  are  laid  in 
the  summer,  and  the  young 
develop  through  the  summer 
and  fall,  hibernating  as 
adults  under  leaves  or  rub- 
bish. 


A  common  leaf-hop- 


FiG.  241.  Fig.  242. 

Fig.  241. — The  celery  leaf -hopper,  Cicadula  4-Uneata. 

(After  Lugger;  natural  size  indicated  by  line.) 
Fig.  242. — Two    vine-hoppers,    at     left    Erythroneura  _ 

viilnerata,  on  right^£.  comes.     (After  Forbes;  much  per  of  grass-fields  is'  Diedro- 

en  arge  .  j  cephala  molHpes,  ^  inch  long, 

spindle-shaped,  grass-green   above,  pale  yellowish   below,  with  black  lines 

across  the  face  and  top  of  head,  and  the  fore  wings  with  bluish  veins  and 

yellowish  edges. 

Occasionally  one  finds  frothy,  spittle-like  masses  adhering  to  the  stems 
of  weeds  or  shrubs  in  which  may  be  found  imbedded  one  or  more  odd- 
shaped,  squat,  slant-faced  insects  from  -j\  inch  to  ^  inch  long  (Fig.  243). 
These  are  the  young — they  have  no  wings,  only  wing-pads  or,  if  very  young, 
not  even  these — of  the  spittle-insects  or  frog-hoppers,  family  Cercopidae. 
The  spittle  is  a  viscid  fluid  expelled  from  the  alimentary  canal  of  the  insects, 
and  beaten  up  into  a  froth  by  the  whisking  about  of  the  body.  What 
advantage  it  is  to  the  young  insects  is  hard  even  to  conjecture;  it  certainly  is 
not  known.     The  adult  frog-hoppers — this  name  is  derived  from  a  popular 


Bugs,  Cicadas,  Aphids,  and  Scale-insects         171 


belief  that  the  spittle  is  that  of  tree-frogs — are  small  flattish,  brownish  or 

grayish   insects  about  -3-   inch   long  which  occasionally  occur  in   sufficient 

numbers  to  do    some    injury    to  grapes, 

cranberries,  or  pasture  grasses.     A  grape 

frog  -  hopper,  ^yl/j/^ro/'/zora    ^-notata,    has 

brown    wing-covers  with    three    blackish 

spots  on  each;    another  found  on  grapes 

in  the  east,  A.  signoreti,  is  tawny  brown 

clouded  with  dull  white  and  thickly  dotted 

with  black  spots;    the   cranberry  spittle- 

insecf;  Clastoptera  protens,  which   occurs 

on  cranberries  and  blueberries  in  marshes, 

is  black,  with  two  yellow  bands   on  top 

of   the    head,   one    in   the    thorax,    two 

oblique    stripes  on   the   base  of  the  fore 

wings,  and  a  cross-bar  near  the  tip;    C. 

pini  is  a  small  shining  black  species  with 

pale  yellow  head  with  black  band  at  front 

margin,  that  occurs  on    the    needles  of 

pine-trees. 

Looking  like  miniature  cicadas,  but 
belonging  to  a  diiTerent  family,  and  really 
more  nearly  related  to  the  aphids  or  true 
plant-lice,  are  the  Psyllidae,  or  jumping 
plant-lice.  They  are  not  more  than  \  inch  long,  their  hind  legs  are 
enlarged  for  leaping,  some  of  them  exude  honey-dew,  as  the  true  plant- 
lice  and  the  scale-insects  do,  and  some  make  galls  on  the  wings  of  hack- 
berry  and  other  trees.  The  best-known  and  most  destructive  member  of 
the  family  is  the  pear-tree  flea-louse,  Psylla  pyricola.  This  is  a  minute 
insect  measuring  only  -^-^  inch  long  to  tip  of  folded  wings,  but  it  often  occurs 
in  such  large  numbers  in  pear-orchards  in  the  northeastern  and  northern 
states  as  to  destroy  extensive  orchards.  The  eggs  are  orange-yellow  and 
laid  on  the  leaves,  each  egg  having  a  lash-like  process  projecting  from  it. 
The  young  is  broad  and  flat  and  yellow  in  color,  growing  brownish  as  it 
grows  older.  The  adults  hibernate  in  crevices  in  the  bark  and  come  out 
in  spring  to  lay  their  eggs.  The  pests  can  be  killed  by  spraying  the  trees 
with  kerosene  emulsion  (see  p.  189),  immediately  after  the  leaves  have 
expanded  in  the  spring. 

A  very  important  and  very  interesting  family  is  that  of  the  Aphidiidae, 
the  plant-lice  or  aphis-flies  (Figs.  244  and  245).  The  species,  of  which 
there  are  many,  are  all  small,  \  inch  being  a  rarely  attained  maximum 
length.      The    most  familiar   representatives   of   the   family  are    the    tiny, 


■'^iigC. 


Fig.  243. — The  spittle-insect,  ApJiro- 
phora,  showing  stages  of  froth 
production.  (After  Morse;  en- 
larged.) 


172         Bugs,  Cicadas,  Aphids,  and  Scale-insects 


^  __    are 

Fig.    244;-The    southern    grain    plant-                 ^f    ^^  plant-lice    which    infest 

louse,   loxoptera    gramineum,   winged  ^ 
migrant.        (After 


plump-bodied,  pale-green  insects,  some  with  two  pairs  of  long,  delicate, 
transparent  wings,  some  without  wings,  common  on  flowers  in  conserva- 
tories and  gardens  and  known  as  "green  fly."  Other  often-noticed  kinds 
are  the  cockscomb  gall-louse  of  the  elm  and  the  "blights"  of  various  foliage 

trees,  as  alder-blight,  beech-blight,  elm- 
blight,  etc.,  these  "blight"  aphids  all 
secreting  conspicuous  white  woolly  masses 
of  wax  and  most  of  them  also  excreting 
honey-dew,  which  is  conspicuous  on  the 
leaves  and  on  the  sidewalks  under  the 
trees. 

Of    more    economic   importance 

plant 
ingec 
Pergande;    much   crop-plants,  the    extraordinarily  ruinous 
enlarged.)  grape-phylloxera,  for  example,  the  apple- 

tree  root-lou.se,  and  the  woolly  apple-aphis,  the  cherry-,  plum-,  and 
peach-aphids,  the  corn-root  louse,  the  hop-louse,  and  the  cabbage-aphis, 
turnip-louse,  and  other  aphid  pests  of  garden  vegetables.  All  of  these 
insects  are  minute  soft-bodied  defenceless  creatures,  which  effect  their  great 
injuries  to  their  host-plants  by  virtue 
of  great  numbers.  Fitch,  New  York's 
first  state  entomologist,  estimated  the 
number  of  cherry-aphids  that  were 
living  at  one  time  on  a  small  young 
cherry-tree  to  be  12,000,000.  Although 
uncounted  millions  of  the  toothsome 
juicy  little  aphid  bodies  are  being  con- 
stantly eaten  in  spring  and  summer  by 
eager  predaceous  insects,  such  as  lady- 
bird beetles,  certain  syrphid-fly  larva; 
and  aphis-lions  (larvae  of  lace-wing  and  hemerobius  flies),  just  as  constantly 
are  new  millions  being  produced  by  the  fecund  aphis  mothers,  most  of  the 
young  being  born  alive  and  requiring  but  a  few  days  to  complete  their 
growth  and  development,  and  to  be  ready  to  take  up  the  production  of 
young  themselves. 

Professor  Forbes  has  made  an  estimate  of  the  rate  of  increase  of  the  corn- 
root  louse  that  shows  this  great  fecundity.  A  single  stem-mother  of  the 
corn-root  aphis  produces  twelve  to  fifteen  young  that  mature  in  a  fortnight. 
"Supposing  that  all  the  plant-lice  descending  from  a  single  female  hatched 
from  the  egg  in  spring  were  to  live  and  reproduce  throughout  the  year,  we 
should  have  coming  from  the  egg  the  following  spring  nine  and  a  half  tril- 
lion young.     As  each  plant-louse  measures  about  1.4  mm.  in  length  and  .93 


Fig.  245. — The  southern  grain-louse, 
Toxoplera  gramineum,  wingless.  A, 
female;  B,  young  nymph;  C,  older 
nymph.  (After  Pergande;  much  en- 
larged.) 


Bugs,  Cicadas,  Aphids,  and  Scale-insects  173 


mm.  in  width,  an  easy  calculation  shows  that  these  conceivably  possil)le  de 
scendants  of  a  single  female  would,  if  closely  placed  end  to  end,  form  a  proces' 
sion  seven  million  eight  hundred  and  fifty  thousand 
miles  in  length;  or  they  would  make  a  belt  or  strip 
ten  feet  wide  and  two  hundred  and  thirty  miles  long." 
The  remarkable  plasticity  of  the  aphids  as  re- 
gards their  possession  or  lack  of  wings  and,  on  the 
physiological  side,  their  reproduction  agamically  or 
sexually,  introduces  certain  unusual  conditions  into 
their  life-history.  Although  each  species  is  likely 
to  present  idiosyncrasies  of  its  own,  a  fair  example 
of  the  course  of  aphid  life  through  a  season  may 
be  outlined  as  follows:  In  spring  there  hatch,  from 
eggs  which  have  been  laid  the  fall  before,  wingless 
females,  called  stem-mothers,  which  produce  young 
agamically  (i.e.,  from  unfertilized  eggs)  either  by 
giving  birth  to  them  in  active  free  condition  or  by 
laying  eggs.  From  these  eggs  hatch  wingless  females 
which  produce  in  turn  other  agamic  broods  of  wing- 
less females.  But  at  any  time  in  the  course  of  these 
successive  agamic  generations  either  all  or  a  part  of 
the  individuals  of  a  brood  may  be  winged,  and  these 
winged  females  fly  away  to  other  plants  and  there 
found  new  colonies  which  continue  the  series  of 
agamic  generations.  But  toward  the  end  of  the 
season,  when  the  first  cold  weather  announces  the 
approaching  winter,  broods,  still  parthenogenetically 
produced,  of  sexed  individuals,  both  males  and  fe- 
males appear.  "The  males  may  be  either  winged 
or  wingless,  but  these  true  females  are  always  wing- 
less." These  individuals  mate,  and  each  female 
produces  a  single  large  egg  which  passes  over 
the  winter  to  give  birth  in  the  following  spring  to  a 
wingless  stem-mother — that  one  which  begins  the 
spring  series  of  parthenogenetic  generations.  The  unfertilized  eggs,  called 
pseud-ova,  produced  in  numbers  by  the  spring  and  summer  agamic  mothers 
(from  which  eggs  the  young  frequently  emerge  while  the  eggs  are  still  in  the 
body  of  the  mother)  should  not  be  confused  with  the  single  fertilized  egg 
laid  in  the  late  fall  by  the  mated  females  of  the  sexed  generation.  Although 
these  two  sorts  of  eggs  are  alike  in  their  earliest  stages  in  the  ovaries  of  the 
females,  differences  very  soon  occur,  the  embryo  in  the  pseud-ovum  begin- 
ning to  develop  before  the  formation  of  its  own  egg  is  properly  completed. 


Fig.  246.  —  Bodies  of 
aphids  which  have  been 
killed  by  Hymenoptcr- 
ous  parasites,  the  adult 
parasitic  flies  having 
emerged  from  the  small 
circular  holes.  (En- 
larged.) 


174         Bugs,  Cicadas,  Aphids,  and  Scale-insects 


Characteristic  variations  in  the  general  course  are  described  later  in 
connection  with  the  accounts  of  the  few  particular  aphid  species  for  which 
we  have  place,  but  it  should  be  kept  in  mind  that  considerable  variations 
may  occur  in  the  case  of  a  single  species.  Extrinsic  influences,  such  as 
crowding  a  host-plant  and  hence  the  lessening  of  food,  or  an  unusual 
humidity  or  lack  of  humidity,  an  early  lowering  of  temperature  in  autumn, 
etc.,  seem  to  be  very  potent  in  producing  or  acting  as  effective  stimuli  for 
adaptive  variations  of  the  usual  course  of  life.  Slingerland  reared  ninety- 
four  successive  generations  (in 
four  years)  of  an  aphid  species 
in  the  insectary  at  Cornell 
University  under  such  constant 
conditions  of  food-supply  and 
summer  temperature  that  not 
a  single  winged  aphid  nor  single 
sexual  generation  was  pro- 
duced. Even  longer  series  of 
identical  wingless  agamic  gen- 
erations have  been  obtained  by 
certain  European  experiment- 
ers. Clarke,  in  California,  has 
been  able  to  produce  a  winged 
generation  at  will  by  simply 
changing  the  chemical  constitu- 
tion of  the  sap  of  the  host- 
plant  on  which  the  aphids  were 
reared  in  his  laboratory. 

In  addition  to  the  interest- 
ing variation  as  regards  wings 
and  reproductive  processes 
among  the  various  individuals 
of  a  single  aphid  species,  it  has  been  found  that  of  the  wingless  males  some 
have  no  mouth,  while  others  are  furnished  with  functional  mouth-parts 
and  opening.  An  interesting  physiological  variation  also  occurs  in  the 
matter  of  the  food-plant  selected.  The  winged  individuals  frequently 
migrate  to  a  plant  of  different  species  from  that  on  which  they  were  born. 
For  instance,  the  apple-aphids.  Aphis  mali,  "spend  the  summer  upon  grasses, 
where  they  continue  breeding  until  autumn,  when  they  return  to  the  apple  and 
the  winged  females  establish  colonies  of  the  wingless  egg-laying  form  upon 
the  leaves.  The  males  fly  in  from  the  summer  host-plant;  the  eggs  are 
then  laid  on  the  twigs  and  buds,  and  the  cycle  for  the  year  is  completed." 
The  common  cherry-aphis,  Myzus  cerasi,  has  a  similar  history,  described  by 


Fig.  247. — Rose-aphids  visited  by  ants, 
size;  from  life.) 


(Natural 


Bugs,  Cicadas,  Aphids,  and  Scale-insects         175 

Weed  as  follows:  "It  winters  over  on  the  twigs  in  the  egg  state.  Early 
in  spring  the  young  aphids  hatch  and  crawl  upon  the  bursting  buds,  insert- 
ing their  tiny  sap-sucking  beaks  into  the  tissues ~of  the  unfolding  leaves. 
In  a  week  or  ten  days  they  become  full-grown  and  begin  giving  birth  to 
young  lice,  that  also  soon  develop  and  repeat  the  process,  increasing  very 
rapidly.  Most  of  the  early  spring  forms  are  wingless,  but  during  June 
great  numbers  of  the  winged  lice  appear,  and  late  in  June  or  early  in  July 
they  generally  leave  the  cherry,  migrating  to  some  other  plant,  although 
we  do  not  yet  know  what  that  plant  is.  Here  they  continue  developing 
throughout  the  summer,  and  in  autumn  a  winged  brood  again  appears  and 
migrates  back  to  cherry.  These  migrants  give  birth  to  young  that  develop 
into  egg-laying  females  which  deposit  small,  oval,  shining  black  eggs  upon 
the  twigs." 

The  point  of  all  this  is  plainly  that  in  the  aphids  there  must  be  recog- 
nized an  unusual  and,  to  them,  very  advantageous  adaptive  plasticity  of  both 
structure  and  function.  Defenceless  as  are  the  aphid  individuals  as  far 
as  capacity  either  to  fight  or  to  run  away  is  concerned,  the  various  aphid 
species  are,  on  the  contrary,  very  well  defended  by  their  structural  and  physi- 
ological plasticity  and  their  extraordinary  fecundity. 

The  two  secretions,  wax  and  honey-dew,  play  an  important  part  in  the 
aphid  life.  The  wax  secreted  or  excreted  through  various  small  openings 
scattered  over  the  body  is,  of  course,  liquid  when  first  produced,  but  quickly 
hardens;  the  total  waxy  secretion  appears  usually  as  a  mass  of  felted  threads 
or  "wool,"  and  doubtless  is  an  important  protection  for  the  deUcate  body. 
The  honey-dew,  long  supposed  to  be  secreted  through  two  conspicuous 
tubular  processes  on  the  dorsal  surface  of  the  posterior  end  of  the  abdomen, 
is  now  known  to  be  an  excretion  from  the  intestine,  issuing  in  fine  droplets 
or  even  spray  from  the  anal  opening.  From  the  so-called  "honey-tubes" 
issues  another  secretion,  not  sweetish,  about  which  Httle  is  known.  It  is 
common  knowledge,  however,  that  the  aphid  honey-dew  is  a  favorite  food 
of  ants— the  Germans  call  it  the  ants'  "national  dish"— and  many  accounts 
have  been  written  of  the  care  of  plant-lice,  the  ants'  cattle,  by  the  ants  them- 
selves. Without  question  there  is  some  basis  of  fact  for  these  stories.  No 
more  evidence  of  this  is  needed  than  the  careful  observations  of  Professor 
Forbes  of  the  extraordinary  care  of  the  corn-root  louse  by  the  little  brown 
ant,  Lasius  brnnneus,  of  the  Mississippi  Valley  corn-fields  (see  p.  545  for  an 
account  of  this).  The  feeding  by  ants  on  the  fresh  honey-dew  can  be  readily 
observed  in  almost  any  garden  (Fig.  247),  and  undoubtedly  the  mere  presence 
in  the  aphid  neighborhood  of  such  redoubtable  warriors  as  the  ants  is  a 
strong  deterrent  of  various  predaceous  insect  enemies  of  the  plant-lice. 
But  most  of  the  stories  of  ants  and  aphids  printed  in  popular  natural-history 
books  need  to  be  tested  by  careful  observation. 


176        Bugs,  Cicadas,   Aphids,  and  Scale-insects 

Of  all  aphid  species  the  grape-phylloxera,  Phylloxera  vastatrix  (Fig.  248), 
has  deservedly  the  widest  notoriety.  First  made  known  in  1853  by  Fitch  from 
specimens  found  in  New  York,  it  was  soon  discovered  to  be  well  scattered  on 
wild  vines  over  the  eastern  United  States.  "It  was  introduced  into  the 
south  of  France  before  1863,  upon  rooted  vines  sent  from  America; 
though  the  insect  itself  was  not  found  and  described  there  until  1868. 
The  infection  commenced  at  two  points:  one  in  the  southeast  in  Card, 
the  other  in  the  southwest  near  Bordeaux.  In  1868,  when  the  nature  of 
the  pest  was  understood,  it  had  already  invaded  considerable  areas.     The 


Fig.  248. — The  grape-phylloxera.  In  upper  left-hand  corner  an  egg  from  which  a  male 
has  issued,  next  an  egg  from  which  a  female  has  issued;  in  upper  right-hand  corner 
winter  egg;  at  left  hand  of  middle  row  a  just-hatched  young,  next  a  male  (note 
absence  of  mouth-parts);  at  right  end  of  middle  row,  female;  lower  figure,  winged 
form.     (After  Ritter  and  Riibsaamen;    much  enlarged.) 

two  areas  first  attacked  gradually  enlarged  until  they  touched  about  the 
year  1880,  and  the  insect  began  to  spread  northward.  By  1884  about 
2,500,000  acres,  more  than  one-third  of  all  the  vineyards  of  France,  had 
been  destroyed  and  nearly  all  the  rest  were  more  or  less  affected.  The 
progress  of  the  disease  in  parts  of  southern  France  was  so  rapid  that  in  some 
towns  vine-stumps  became  the  principal  fuel.  Since  1884  the  pest  has 
continued  to  spread  with  somewhat  less  rapidity  in  France,  partly  because 
the  most  densely  planted  vineyard  districts  had  already  been  devastated, 
but  also  because  elsewhere  its  progress  was  retarded  by  quarantine  and 
other  restrictive  measures.  No  remedies  yet  discovered,  however,  are 
capable    of    exterminating    the  pest;    and   to-day  there    is    no  vine-grow- 


Bugs,  Cicadas,  Aphids,  and  Scale-insects         177 

ing     region    of    any    importance    in    France,    or    elsewhere,    exempt    from 
phylloxera." 

Curiously  enough  this  native  American  pest  came  to  California,  in  which 
state  it  has  done  much  more  damage  than  elsewhere  in  our  country,  from 
France,  introduced  on  imported  cuttings  or  roots.  It  was  tirst  noticed  about 
1874;  by  1880  vines  had  been  killed  by  phylloxera  in  three  counties  and 
hundreds  of  acres  had  been  pulled  up  in  the  famous  Sonoma  Valley. 
Since  then  the  pest  has  spread,  according  to  Bioletti,  to  all  the  important 
grape-growing  regions  of  central  and  northern  California,  and  probably  not 
less  than  30,000  acres  of  vineyards  have  been  destroyed. 

The  phylloxera  appears  normally  in  four  forms:  (i)  the  gall  form,  living 
in  little  galls  on  the  leaves,  and  capable  of  very  rapid  multiplication  (this 
form  rarely  appears  in  California);  (2)  the  root  form,  which  is  derived  from 
individuals  which  migrate  from  the  leaves  to  the  roots,  and  which,  by  its 
piercing  of  the  roots,  sucking  the  sap,  and  producing  little  quickly  de- 
caying tubercles  on  the  rootlets,  does  the  serious  injury;  (3)  the  winged 
form,  which  flies  to  new  vines  and  vineyards  and  starts  new  colonies;  and 
finally  (4)  the  sexual  forms,  male  and  female,  which  are  the  regenerat- 
ing individuals,  appearing  after  several  agamic  generations  have  been 
produced. 

The  life-history  of  the  pest  has  been  described  as  follows  by  Bioletti: 
"Some  time  during  the  summer,  usually  in  July  or  August,  some  of  the  eggs 
laid  by  the  root-insects  develop  into  insects  of  slightly  different  form,  called 
nymphs.  They  are  somewhat  larger  than  the  normal  root  form  and  show 
slight  protuberances  on  the  sides,  which  finally  develop  into  wings.  These 
are  the  winged  or  colonizing  insects,  which  emerge  from  the  soil  and,  though 
possessing  very  weak  powers  of  flight,  are  capable  of  sailing  a  short  distance, 
and  if  a  wind  is  blowing  may  be  taken  many  rods  or  even  miles.  Those 
which  reach  a  vine  crawl  to  the  under  side  of  a  leaf  and  deposit  from  three 
to  six  eggs.  These  eggs  are  of  two  sizes,  the  smaller  of  which  produce  males 
and  the  larger  females.  The  female,  after  fertilization,  migrates  to  the 
rough  bark  of  the  two-year-old  wood,  where  she  deposits  a  single  egg,  called 
the  winter  egg,  which  remains  upon  the  vine  until  the  following  spring. 
The  insect  which  hatches  from  this  egg  in  the  spring  goes  either  to  the  young 
leaves  and  becomes  a  gall-maker,  or  descends  to  the  roots  and  gives  rise  to 
a  new  generation  of  egg-laying  root-feeders.  The  normal  and  complete 
life-cycle  of  the  phylloxera  appears  then  to  be  as  follows:  Male  and  female 
insects  (one  generation  in  autumn);  gall-insects  (one  to  five  generations 
while  the  vines  are  in  leaf);  root-insects  (an  unknown  number  of  genera- 
tions throughout  the  year);  nymphs,  which  become  winged  insects  (one 
generation  in  midsummer).  The  gall  stage  may  be  omitted,  as  it  generally 
is  in  California,  and  the  insects  which  hatch  from  the  fertilized  eggs  laid  by 


1 78         Bugs,  Cicadas,  Aphids,  and  Scale-insects 

the  female  go  directly  to  the  root  and  produce  offspring  which  are  in- 
distinguishable from  the  root  form  produced  in  the  normal  cycle.  For 
how  many  generations  the  root  form  can  exist  and  reproduce  without  the 
invigoration  supposed  to  come  from  the  production  of  the  sexual  form  is 
not   known,   but   certainly  for  four  years  and  probably   for  more.      The 


Fig.  249. — Roots  and  rootlets  of  grape-vine  infested  by  the  phylloxera.     (After  Ritter 
and  Riibsaamen;    enlarged.) 

gall  form  on  American  vines  can  be  prevented  by  spraying  the  vines  in 
winter  with  liquids  to  kill  the  winter  eggs;  but  this  treatment  has  no 
effect  on  the  root  forms,  which  in  California  hibernate  abundantly  in  the 
soil." 

All  forms  of  the  phylloxera  species  are  very  small,  about  -j'-g-  of  an  inch 
being  an  average  for  fully  developed  individuals.  The  root  form  is  light 
greenish  yellow  in  summer,  when  it  can  be  found  by  examining  the  rootlets 
of  infested  vines,  and  bronzy  purplish  in  winter,  when  it  can  be  found  in 
little  patches  under  the  bark  just  at  the  crown  of  the  vine.     The  newly 


Bugs,  Cicadas,  Aphids,  and  Scale-insects         179 

hatched  young  of  the  root  form  moves  about  freely,  but  when  it  reaches 
the  egg-laying  stage  it  becomes  fixed. 

The  chief  injury  to  the  vine  is  not  sap-drinking,  but  the  decaying  or 
"cancer"  of  the  roots  caused  by  the  punctures  and  tubercle  forming  (Fig. 
249).  It  usually  takes  tw^o  or  three  years  for  phylloxera  to  kill  a  vine,  but 
the  results  of  the  infestation  are  shown  each  season  in  the  increasingly  reduced 
growth  of  the  new  wood  and  in  the  lessened  bearing.  Suspected  vines 
should  be  dug  up  and  the  rootlets  carefully  examined  for  tubercles  and 
the  insects  themselves.  The  remedies,  unfortunately,  are  either  expensive, 
difficult,  or  severe.  If  a  vineyard  can  be  submerged  for  six  weeks  under 
at  least  six  inches  of  water,  the  insects  will  be  killed  (by  suffocation).  Car- 
bon disulphide  can  be  put  into  the  soil  among  the  roots  by  an  injector  at 
a  cost  of  from  ten  to  twenty  dollars  an  acre.  "  This  method  succeeds  only 
in  rich,  deep,  loose  soils  and  cannot  be  successfully  used  in  soil  containing 
much  clay  or  on  dry  rocky  hillsides."  Finally,  most  severe  but  most  effec- 
tive is  the  digging  up  of  the  whole  of  an  infested  vineyard  and  replanting 
resistant  vines.  "A  resistant  vine  is  one  which  is  capable  of  keeping  alive 
and  growing  even  when  phylloxera  are  living  upon  its  roots.  Its  resistance 
depends  on  two  facts:  first,  that  the  insects  do  not  increase  so  rapidly  on 
its  roots;  and  second,  that  the  swellings  of  diseased  tissue  caused  by  the 
punctures  of  the  insects  do  not  extend  deeper  than  the  bark  of  the  rootlets 
and  are  sloughed  off  every  year,  leaving  the  roots  as  healthy  as  before. 
The  wild  vines  of  the  Mississippi  States  have  evolved  in  company  with  the 
phylloxera,  and  it  is  naturally  among  these  that  we  find  the  most  resistant 
forms.  No  vine  is  thoroughly  resistant  in  the  sense  that  phylloxera  will  not 
attack  it  at  all;  but  on  the  most  resistant  the  damage  is  so  sHght  as  to  be 
imperceptible.  The  European  vine,  Vitis  vinifera  L.,  is  the  most  suscep- 
tible of  all,  and  all  the  grapes  cultivated  in  California,  with  a  few  unimportant 
exceptions,  belong  to  this  species."  But  the  preferred  French  stocks  can 
be  grafted  on  to  resistant  American  roots  and  the  vineyard  made  practically 
immune.  This  is  the  method  which  has  rehabilitated  the  French  vine- 
yards and  is  now  rehabilitating  the  -California  ones. 

Another  very  important  aphid  pest  of  this  country  is  the  woolly 
apple-aphis,  called  in  England  and  in  Europe  the  American  blight.  This 
species,  like  the  phylloxera,  appears  in  different  forms  and  lives  both  above 
ground  on  the  twigs  and  larger  branches  and  underground  on  the  roots. 
It  makes  itself  conspicuous  and  readily  recognizable  by  the  abundant  fluffy 
waxen  "wool"  which  it  secretes.  Badly  attacked  trees  have  the  bark  of 
their  branches  badly  "cankered"  and  the  roots  covered  with  excrescences, 
and  may  die.  The  injuries  are  almost  always  severe,  and  the  pest  is  one 
difficult  to  eradicate.  If  but  few  trees  in  an  orchard  are  attacked,  it  is  best 
to  dig  them  up  and  burn  them.     The  bark  can  be  thoroughly  sprayed  or 


I  80         Bugs,  Cicadas,  Aphids,  and  Scale-insects 

scrubbed  with  a  carbolized  solution  of  soft  soap  (soap  10  parts,  carbolic 
acid  2  parts,  water  88  parts)  and  carbon  disulphide  injected  into  the  soil  about 
the  base  of  the  tree. 

Of  the  various  aphids  which  attack  foliage  trees,  the  most  familiar  are 
those  which  resemble  the  woolly  apple-aphis  in  their  habit  of  secreting  floc- 
culent  masses  of  wax,  and  thus  obtain  the  name  of  "  blight,"  as  elm-blight, 
beech-blight,  alder-blight,  etc.  The  alder-blight,  or  woolly  alder-aphis. 
Pemphigus  tessellata,  gives  birth  in  autumn  to  vast  numbers  which  crawl 
down  the  trunks  to  the  ground,  where  they  congregate  in  the  crevices  between 
the  base  of  the  trunk  and  larger  roots  and  the  soil,  or  beneath  the  fallen  leaves 
or  other  rubbish  at  the  surface.  They  remain  in  their  hiding-place  until 
spring,  when  at  the  coming  of  the  first  warm  days  they  crawl  up  the  tree 
and  out  to  the  budding  tips  of  the  twigs.  Here  they  begin  sucking  sap  and 
at  the  same  time  secreting  waxen  "wool."  In  a  week  or  so  they  become 
mature  and  begin  giving  birth  to  living  young,  and  hereafter  during  the 
autumn  and  summer  agamic  generation  after  generation  is  produced.  With 
the  oncoming  of  cold  weather  the  last  generation  crawls  down  to  the  ground 
to  seek  winter  quarters.  No  sexual  forms  of  this  species  have  yet  been 
found. 

Among  the  gall-forming  aphids,  one  of  special  interest,  because  of  the 
strange  character  and  abundance  of  its  galls,  is  the  cockscomb  gall-louse, 
Colopha  ulmicola.  Elm-trees  infested  by  this  aphis  develop  on  the  upper 
side  of  the  leaves  narrow,  erect,  blackish  galls  irregularly  toothed  along 
the  top,  and  suggesting  a  cock's  comb  sufficiently  to  warrant  the  common 
name.  These  aphids  secrete  much  honey-dew,  noticeable  on  sidewalks 
under  the  trees  and  on  the  leaves,  and  in  this  honey-dew  where  it  covers 
the  galls  and  leaves  grows  a  blackish  fungus. 

Of  all  the  families  of  the  Hemiptera,  probably  the  most  important  from 
the  economic  entomologist's  point  of  view  is  that  of  the  Coccidae,  or  scale- 
insects,  and  from  the  point  of  view  of  the  biological  student,  also,  no  other 
is  more  interesting  and  suggestive.  More  nearly  on  a  footing  with  the 
Coccids  than  any  other  Hemiptera  are  the  Aphididas,  just  studied,  but  the 
scale-insects  are  even  more  specialized  in  curious  and  unusual  ways,  both 
as  regards  structure  and  physiology.  In  the  more  specialized  scale-insects 
the  females  are  quiescent  in  adult  life,  as  well  as  in  part  of  the  immature 
life,  and  their  fixed  bodies  are  very  degenerate,  lacking  both  organs  of  loco- 
motion and  of  orientation,  viz.,  eyes,  antennae,  wings,  and  legs.  The  family 
is  a  large  and  widely  distributed  one,  numbering  about  1450  known  species 
in  the  world,  of  which  385  occur  in  the  United  States,  but  almost  all  are 
small  and  obscure  and  so  foreign  in  appearance  to  the  usual  insect  type 
that  but  few  others  than  professional  entomologists  and  the  harassed  fruit- 
growers ever  recognize  them  as  insects.     Most  of  us  have  often  had  oppor- 


Bugs,  Cicadas,  Aphids,  and  Scale-insects  18  i 

tunily  to  make  easy  acquaintance  with  one  or  two  species  at  our  breakfast- 
tables;  the  t^attish,  nearly  circular  little  red-brown  spots,  or  the  more 
ovate  blackish  spots,  which  are  occasionally  to  be  seen  on  carelessly  packed 
oranges  are  scale-insects  and  excellent  examples  of  the  extremie  of  degen- 
erate, quiescent  type.  The  adult  male  scale-insects,  unlike  the  females, 
are  winged  (although  possessing  but  a  single  pair)  and  have  eyes,  an- 
tennae, and  legs,  but,  strangely  enough,  no  mouth-parts  nor  mouth-opening, 
so  that  they  can  take  no  food  and  must  necessarily  have  but  a  few  hours  or 
perhaps  days,  at  most,  of  life.  And  they  are  much  more  rarely  seen 
than  the  females.  Indeed,  of  many  scale-insect  species  the  males  are  not 
yet  known,  it  being  possible  that  in  some  species  there  is  no  male  sex  at 
all. 

The  economic  importance  of  the  scale-insects  has  been  keenly  appre- 
ciated on  the  Pacific  Coast  ever  since  fruit-growing  came  to  be  a  leading 
industry  there,  but  the  rest  of  the  United  States  had  not  had  to  worry  itself 
much  because  of  the  existence  of  these  insect-scourges  until  recent  years. 
A  single  Coccid  species,  however,  has 
within  ten  years  called  the  attention 
of  entomologists  and  orchardmen 
and  legislators  all  over  the  country  to 
itself  in  a  very  illuminating  manner. 
This  species,  the  ill-named  San  Jose 
scale,  Aspidiohis  perniciosus, — which 
should  rather  be  called  "the  perni- 
cious scale,"  or,  if  not  that,  then  the 

Oriental  scale,  as  it  is  a  native  of  Japan 

^,  .  r     .  J      1  .        Fig.  2t;o. — San  Tose  scale  on  bark  of  fruit- 

or  China,— was   first  made    known   to        ^^^^/  (After  Slingerland;  natural  size.) 

science,  and  named,  by  Prof .  J.  H.  Com- 

stock  in  1880.  Professor  Comstock's  specimens  were  collected  in  the  Santa 
Clara  Valley  near  San  Jose,  California.  How  much  earlier  the  species 
had  been  brought  to  California  is  not  known,  but  at  the  time  of  its  naming 
by  Professor  Comstock  it  was  already  recognized  by  California  fruit-growers 
as  a  serious  pest,  and  Comstock  wrote:  "From  what  I  have  seen  of  it  I  think 
it  is  the  most  pernicious  scale-insect  known  in  this  country."  In  August, 
1893,  it  was  found  to  have  got  a  footing  in  the  east,  and  since  then  no  other 
injurious  insect — indeed  hardly  all  others  together — has  received  such  con- 
stant and  excited  attention  as  has  this  obscure  little  pest.  It  is  found  now 
in  every  state  and  territory  of  the  Union,  and  in  Canada  as  well,  and  in 
thirty-five  states  has  been  the  subject  of  hurried — and  only  partly  w'ell- 
advised — legislation.  This  legislation  has  been  directed  toward  restricting 
its  spread  by  (a)  quarantining  it  at  the  states'  borders,  and  {h)  inspecting 
orchards  and  nurseries  for  it  within  the  state  and  attempting  to  stamp  it 


I  82         Bugs,  Cicadas,  Aphids,  and  Scale-insects 


out.     The  structural  characteristics  and  life-history  of  the  insect  may  be 
briefly  described  as  follows: 

There  may  be  seen  on  infested  branches,  leaves,  or  fruit,  small,  flat, 
grayish,  irregularly  circular  scales  of  varying  size  (Figs.  250  and  251),  the 
large  stones  (about  -^j  inch  diameter)  being  the  adult  females  and  the  smaller 

ones  being  the  immature  individuals 
of  both  sexes.  These  circles  are  thin 
waxen  plates,  bearing  one  or  more  (de- 
pending on  the  age  of  the  individual) 
faintly  yellowish  concentric  inner  cir- 
cles or  plates  (the  inner  one  usually 
blackish  and  like  a  tiny  nipple)  which 
are  the  moulted  exuviae  of  the  scale. 
When  the  plant  is  badly  infested  the 
scales  lie  thickly  together,  even  overlap- 
ping, and  forming  a  sort  of  grayish 
scurf  over  the  smooth  bark.  By  rubbing 
or  crushing  this  scurf  a  yellowish  oily 
liquid  issues  from  the  injured  bodies. 
If  a  scale  be  tipped  over  with  a  pin- 
point, there  will  be  found  underneath 
it  a  delicate  flattened  yellowish  sac-like 
creature,  the  insect  itself  (Fig.  252). 
If  adult,  this  degenerate  female  will  be 
seen  (by  examination  with  magnifier) 
to  have  no  distinct  head,  no  eyes  nor 
antennae,  no  wings  nor  legs.  It  does  have  a  long,  fine,  flexible,  thread-like 
process  projecting  from  near  the  center  of  its  under  side;  this  is  the  suck- 
ing proboscis,  and  serves  as  a  means  of  attachment  to  the  plant  as  well 
as  the  organ  of  feeding. 

Early  in  the  spring,  females  which  have  hibernated  under  their  pro- 
tecting armor  begin  giving  birth  to  living  young,  and  continue  doing  this 
actively  for  about  six  weeks,  when  they  die  exhausted.  The  minute  orange- 
yellow  young,  which  have  eyes,  antennae,  and  three  pairs  of  legs,  crawl  out 
from  under  the  scale  and  run  about  actively  for  a  few  hours  over  the  twigs 
or  leaves;  then  they  settle  down  and  each*  "slowly  works  its  long  bristle- 
like sucking-beak  through  the  bark,  folds  its  antennae  and  legs  beneath  its 
body  and  contracts  to  a  nearly  circular  form.  The  development  of  the 
scale   begins   even   before   the  larva  becomes   fixed.     The   secretion   starts 


Fig.  251. — The  San  Jose  scale,  Aspi- 
diolus  perniciosus,  females  and  young, 
on  bark  of  fruit-tree.  (From  living 
specimens;  at  left,  natural  size;  at 
right,  considerably  enlarged.) 


*  The  following  long  quotation  is  made  from  Howard  and  Marlatt's  "  The  San  Jose 
Scale  "  (Bull.  3,  N.  S.,  Div.  Ent.,  U.  S.  Dept.  Agric,   1896). 


Bugs,  cicadas,  Aphids,  and  Scale-insects         183 

in  the  form  of  very  minute  white  fibrous  waxy  filaments,  which  spring  from 
all  parts  of  the  body  and  rapidly  become  more  numerous  and  dense.  At 
first  the  orange  color  of  the  larva  shows  through  the  thickening  downy  white 
envelope,  but  within  two  days  the  insect  becomes  entirely  concealed  by  the 
white  or  pale  grayish-yellow  shell  or  scale,  which  now  has  a  prominent  central 
nipple,  the  younger  ones  often  possessing  instead  a  central  tuft.  The  scale 
is  formed  by  the  slow  matting  and  melting  together  of  the  filaments  of  wax. 
During  the  first  day  the  scale  appears  like  a  very  microscopic  downy  hemi- 
sphere. The  matting  of  the  secretion  continues  until  the  appearance  of 
down  and  individual  filaments  is  entirely  lost  and  the  surface  becomes 
smooth.  In  the  early  history  of  the  scale  it  maintains  its  pale  whitish  or 
grayish-yellow  color,  turning  gradually  darker  gray,  the  central  nipple 
remaining  lighter  colored,  usually  throughout  development. 

"The  male  and  female  scales  are  exactly  similar  in  size,  color,  and  shape 
until  after  the  first  moult,  which  occurs  twelve  days  after  the  emergence  of 
the  larva.  With  this  moult,  however,  the  insects  beneath  the  scale  lose  all 
resemblance  to  each  other.  The  males  (Fig.  252,  a)  are  rather  larger  than 
the  females,  and  have  large  purple  eyes,  while  the  females  have  lost  their 
eyes  entirely.  The  legs  and  antennje  have  disappeared  in  both  sexes.  The 
males  are  elongate  and  pyriform,  while  the  females  are  almost  circular, 
amounting  practically  to  a  flattened  sac  with  indistinct  segmentation, 
and  without  organs,  except  a  long  sucking-bristle  springing  from  near  the 
center  beneath.  The  color  of  both  sexes  is  light  lemon-yellow.  The 
scales  at  this  time  have  a  decidedly  grayish  tint,  overcast  somewhat  with 
yellow. 

"Eighteen  days  from  birth  the  males  change  to  the  first  pupal  condition 
(propupa),  and  the  male  scales  assume  an  elongate  oval,  sometimes  shghtly 
curved  shape,  characteristic  of  the  sex,  the  exuvia  or  cast  larval  skin  show- 
ing near  the  anterior  end.  The  male  propupas  are  very  pale  yellow,  with 
the  legs  and  antennae  (which  have  reappeared)  together  with  the  two  or  three 
terminal  segments  colorless.  .  .  .  Prominent  wing-pads  extend  along  the  side 
of  the  body. 

"The  female  undergoes  a  second  moult  about  twenty  days  from  the 
larva.  At  each  moult  the  old  skin  spHts  around  the  edge  of  the  body,  the 
upper  half  adhering  to  the  covering  scale  and  the  lower  forming  a  sort  of 
ventral  scale  next  to  the  bark.  This  form  of  moulting  is  common  to  scales 
of  this  kind. 

"The  covering  scales  at  this  stage  are  of  a  more  purplish  gray,  the  por- 
tion covering  the  exuviae  inclining  to  yellowish.  The  male  scales  are  more 
yellowish  than  the  female.  The  effect  of  the  sucking  of  the  insects  is  now 
quite  apparent  on  the  young  growth,  causing  the  bark  to  assume  a  pur- 
plish hue  for  some  distance  around  the  central  portion,  contrasting  strongly 


184         Bugs,  Cicadas,  Aphids,  and  Scale-insects 


Fig.  252. — The  San 
Jose  scale,  Aspidiotiis 
perniciosus.  a,  male; 
/),  a  d  u  1 1  female. 
(Much  enlarged.) 


with  the  natural  reddish  green  of  the  uninjured  bark.  With  the  second 
moult  the  females  do  not  change  materially  from 
their  former  appearance,  retaining  the  pale-yellow 
color  with  a  number  of  transparent  spots  around 
the  edge  of  the  body.  The  sucking-bristles  are 
extremely  long,  two  or  three  times  the  length  of  the 
body  of  the    insect. 

"About  twenty  days  after  birth  the  male  insect 
transforms  to  the  true  pupa.  With  the  first  moult 
the  shed  larval  skin  is  retained  beneath  the  scale 
as  in  the  case  of  the  female;  with  the  later  moult- 
ings  the  shed  skins  are  pushed  out  from  beneath 
the  scale.  The  scale,  after  the  second  moult,  pre- 
sents on  the  inside  two  longitudinal  ridges  run- 
ning from  one  end  to  the  other,  touching  the  sides 
of  the  pupa,  and  which  apparently  enable  the 
insect  to  move  backward  or  forward  and  assist  the  imago  in  pushing  itself 
out. 

"The  true  pupa  is  pale  yellow,  sometimes  purplish,  darkened  about 
the  base  of  the  abdomen.  The  head,  antennae,  legs,  wing-pads,  and  style 
are  well  formed,  but  almost  colorless.  .  .  . 

"From  four  to  six  days  later,  or  from  twenty-four  to  twenty-six  days 
from  birth,  the  males  mature  and  back  out  from  the  rear  end  of  their 
scales,  having  previously,  for  a  day  or  two,  remained  practically  developed, 
but  resting  under  the  scale.  They  seem  to  issue  chiefly  by  night  or  in 
the  evening. 

"The  mature  male  (Fig.  252)  appears  as  a  delicate  two-winged  fly-like 
insect  with  long  feelers  and  a  single  anal  style  projecting  from  the  end  of 
the  body;  orange  in  color,  with  a  faintly  dusky  shade  on  the  prothorax. 
The  head  is  darker  than  the  rest  of  the  body,  the  eyes  are  dark  purple,  and 
the  antennae,  legs,  and  style  are  smoky.  The  wings  are  iridescent  with 
yellow  and  green,  very  faintly  clouded. 

"Thirty  days  from  birth  the  females  are  full  grown  and  the  embryonic 
young  may  be  seen  within  their  bodies,  each  enclosed  in  a  delicate  mem- 
brane. At  from  thirty-three  to  forty  days  the  larvae  again  begin  to  make 
their  appearance. 

"The  adult  female,  prior  to  the  development  of  the  young,  measures 
one  millimeter  in  length  and  a  little  less  in  breadth,  and  is  pale  yellow  with 
transparent  spots  near  the  margin  of  the  body  (Fig.  252). 

"The  length  of  a  generation  is  determined  by  the  female,  and,  as  shown 
by  the  above  record,  covers  a  period  of  from  thirty-three  to  forty  days.  Suc- 
cessive  generations   were   followed   carefully   throughout   the   summer,   and 


Bugs,  Cicadas,  Aphids,  and  Scale-insects  185 

it  was  found  that  at  Washington  four  fuU  generations  are  reguhirly  developed, 
with  the  possibiUty  of  a  partial  fifth  generation.  On  a  number  of  potted 
trees  a  single  overwintered  female  was  left  to  each  tree.  After  the  full 
progeny  of  this  individual  had  gone  out  over  the  tree  all  were  removed 
again,  except  one  of  the  oldest  and  fertilized  females.  This  method  was 
continued  for  each  generation  throughout  the  breeding  season.  Some 
interesting  records  .  .  .  were  thus  obtained,  which  indicate  the  fecundity 
of  the  females  as  well  as  the  number  of  generations." 

From  these  records  it  may  be  fairly  estimated  that  an  average  of  200 
females  (in  addition  to  about  as  many  males)  are  produced  by  each  female, 
and  that  there  are  four  generations  each  year  in  the  latitude  of  Washington, 
D.  C.  Thus  the  product  of  a  single  overwintered  female  in  a  single  year 
amounts  to  3,216,080,400  male  and  female  descendants.  This  total  is, 
of  course,  never  reached,  because  only  a  part  of  each  generation  reaches 
maturity  and  produces  young,  but  in  a  favorable  season  on  a  tree  newly 
infested  (and  thus  providing  a  plentiful  food-supply)  a  large  majority  of 
each  generation  do  most  probably  go  through  their  normal  existence. 
"Neither  the  rapidity  with  which  trees  become  infested,"  add  Howard  and 
Marlatt,  "nor  the  fatal  effect  which  so  early  follows  the  appearance  of  this 
scale-insect  is  therefore  to  be  wondered  at." 

But  not  all  scale-insects  are  so  specialized  either  structurally  or  physio- 
logically as  the  pernicious  (or  San  Jose)  scale.  The  females  of  some  species 
retain  the  eyes,  antennae,  and  legs  through  their  whole  life  and  can  crawl 
about  if  need  be  at  any  time.  Others  show  a  sort  of  transition  between 
these  two  extremes  of  activity  and  quiescence,  having  the  legs  present,  but 
in  adult  life  much  reduced  in  size  and  probably  functionless,  or  at  best 
capable  of  carrying  the  insect  but  feebly  and  briefly.  In  the  matter  of  the 
covering,  too,  there  is  much  variety;  some  scales  secrete  no  wax  at  all,  but 
have  the  body-wall  of  the  back  specially  thickened  and  made  firm  so  as 
to  act  as  an  effective  covering-shield  underneath  which,  somewhat  as  with 
a  turtle,  the  legs  and  head  can  be  concealed.  Others  secrete  filaments  or 
tufts  of  soft  white  wax  which  form  a  sort  of  felted  protecting  covering  for  the 
body.  In  a  general  way  the  various  scale-insects  may  be  instructively 
gathered  into  three  groups,  depending  on  the  characters  of  the  females; 
in  the  first  group  the  females  retain  the  antennae,  eyes,  and  legs,  and  the 
segmented  condition  of  the  body  (typical  of  normal  insects)  and  are  capable 
of  locomotion  throughout  life;  they  secrete  wax  usually  in  the  shape  of  white 
cottony  filaments  or  masses  with  which  they  cover  the  body  more  or  less 
completely,  sometimes  forming  conspicuous  waxen  egg-sacs  at  the  posterior 
extremity  of  the  body;  the  females  of  the  second  group  retain  their  legs 
and  antennae  through  life,  but  have  them  in  reduced  condition  when  adult, 
and  although  capable  of  feeble  motion,  usually  lie  quiescent;  they  commonly 


1 86         Bugs,  Cicadas,  Aphids,  and  Scale-insects 


Fig.  253. — The  fluted  or  cottony 
cushion-scale,  Icerya  purchasi, 
winged  male  and  wingless 
female  with  fluted  waxen  egg- 
sac  {es).  (After  Jordan  and 
Kellogg,  much  enlarged.) 


secrete  no  wax,  but  have  the  body-wall  of  the  dorsum  strongly  chitinized, 

and  usually  very  convex,  so  that  it  forms 
a  strong  rigid  protecting  shell;  finally  the 
females  of  the  third  (and  largest)  group  are 
the  so-called  armored  scales,  which  in  the 
adult  stage  are  degenerate  creatures  without 
distinct  body  segmentation,  without  antennae, 
eyes,  and  legs,  thus  being  incapable  of 
locomotion;  they  form  a  flatfish  or  convex 
dorsal  scale  of  secreted  wax  and  of  the  cast 
skins  or  exuviae  of  the  body. 

In  all  the  groups  the  males  (Figs.  252  and 
253)  are  very  different  in  appearance  from  the 
females,  being  minute  fly-like  creatures  with 
a  single  pair  of  wings,  a  pair  of  long  antennae, 
and  a  plump,  soft,  little  body,  usually 
terminating  in  a  single  needle-like  process  or 
in  a  pair  of  long  waxen  hairs.  Males  are 
not  yet  known  for  some  of  the  species. 
Familiar  examples  of  the  first  group  are  the  mealy-bugs  {Dadylopiits  sp.) 
of  greenhouses  and  gardens,  soft-bodied  scales,  bearing  projecting  rods 
and  threads  of  white  wax  of  varying  length,  and  rather  prettily  arranged. 
A  more  famous  and  interesting  member  of  this  group  is  the  fluted  or  cottony 
cushion-scale,  Icerya  purchasi  (Fig.  253)  (so  called  because  of  the  beautiful 
fluted  white  waxen  egg-sac  secreted  by  the  female),  which  once  threatened 
to  destroy  all  the  orange-groves  of  California,  but  was  brought  to  bay  by 
a  little  red  and  black  ladybird-beetle,  Vedalia  cardinaJis  (Fig.  254),  brought 
from  Australia  for  this  very  purpose.  In  1868  some  young  orange-trees 
were  brought  to  Menlo  Park  (near  San  Francisco)  from  Australia.  These 
trees  were  undoubtedly  infested  by  the  fluted  scale,  which  is  a  native  of 
Australia.  These  scale  immigrants  throve  in  the  balmy  California  climate, 
and  particularly  well,  probably,  because  they  had  left  all  their  native  enemies 
far  behind.  By  1880  they  had  spread  to  the  great  orange-growing  districts  of 
southern  California,  five  hundred  miles  away,  and  in  the  next  ten  years 
caused  enormous  loss  to  the  growers.  In  1888  the  entomologist  Kcebele, 
recommended  by  the  government  division  of  entomology,  was  sent  at  the 
expense  of  the  California  fruit-growers  to  Australia  to  try  to  find  and  send 
back  some  effective  predaceous  or  parasitic  enemy  of  the  pest.  As  a  result 
of  this  effort,  a  few  Vedalias  were  sent  to  California,  where  they  were  zeal- 
ously fed  and  cared  for,  and  soon,  after  a  few  generations,  enough  of  the  little 
beetles  were  on  hand  to  warrant  trying  to  colonize  them  in  the  attacked 
orange-groves.     With  astonishing  and  gratifying  success  the  Vedalia  in  a 


Bugs,  Cicadas,  Aphids,  and  Scale-insects         187 

very  few  years  had  so  naturally  increased  and  spread  that  the  ruthless  scale 
was  definitely  checked  in  its  destruction,  and  from  that  time  to  this  has 
been  able  to  do  only  occasionally  and  in  limited  locaHties  any  injury  at  all. 


Fig.  254.— The  fluted  scale,  Tcerya  pitrchasi,  attacked  by  the  Australian  ladybird-beetle, 
Vedalia  cardinalis.  In  lower  left-hand  corner  a  Vedalia  which  has  just  issued  from 
its  pupal  case.  (From  life;  upper  figure  slightly  enlarged;  lower  figiire  much 
enlarged.) 


Of  the  second  group,  the  best-known  scales  are  the  various  species  of  the 
genus  Lecanium  (Fig.  256).  Of  these,  the  olive  or  oleander  or  black  scale, 
L.  olece,  as  it  is  variously  called,  is  the  most  widely  distributed  and  abundant 
and  hence  economically  important.  It  is  a  long-known  species,  having 
been  described  in  Europe  in  1743,  and  it  was  brought  to  this  country  in 
early  days.  The  adult  females  are  blackish,  almost  hemispherical,  rough- 
skinned  creatures,  with  no  external  indication  of  head  or  other  body  divi- 
sions, feet,  antennae,  etc.,  all  these  parts  being  visible  only  from  the  ventral 
aspect,  which  normally  is  closely  applied  to  the  leaf  or  twig.  On  the  back 
may  be  distinguished  three  ridges  forming  an  H.  The  young  are  flatter 
and  light  brown,  but  can  be  recognized  by  their  even  more  distinct  H-mark. 
This  scale  is  found  all  over  the  United  States  and  has  a  wide  range  of  food- 
plants,  garden-bushes  of  all  kinds,  as  well  as  deciduous  and  citrus  fruits 
being  attacked.  In  California  it  is  one  of  the  worst  insect-pests  of  the  olive- 
tree  and  also  one  of  the  worst  of  the  orange  enemies.  It  has  certain  natural 
enemies  in  the  persons  of  various  ladybird-beetle  species,  and  a  few  special 
ladybird-beetles  have  been  imported  from  Australia  and  elsewhere  in  the 
hope  of  repeating  the  signal  Vedalia  success.  Only  a  fair  measure  of  suc- 
cess has  been  achieved.  An  indirect  but  serious  injury  caused  to  plants 
by  the  black  scale  is  due  to  the  germination  in  the  honey-dew  secreted  by 
it  of  the  spores  of  a  fungus,  Capnodium  sp.,  which  spreads  its  felted  mycelia 


J  88  Bugs,  Cicadas,  Aphids,  and  Scale-insects 

over  the  leaf-surfaces,  closing  the  breathing-pores  (stomata)  and  thus  truly 
suffocating  the  plant.     Although  this  scale  species  has  been  known  for  a 

century  and  a  half,  the  males  have 
been  seen  but  few  times  and  in  but 
few  places.  Another  familiar  member 
of  this  group,  which  secretes  a  distinct 
white  waxen  egg-sac,  is  the  maple- 
scale,  Pith'inaria  inmimerahihs  (Fig. 
255),  common  on  maples  in  the 
eastern  states. 

Of  the  third  group,  that  of  the 
most  specialized  (degenerate)  scales, 
the  pernicious  scale,  already  fully 
described,  may  be  taken  as  a  shining 
example.  There  is  a  host  of  these 
armored  scale-insects,  and  few  trees  or 


Fig.  255. 


Fig.  256. 


Fig.  255. — The  maple-scale,  Pulvinaria  innumerahilis.  Females  with  egg-sacs  on  the 
twig;  young  scales  on  under  side  of  leaf,  and  a  single  young  scale,  much  enlarged, 
at  left.     (After  Felt;    natural  size.) 

Fig.  256. — Lecaniiim  scales  attacked  by  the  fungus  Cordyceps  clavidata.  (After  Pettit; 
much  enlarged.) 


shrubs  escape  their  attacks.  The  various  genera  are  mostly  distinguishable 
by  the  shape  of  the  covering  scale,  but  to  determine  the  species  exactly 
requires,  for  many,  careful  examination,  under  high  powers  of  the  microscope, 
of  the  minute  chitinous  processes  which  form  a  fine  fringe  along  the  posterior 
margin  of  the  last  abdominal  segment.  To  make  this  examination  it  is 
necessary  to  remove  the  female  from  under  her  scale,  and  mount  her  cleared 
body  flat  in  balsam  or  glycerine  on  a  glass  slide.  An  important  species 
in  this  group  is  the  red  orange-scale,  Aspidiotus  aiirantii  (Fig.  257),  common 
in  orange-groves  of  southern  California.  A  species  very  closely  resembling 
it  is  A.  ficus,  common  in  the  Florida  groves.  On  pine-needles  one  may 
often  note  small,  narrow  elongate  white  waxen  scales,  with  the  smaller, 
yellowish-brown  exuviae  at  one  end;  these  belong  to  the  widely  spread  species 
Chionaspis    pinifolice.     On   apple-trees   often   occurs   a   roughened    shining 


Bugs,  Cicadas,  Aphids,  and  Scale-insects         189 


Fig.  257. — The  red  orange-scale,  Aspidiotus 
aiirantii.  a,  females,  natural  size,  on  leaf;  b, 
female,  much  enlarged,  removed  from  under 
waxen  scale;  r,  the  scale,  composed  of  wax 
and  exuviae,  much  enlarged;  d,  just  hatched 
young,  much  enlarged;  e,  male,  much  enlarged. 
(After  Jordan  and  Kellogg.) 


blackish  narrow  elongate   curved  scale,  resembling  a  little    an   oyster-shell 

in  miniature;    this  is  the  sometimes  serious  apple-pest,  Mytilaspis  poniorum. 

But  we   have   no    space    to   list 

even     the     most    important     of 

these  degenerate   but   successful 

insect  enemies  of  our  fruit-  and 

foliage-trees. 

The  devising  of  remedies  for 
scale  attack  has  been  given  much 
attention,  and  a  number  of  effec- 
tive means  have  been  discovered 
for  fighting  the  pests.  Probably 
the  most  effective  of  all  is  the 
fumigation  of  infested  orchard- 
trees  by  hydrocyanic  gas.  A 
tent  capable  of  enclosing  a  whole 
tree  is  made,  and  with  this  in 
place  hydrocyanic  gas  is  gen- 
erated under  it  by  pouring 
about  50  oz.  of  water  into  5  oz. 
of  commercial  sulphuric  acid  and 
dropping  in  15  oz.  of  cyanide  of  potassium,  these  amounts  of  acid,  water,  and 
cyanide  being  sufficient  to  fumigate  a  tree  12  ft.  high  by  10  ft.  in  foliage  diam- 
eter; that  is,  to  fumigate  about  1000  cu.  ft.  of  space.  For  larger  or  smaller  trees 
change  the  amounts  of  acid,  water,  and  cyanide  proportionally.  Of  washes 
to  be  applied  in  winter,  when  the  leaves  are  off,  the  best  is  one  made  of  lime 
50  lbs.,  sulphur  50  lbs.,  salt  50  lbs.,  water  150  gals.;  slake  the  lime  with 
water  enough  to  do  it  thoroughly,  and  during  the  process  add  the  sulphur. 
Boil  one  hour  with  water  enough  to  prevent  burning  and  until  the  mixture 
becomes  of  a  deep  amber  color.  Dissolve  the  salt  in  water  enough  to  do 
it  quickly  and  add  slowly  to  the  boiling  mass.  When  all  is  thoroughly 
mixed  together  and  has  actually  boiled  at  least  an  hour  add  water  enough 
to  make  up  150  gals.,  and  apply  by  spraying  or  washing  while  hot.  It 
may  be  safely  applied  when  the  foliage  is  off  to  any  fruit-tree,  garden  shrub, 
or  small  fruit,  and  is  a  very  effective  "scale-killer."  Of  sprays  for  the  leaves, 
crude  petroleum  and  kerosene  emulsion  are  the  best.  For  use,  undiluted 
crude  petroleum  should  be  entirely  untreated  and  of  specific  gravity  of  43° 
or  over  on  the  Beaume  scale.  Smith  has  used  this  oil  safely  on  all  ordinary 
fruit-trees,  but  advises  not  applying  it  to  peach-trees.  At  time  of  apply- 
ing, the  trees'  should  be  dry,  the  oil  of  a  temperature  not  below  60°  Fahrenheit, 
and  the  nozzles  should  throw  a  perpetual  fine  spray.  Kerosene  emulsion  is 
made  by  boiling  J  lb.  of  hard  soap  in  i  gal.  of  water  and  then  adding  2  gals. 


190  Bugs,  Cicadas,  Aphids,  and  Scale-insects 


Fig.  258. — Female  red  orange-scale,  Aspi- 
diotus  aiirantii.  (Photomicrograph  by 
George  O.Mitchell;  much  enlarged.) 


of  kerosene  and  churning  violently  until  a  thick  white  cream  is  formed. 
Let  this  cool  and  jelly;  it  is  the  "stock,"  and  will  hold  for  a  few  weeks;  when 

ready  to  spray,  dilute  stock  with  twelve 
to  fifteen  times  its  own  bulk  of  water 
and  spray  finely  over  the  foliage.  The 
spraying  should  be  done  when  the 
young  scales  are  hatching  and  crawl- 
ing about.  They  are  then  easily  killed 
by  contact  with  even  a  single  fine  drop 
of  kerosene.  For  peach-trees  dilute 
the  stock  twenty  times. 

Some  of  the  scale-insects  present 
such  unusual  conditions  of  structural 
modification  and  of  habits  that  they 
are,  when  first  met  with,  difficult  to 
recognize  as  insects  at  all.  The 
waxen  covering  may  be  so  irregular  and 
curiously  shaped  that  it  gives  no  clue  to  the  character  of  the  enclosed  insect 
(Fig.  261),  but  seems  to  be  simply  a  secretion  of  the  plant  in  which  the  insects 
are  found.  Or  the  globular  shape  and  absence  of  distinct  body-parts  may 
make  the  insects  with  their  hardened  blackish  cuticle  look  like  small  plant- 
galls;  indeed  certain  scale-insect  species  were  first  described  by  botanists  as 
galls.  Some  scales  live  under  ground,  either  in 
ants'  nests  or  independently;  the  curious  so-called 
"ground-pearls,"  small  spherical  shining  bodies 
found  loosely  scattered  in  the  soil  in  certain  tropic 
regions,  and  really  collected  to  be  strung  on  threads 
or  necklaces,  are  the  strangely  modified  bodies  of 
Margarodes  jormicarum,  a  scale-insect.  Taken  alto- 
gether, probably  no  other  family  of  insects  exceeds 
the  Coccidae  in  the  extremes  of  strange  specializa- 
tions. 

Closely  related  to  the  plant -lice  and  scale- 
insects  are  the  mealy- winged  flies,  constituting  the 
family  Aleyrodidae.  The  adults  (Fig.  262),  except 
of  two  or  three  of  the  most  abundant  species,  are 
rarely  seen  even  by  professional  entomologists,  but 
careful  search  will  reveal  in  almost  any  locality  the 
curious  little  box-like  elliptical  bodies  of  the  young 
(Fig.  263),  usually  shining  black,  with  pure-white 
waxen  rods,  filaments,  or  tufts.  Examined  under  a  good  magnifier,  the 
wax-tufted  cases  are  exquisite  objects.     These  young  mealy-wing  flies  look 


•; 


Fig.  259. — Female  rose- 
scale,  Diaspis  r o see. 
(Photomicrograph  b  y 
George  O.  Mitchell; 
much  enlarged.) 


Bugs,  Cicadas,  Aphids,  and  Scale-insects         191 

much  like  scale-insects  and  have  the  same  general  habits.  Provided  with 
a  delicate  long  sucking-beak,  each  individual  remains  fixed  in  one  spot  on 
a  green  leaf,  sucking  up  its  food,  the  plant-sap,  as  it  needs  it.  The  adults 
which  finally  issue  from  the  beautiful  little  cases  have  four  rounded  wings, 
pure  white  or  with  small  dusky  spots  and  golden  yellow,  finely  beaded 
margins;    each  wing  has  but  a  single  vein,  and  is  dusted  with  a  granular 


Tig.  260. — The   California  live-oak  scale,    Ccrococcus   ehrhonii. 

Patterson;    natural  size.) 


(,l'huK)graph  by  Rose 


white  waxen  powder  or  "bloom."  The  tiny  white  or  pale-yellow  eggs 
are  laid  on  leaves  in  a  circle  or  the  arc  of  one,  in  one  or  more  rows,  and 
vary  in  number  from  three  to  thirty;  each  egg  has  a  minute  but  noticeable 
curving  stem.  The  young  hatch  in  from  ten  to  thirteen  days,  and  move 
freely  about,  but  never  seem  to  get  more  than  about  one  inch  from  the 
deserted  shells.  This  activity  lasts  for  from  ten  to  forty  hours;  then 
the  young  attach  themselves  to  the  leaf  by  inserting  the  sucking  proboscis, 


192  Bugs,  Cicadas,  Aphids,  and  Scale-insects 

and  soon  moult,  losing  at  this  time  the  legs  and  antenna.  After  a  second 
moulting,  however,  minute  new  legs  and  antennas  are  again  to  be  seen,  and 
later  the  wing-pads  appear,  and  wings,  legs,  and  antennae  develop  and  grow 
apace;  at  a  last  moulting  the  insect  leaves  the  protection  of  its  beautiful  little 
case  and  flies  away.  Leaving  the  pupa-case  is  a  slow  and  toilsome  process, 
the  imago  often  struggling  for  hours  before  it  is  free  and  ready  for  flight. 


Fig. 


261. — The    Southern   California  oak-scale,   Cerococcus  qiiercus. 
(Photograph  by  Rose  Patterson;    natural  size.) 


All  of  the  pupas  secrete  "honey-dew,"  sometimes  in  such  quantities  that 
the  leaf  around  the  case,  and  the  top  of  the  case  itself,  are  covered  with  it. 
This  honey-dew  is  emitted  from  the  tip  of  a  little  flap-like  anal  structure  called 
the  lingula  (Fig.  266).  The  sweet  liquid  honey-dew,  when  exposed  to  the 
air,  becomes  thick  and  finally  hardens.  The  spores  of  fungi  often  germinate 
in  the  excreted  honey-dew,  and  numerous  ant-species  collect  it  for  food. 


Bugs,  Cicadas,  Aphids,  and  Scale-insects         193 

To  distinguish  any  of  the  various  species  of  mealy-winged  flies  would 
be   a   difficult  matter  for  the   beginning 
entomologist.     Two   special   students  of 


j'.-frA&i^ 


..^ 


Fig.  262. 


Fig.  263. 


Fig.  262. — A  mealy-wing,  Aleyrodes  pruinosa,  adult.     (After  Bemis;   much  enlarged.) 
Fig.  263. — Pupa  of  Aleyrodes  tentacidatus.     (After  Bemis;   much  enlarged.) 


Fig.  264.  Fig.  266. 

Fig.  264. — Pupa  of  Aleyrodes  iridescens.     (After  Bemis;    much  enlarged.) 
Fig.  265. — Pupa-case  of  Aleyrodes  merlini.     (After  Bemis;    much  enlarged.) 
Fig.  266. — Vasiform  orifice  and  Hngula  of  pupa  of  Aleyrodes  merlini.    (After  Bemis;  much 
enlarged.) 

the  American  species  have  published  lists  and  descriptions  of  all  the  kinds 
so  far  known  in  this  country,  namely,  Quaintance  (Bull.  8,  Tech.  Ser.,  Div. 
of  Ent.,  U.  S.  Dept.  Agr.,  1900),  who  has  studied  the  eastern  species,  and 


194         Bugs,  Cicadas,  Aphids,  and  Scale-insects 

Bemis  (Proc.  U.  S.  Nat.  Mus.,  vol.  27,  1904),  who  has  studied  the  Pacific 
Coast  forms.  Mrs.  Bemis  found  twenty  hitherto  unknown  species  of  mealy- 
winged  flies  in  easy  collecting 
range  of  Stanford  University, 
and  these  twenty  kinds  added 
to  those  already  known  make  a 
total  of  sixty  different  species  so 
far  recorded  from  the  United 
States.  There  are  certainly 
many  more  species  yet  unde- 
scribed. 

The  mealy-winged  flies  have 
some,  though  not  a  large,  eco- 
nomic importance.     One  or  two 
species,  Aleyrodes  vaporariorum, 
Fig.    267.— Pupa   of   Aleyrodes   merlini,  showing  etc.,    are   recognized  as  pests  in 
long  waxen  tufts.     (After   Bemis;   much  en-  greenhouses;    one,  A.  citri,  is  a 
larged.)  -  ,  , 

pest    of    oranges,    and   another, 

A.  packardi,  injures  strawberry-plants.  In  all  these  cases  probably  as  much 
injury  is  done  by  the  suffocating  fungus  growth  that  is  supported  by  the 
secreted  honey-dew  as  by  the  direct  sap-sucking  of  the  Aleyrodes  themselves. 
Fumigation  by  hydrocyanic  gas  (see  p.  189)  is  probably  the  best  remedy 
for  the  greenhouse  and  orange  mealy-wings,  and  spraying  with  kerosene 
emulsion  (see  p.   189)  the  best  for  the  strawberry  Aleyrodes. 


SUBORDER  HETEROPTERA. 


Key  to  Families  of  the  Heteroptera  (includes  both  Nymphs  and  Adults). 
(Adapted  from  Woodworth,  with  some  Additions.) 

Antcnnse  shorter  than  the  head:    aquatic  or  shore  insects. 

With  two  ocelli (Toad-bugs.)     Galgulid^.' 

With  no  ocelli. 

Hind  feet  without  claws;    aquatic  insects. 

Prothorax  overlapping  the  head  above (Back-swimmers.)      Notonectid^. 

Head  overlapping  prothorax  above (Water-boatmen.)      Corisid^. 

Hind  feet  with  claws. 

With  two  long  processes  on  tip  of  abdomen  which  can  be  held  together  to  form 

a  tube (Water-scorpions.)     Nepid^. 

Without  abdominal  processes,  or  if  any,  short  flattish  retractile  ones. 

Hind  legs  broad  and  flat (Giant  water-bugs.)      Belostomatid^. 

Hind  legs  slender Naucorid^.'^ 

Antennae  at  least  as  long  as  the  head:    a  few  aquatic  forms,  but  mostly  terrestrial. 
Head  as  long  as  the  whole  thorax (Marsh-treaders.)      Limnobatid^.'^ 


Bugs,  Cicadas,  Aphids,  and  Scale-insects  195 

Head  shorter  than  thorax. 

Last  segment  of  foot  divided  and  the  claws  not  at  the  tip. 

Middle  and  hind  legs  very  long (Water-striders.)     Hydrobatid^. 

Middle   and  hind   legs   not   very  long Veliid^. 

Last  segment  of  foot  not  divided,  and  the  claws  at  the  tip. 
Antennae  3-  or  4-segmented. 

Proboscis   (or  beak)    with  three  joints. 

Body  very  long  and  slender (Thread-legged  bugs.)     Emesid.e. 

Body  not  long  and  slender. 

Femora  of  fore  legs  very  wide (.\mbush-bugs.)     Phymatid.-e. 

Femora  of  fore  legs  not  very  wide.  ^ 

Antennas  of  three  segments (Assassin-bugs.)     Reduviid^. 

Antennae  of  four  segments. 

Feet  of  two  joints,   and  body  very  flat (Flatbugs.)     Aradid^.  v 

Feet  of  three  joints. 

Body  flat  on  top (Bedbugs.)      Acanthiid.e.  ' 

Body  not  flat  on  top (Shore-bugs.)     Saldid.e. 

Proboscis  (or  beak)  with  four  joints. 
Without  ocelli. 

Heavy-bodied  insects,  membrane  of  wings  (in  adults)  with  two  large  cells 
at  the  base  from  which  arise  about  eight  branching  veins  (Fig.  268,  2). 

(Redbugs.)     Pyrrochorid^.  "^ 
Light-bodied  insects;  membrane  of  wings  (in  adults)  with  one  or  two  closed 
cells  at  the  base  and  with  no  longitudinal  veins  (Fig.  268,   i). 

(Leaf-  and  flower-bugs.)     Capsid.e.  '' 
No  ocelli. 

Fore  legs  very  different  from  the  others;   wings  when  present  in  fully  de- 
veloped condition  with  four  long  veins  in  the  membrane  bounding  three 
discal  cells,  which  are  often  open;   from  these  cells  diverge  veins  which 
form  several  marginal  cells  (Fig.  268,    5). .  -  (Damsel-bugs.)     Nabid^. 
Fore  legs  not  very  different  from  the  others. 

Body  very  narrow (.Stilt-bugs.)     Berytid.e. 

Body  not  very  slender. 

Feet  of  two  joints;  wing-covers  (of  adults)  resembling  lace  network. 

(Lace-bugs.)     Tingitid.e. 
Feet  of  three  joints. 

Antennae  inserted  below  an  imaginary  line  drawn  from  the  eye  to  the 
beak ;  membrane  of  wing  (in  adults)  with  four  or  five  simple  veins 
arising  from  its  base,  the  two  inner  veins  sometimes  joined  to  a 
cell  near  the  base  (Fig.  268,  ,5) . .  (Chinch-bug  family.)  Lyg.5:id.e. 
Antennae  inserted  above  an  imaginary  line  drawn  from  the  eye  to  the 
beak;  membrane  of  wings  (in  adults)  with  many  usually  forked 
veins,  springing  from  a  transverse  basal  vein  (Fig.  268,  4). 

(Squash-bug  family.)     C0REID.E. 
Antennae  5-segmented. 
Body  flat  above. 

With  few  or  no  spines  on  the  tibias (Stink-bugs.)     Pentatomid.«. 

With  rows  of  spines  on  the  tibiae (Burrower-bugs.)     Cydnid.e." 

Body  strongly  convex  above. 

Prothorax  round  in  front  and  nearly  straight  behind. 

(Negro-bugs.)     Corimel^nid^.  ' 
Prothorax  hexagonal (Shield-backed  bugs.)     Scutellerid.t.. 


196         Bugs,  Cicadas,  Aphids,  and  Scale-insects 

We  come  now  to  the  "true  bugs,"  representing  twenty-six  families  and 
constituting  the  Heteroptera,  the  largest  of  the  three  suborders  of  the 
Hemiptera.  The  classification  of  the  members  of  this  large  group  into 
families,  by  the  use  of  the  keys  commonly  used  by  entomologists,  demands 
the  recognition  of  such  small  and  obscure  structural  characters  that  I  have 
tried  to  find  some  easier  means  for  the  use  of  the  amateur  and  general  col- 
lector. As  collecting  and  observing  in  the  field  imply  the  discovery  of 
insects  in  their  native  haunts,  we  may  acceptably  make  use  of  constant 
habits  for  a  basis  of  convenient  grouping.  About  one-third  of  the  Heterop- 
terous  families  are  aquatic  in  habitat,  and  of  these  the  members  of  some 
are  to  be  found  on  the  surface  of  pools  and  ponds,  of  others  swimming 


Fig.  268. — Wings  of  Heteroptera,  showing  disposition  of  veins  in  membrane  character- 
istic of  various  families:  i,  Capsidae;  2,  Pyrrhocoridae;  3,  Lygasidas;  4,  Coreida: 
5,  Nabidae;  6,  Acanthiidae.     (After  Comstock.) 

or  crawling  about  below  the  surface,  and  of  two,  only  partly  aquatic, 
on  the  shore,  but  always  by  the  water's  edge.  Some  of  these  aquatic  bugs 
are  to  be  discovered  occasionally  in  flight  far  from  water,  as  the  giant 
water-bugs  and  others,  when  circling  about  electric  lights  or  in  search  of 
new  homes.  But  the  structural  signs  of  the  aquatic  habitat,  legs  flattened 
and  fringed  so  as  to  be  fitted  for  swimming,  will  betray  these  estrays. 
Occasionally,  too,  a  strictly  terrestrial  bug  will  be  found  on  the  surface  of 
a  pool,  but  his  violent  and  obviously  unaccustomed  and  awkward  attempts 
to  swim  to  shore  will  betray  him.  So  we  may  begin  an  acquaintance  with 
the  Heteroptera  by  resorting  to  the  nearest  pond  or  quiet  stream-pool. 

On  the  surface  are  the  familiar  water-striders,  or  skaters.  Their  long, 
spider-like  legs,  narrow  and  black  or  oval  and  yellow  and  black  body, 
and  swift  nervous  running  distinguish  them  from  all  other  bugs.  They 
are  members  of  the  family  Hydrobatidse,  and  the  commoner  species  belong 
to  the  genus  Hygrotrechus  (Figs.  269  and  270).  Upheld  by  the  tense  surface- 
film  of  the  water,  their  feet  only  make  little  dimpled  depressions  in  the  sur- 
face, the  shadows  of  which  may  often  be  seen  on  the  sandy  bottom.  The 
locomotion  is  really  due  to  a  sort  of  surface  rowing  or  gliding,  and  not  a 


Bugs,  Cicadas,  Aphids,  and  Scale-insects  197 

true  running.     The  water-striders  are  predaceous,  capturing  smaller  living 
insects  by  running  or  leaping,  and,  with  the  prey  held  securely  in  the  grasp- 


FiG.  269.  Fig.  270. 

Fig.   269. — Water-strider,  Hygrotrechus  sp.,  adult.    (Twice  natural  size.) 
Fig.   270. — Water-strider,   Hygrotrechus  sp.,  young.   (Twice  natural  size.) 

ing  fore  legs,  piercing  and  sucking  the  blood  of  the  unfortunate  victim,  yet 
alive.     Care  should  be  taken  in  handling  water-striders,  as  the  sharp  beak 


Fig.  271.  Fig.  272.  Fig.  273. 

Fig.  271.— Broad-bodied    water-strider,     Stephania     picta.       (After     Uhler ;      natural 

size.) 
Fig.  272. — An  ocean  water-skater,  Halobates  wiil/ersdotffi,  from  near  Galapagos  Islands. 

(Three  times  natural  size.) 
Fig.   273. — A  marsh-treader,  Limnobates  lineata.     (One  and  one-half  times  natural  size.) 

can  make  a  painful  puncture.     Some  of  them  are  winged  and  some  wing- 
less, and  both  kinds  of  individuals  may  belong  to  the  same  species.     The 


198  Bugs,  Cicadas,  Aphids,  and  Scale-insects 

young  are  usually  short-bodied,  and  of  course  wholly  wingless  or  with  small 
wing-pads  only.  In  late  autumn  the  water-striders  conceal  themselves 
in  the  mud  beneath  leaves  or  rubbish  or  at  the  bottom  of  the  pool  under 
roots  or  stones  to  hibernate,  coming  out  again  with  the  first  warm  days  of 
spring.  The  whitish  elongate  eggs  are  laid  in  early  spring,  being  attached 
by  a  sort  of  glue  to  the  leaves  and  stems  of  aquatic  plants.  Some  species 
have  several  generations  each  year.  Water-striders  are  easily  kept  in 
aquaria  if  the  sides  are  high  enough  above  water  to  prevent  their  leaping 
out.  In  bringing  them  in  from  the  pond  covered  pails  should  be  used,  or 
they  may  be  enclosed  in  any  small  dry  receptacle  not  air-tight.  They  are 
easily  drowned  if  shaken  about  in  a  covered  pail  of  water. 

A  few  interesting  Hydrobatids,  belonging  to  the  genus  Halobates  (Fig. 
272),  live  on  the  surface  of  the  ocean,  especially  in  subtropic  and  tropic 
latitudes.  They  are  said  to  feed  on  the  juices  of  dead  animals  floating  on 
the  surface,  and  probably  attach  their  eggs  to  floating  seaweed  (Sargassum). 

Certain  stout-bodied  insects,  widest  across  the  prothorax  and  with  much 
shorter,  stouter  legs,  members  of  the  family  Veliidae,  are  sometimes  to  be 
found,  running  about  on  the  surface  of  the  water,  always  near  the  shore. 
They  can  also  run  readily  on  land,  which  the  true  water-skaters  cannot 
do.  Also  certain  other  slender  insects,  about  ^  inch  long,  with  thin  long 
legs  and  hair-like  antennae  and  long  cylindrical  head,  are  to  be  found  on 
top  of  the  water.  But  they  creep  slowly  about  on  the  surface  or  on  the 
soft  mud  of  the  shore,  and  are  found  mostly  where  plants  are  growing  in 
quiet  water.  These  are  marsh-treaders,  Limnobates  lineata  (Fig.  273), 
and  this  species  is  the  only  representative  of  the  family  Limnobatidae  known 
in  this  country. 

Swimming  and  diving  about  beneath  the  surface  are  the  water-boatmen 
(family  Corisidas)  and  back-swimmers  (family  Notonectidae).  The  water- 
boatmen  (Fig.  274)  are  oval,  finely  mottled,  greenish  gray  and  black,  and 
swim  with  back  uppermost.  They  are  all  small,  some  only  \  inch  long, 
none  over  half  an  inch.  The  back-swimmers  have  the  back  shaped  like  the 
bottom  of  a  boat,  swim  with  the  back  always  down,  and  are  usually  bluish 
black  and  creamy  white  in  color.  Both  of  these  kinds  of  water-bugs  are 
predaceous,  feeding  on  smaller  aquatic  creatures.  But  the  beak  of  the  back- 
swimmers  is  much  longer  and  stronger  than  that  of  the  water-boatmen, 
and  can  make  a  painful  sting  on  one's  finger.  Both  kinds  have  the  hind 
legs  long  and  specially  flattened  and  fringed  to  serve  as  oars,  and  both  kinds 
come  to  the  surface  for  air,  although  the  back-swimmers  come  up  far  more 
often  than  the  water-boatmen.  The  air  taken  up  clings  as  a  silvery  bubble 
to  a  large  part  of  the  body  both  under  the  folded  wings  and  on  the  under 
side,  being  held  there  by  fine  hairs  which  form  a  pile  like  that  on  velvet. 
A  supply  of  air  is  thus  taken  down  by  the  bugs,  which  enables  them  to  remain 


Bugs,  Cicadas,  Aphids,  and  Scale-insects  199 

for  some  time  under  water.  Both  kinds  are  attracted  to  lights,  and  may 
often  be  seen  in  summer  about  outdoor  electric  lamps.  The  eggs  of  the 
water-boatmen  are  attached  to  the  submerged  stems  of  aquatic  plants,  while 
those  of  the  back-swimmers  are  inserted  in  the  stems,  the  female  having 
a  sharp  ovipositor  for  this  purpose.  In  winter  the  adults  lay  dormant  in  the 
mud  at  the  bottom  of  ponds  or  streams. 

All  the  species  of  water-boatmen  in  the  country  belong  to  the  genus 
Corisa,  while  there  are  three  genera  of  back-swimmers,  Notonecta,  with 
hind  legs  longer  than  the  others  and  fore  wings  but  little  longer  than  the 
abdomen,  being  the  most  abundant  and 
wide-spread.  Plea  is  a  genus  with  all  the 
legs  ahke,  while  Anisops,  the  third  genus, 
has  the  wing-covers  usually  much  longer 
than  the  abdomen.  The  complete  life- 
history  of  no  member  of  either  of  these 
families  of  water-bugs  is  yet  known,  but  it 
ought  not  to  be  a  difficult  matter  for  some 
persistent  observer  to  add  this  needed  ^^^  ^^^  _^  wat^oatman,  Corisa 
knowledge  to  entomological  science.  Both  sp.  (After  Jenkins  and  Kellogg; 
water-boatmen  and  back-swimmers  live  twice  natural  size.) 
readily  in  aquaria,  and  make  thoroughly  interesting  creatures  to  observe 
at  leisure.  The  characteristic  habits  of  obtaining  air,  swimming,  capturing 
prey,  etc.,  can  all  be  learned  from  the  observation  of  aquarium  specimens. 
The  capacity  of  the  water-boatmen  to  remain  below  the  surface  in  pure 
water  for  protracted  periods,  apparently  indefinitely  long,  needs  to  be  better 
understood  than  it  is  at  present,  and  should  be  an  interesting  problem  for 
some  observer  of  aquarium  life. 

Creeping  or  crawling  about  among  the  stems  and  leaves  of  submerged 
plants  in  reedy  and  grassy  quiet  waters,  and  feeding  on  smaller  insects,  may 
sometimes  be  found  certain  small  flat-bodied  oval  insects  with  front  legs 
thickened  and  fitted  for  grasping.  These  are  water-creepers,  or  Naucoridae, 
only  five  species  of  which  are  known  in  this  country.  The  single  species 
found  in  the  eastern  states  is  known  as  Pelocaris  jemorata,  and  is  about 
J  inch  long,  broadly  oval  in  shape,  and  yellowish  brown  in  color.  The 
other  species  belong  to  the  genus  Ambrysus  and  are  restricted  to  the  western 
states.     The  life-history  of  no  member  of  the  family  is  known. 

Occasionally  there  will  be  seen  resting,  or  swimming  slowly  about,  at  the 
bottom  of  the  pool  a  veritable  giant  bug,  2f  inches  long  and  i  J  inches  wide, 
with  heavy  strong  legs  flattened  and  oar-like  and  the  front  ones  held  out 
arm-like  and  bent  in  an  expectant  grasping  position.  Again,  in  the  warm 
sultry  evenings  of  midsummer  and  early  autumn,  among  the  swarms  of 
insects  attracted  to  the  electric  lights  on  the  streets,  one  or  two  great  bugs 


200  Bugs,  Cicadas,  Aphids,  and  Scale-insects 


will  go  whirling  around  the  bright  globe  of  light,  casting  large  fleeting 
shadows  on  the  ground  below.  The  giant  in  the  pool's  depth  and  the  giant 
in  the  giddy  swarm  at  the  light  are  one  and  the  same,  viz.,  the  giant  water- 
bug  or  electric-light  bug,  a  member  of  the  family  Belostomatidae.  Most 
of  its  life  is  passed  in  the  water;  it  hatches  from  eggs  deposited  under  water, 
lives  its  whole  immature  life  in  the  pool,  and  only  comes  out  for  a  short  flying 
season  to  find  mates  or  a  new  pool.  The  two  largest  species  of  this  family, 
both  common  in  this  country,  are  Belostoma  americana  (Fig.  275)  and  Benacus 

griseus,  distinguishable  by  the  fact  that 
the  former  has  a  groove  on  each  front 
femur  for  the  tibia  to  fit  in  when  folded. 
A  smaller  kind,  more  oval  in  shape,  is  the 
commonest  form  on  the  Pacific  slope. 
This   is    Serphus   diJatatus,    the    toe-biter. 


Fig.  275. 

Fig.   275. — The  giant  water-bug  or  electric-light  bug,   Belostoma  americana.     (Natural 

size.) 
Fig.  276. — The  western  water-bug,  Serphus  sp.;    male  with  eggs  deposited  on  its  back 

by  female.     (Natural  size.) 


which  is  i\  to  j\  inches  long  and  f  to  |^  inch  wide.  In  the  East  a  still 
smaller  form,  Zaitha  fluminea,  is  common.  This  is  a  little  less  than  i 
inch  long.  All  these  Belostomatids  are  fiercely  predaceous,  capturing 
aquatic  insects,  tadpoles,  etc.,  and  are  armed  with  a  short,  strong,  pointed 
beak  with  which  a  serious  puncture  can  be  made.  They  secrete  themselves 
beneath  stones  or  rubbish,  whence  they  dart  out  on  their  victims.  A  con- 
siderable amount  of  poisonous  saliva  enters  the  wound  made  by  the  beak, 
and  probably  aids  in  overcoming  the  prey.  The  larger  species  attack 
young  fish,  seizing  them  with  their  strong  grasping  fore  legs  and  sucking 
their  blood.  They  can  do  much  injury  in  carp-ponds  or  in  garden-pools 
where  fishes  are  kept  for  pleasure.     The   females  of  the   species  of  the 


Bugs,  Cicadas,  Aphids,  and  Scale-insects         201 

smaller  genera  Serplnis  and  Zaitha  have  the  curious  habit  of  gluing  their 
eggs  upright,  in  a  single  layer,  on  the  back  of  the  unwilling  male  (Fig.  276). 
For  a  long  time  it  was  believed,  and  is  so  stated  in  most  entomological  books, 
that  the  female  deposited  the  eggs  on  her  own  back,  but  it  was  discovered 
by  Snodgrass  that  the  female  Serphits  had  no  ovipositor  capable  of  reach- 
ing to  her  back,  and  by  Miss  Slater  that  the  female  Zaitha  is  in  similar  con- 
dition. Miss  Slater  observed  the  egg-laying  by  aquarium  specimens.  The 
male  struggles  against  the  indignity,  but  is  actually  overcome  by  the  female. 
Another  small  aquatic  family  of  few  species  is  that  .of  the  Nepidae,  or 
water-scorpions.  These  dirty  brown,  stick-like  insects  can  be  distinguished 
from  other  aquatic  Hemiptera  by  the  long  slender  respiratory  tube,  made 

up  of  separable  halves  each  grooved  on  its 
inner  face,  which  projects  from  the  tip  of 
the  abdomen.  Rather  sluggish  in  habit, 
they  lie  at  the  bottom  of  a  shallow  pool  and 
lift  this  respiratory  tube  up  so  that  its  open 
tip  reaches  the  surface.  They  are  preda- 
ceous  and  have  the  fore  legs  modified  for 
seizing  prey,  the  other  legs  being  fitted  for 
walking  or  crawling  over  the  bottom.  There 
are  two  common  genera  in  the  family:  Nepa, 
with  flattened  oval  body  less  than  three  times 
as   long  (not  including  respiratory  tube)  as 


Fig.  277. 


Fig.  278. 


Fig.   277. — A  water-scorpion,   Ranatra  jiisca.     (One  and  one-half  times  natural  size.) 
Fig.   278. — Eggs  of  the  water-scorpion,  Ranatra  jusca.     (After  Pettit;    enlarged.) 


broad,  and  Ranatra  (Fig.  277),  with  elongate  slender  body  more  than  five 
times  as  long  as  broad.  Like  the  giant  water-bugs  the  water-scorpions 
lie  in  wait  for  their  prey,  trusting  to  their  inconspicuous  color  and  partial 
concealment  in  the  mud  and  rubbish  of  the  bottom  to  hide  them  from 
approaching  victims. 


20  2  Bags,  Cicadas,  Aphids,  and  Scale-insects 

By  the  edge  of  pond  or  stream  may  be  found  representatives  of  two  other 
small  families,  most  striking  in  appearance  and  manner,  the  dark-colored, 
squat,  broad,  rough  bodied,  big-eyed,  leaping  toad-bugs  (Galgulidae)  and 
the  smaller,  soft,  long-oval,  long-legged,  running  shore-bugs  (Saldidae). 
One  species  of  toad-bug,  Galgidiis  ocidatiis  (Figs.  279  and  280),  is  common 
all  over  the  country  and  may  often  be  found  in  considerable  nimibers  on 
the  muddy  banks  of  streams  and  ponds.  It  lives 
upon  other  insects,  which  it  catches  by  creeping 
slowly  to  within  a  short  distance  and  then  suddenly 
leaping  upon  and  seizing  them  with  its  strong  front 


-nw- 


Fig.  279. 


Fig.  280. 


Fig.   279. — The  toad-bug,   Galgulus  oculatus.     (Three  times  natural  size.) 
Fig.   280. — Three  toad-bugs,  Galgulus  oculatus,   "coming  on."     (From  life;    three  times 
(natural  size.) 


legs.  Toad-bugs  vary  in  general  coloration  with  the  mud  or  soil  they  are 
on,  so  as  to  harmonize  with  the  ground  color  and  thus  be  undistinguishable. 
The  shores  of  a  small  pond,  Lagunita,  on  the  campus  of  Stanford 
University,  vary  much  in  ground  color,  three  shades,  namely,  reddish,  slaty 
bluish,  and  mottled  sand  color,  being  the  principal 
ones,  and  toad-bugs  collected  from  the  banks  of 
this  pond  show  very  noticeably  all  these  distinct 
schemes  of  color.  The  shore-bugs  (Saldidae)  are 
represented  by  but  one  genus,  Salda  (Fig.  281),  of 
thirty  or  more  species,  in  our  country.  The  insects  are 
about  y\-  inch  long,  smooth-bodied,  and  narrower  than 
the  toad-bugs,  blackish  with  white  or  yellow  markings, 
and  have  long  slender  antennae.  They  prefer  stream 
or  pond  banks  which  are  weedy  or  grassy  and  offer 
They  are  common  also  on  seabeaches.  They  feed 
on  drowned  flies  and  other  insects,  from  which  they  suck  the  blood.  They 
thus  do  some  good  as  scavengers. 

The  preceding  ten  families  include  all  of  the  aquatic  and  strictly  shore- 
inhabiting  Hemiptera.  The  remaining  sixteen  families  of  the  suborder 
Heteroptera,  as  well  as  all  the  families  in  both  other  suborders,  are  terres- 
trial, being  found  for  the  most  part  (the  Parasita  wholly  excepted)  on  vegeta- 
tion  where  food,  either  the  juices  of  the  plants,  or  the  blood  of  other  plant- 


FiG.  281.  —  A  shore- 
bug,  Salda  sp.  (Six 
times  natural  size.) 

good  hiding-places. 


Bugs,  Cicadas,  Aphids,  and  Scale-insects         203 

feeding  insects,  is  found.  This  difference  in  food-habit  is  accompanied 
by  more  or  less  obvious  structural  differences.  In  the  predaceous  forms 
the  fore  legs  are  usually  spined  and  fitted  for  seizing  and  holding  the  living 
victims,  the  other  legs  fitted  for  swift  running,  the  beak  is  stout,  firm,  and 
sharp-pointed,  the  eyes  are  often  large,  protuberant,  and  flashing  bright, 
and  there  is  a  general  unmistakable  air  of  ferocity  about  these  miniature 
bloodthirsty  dragons  of  the  garden  shrubbery. 

Five  of  the  terrestrial  families  of  Heteroptera  are  predaceous,  the  remain- 
ing eleven  being  composed  of  sap-suckers,  although  in  one  or  two  of  these 
families  a  few  species  seem  to  have  acquired  a  taste  for  blood-sucking. 

The  largest  predaceous  family  is  that  of  the  assassin-bugs,  wheel-bugs, 
and  soldier-bugs,  the  Reduviida;.  More  than  fifty  genera  belonging  to 
this  family  are  represented  in  this  country,  but  so  little  are  the  bugs  col- 
lected or  even  noticed  by  amateurs  (or  professionals  either,  for  that  matter) 
that  but  few  of  the  species  can  be  said  to  be  at  all  familiarly  known.  And 
to  use  the  word  "familiarly"  in  this  connection  is  to  indulge  in  the  figure 
of  speech  known  as  hyperbole. 

The  Reduviids  have  an  unmistakable  look  of  ferocity,  small  and  insig- 
nificant creatures  as  they  are.  The  eyes  are  usually  large  and  protuberant, 
looking  like  a  pair  of  shining  black  beads  set  on  the  small  outstretched  head. 
The  beak,  3-segmented,  is  strong,  sharp-pointed,  and  large  for  the  small 
head  that  carries  it,  and  it  projects  forward  in  a  suggestively  eager  way. 
While  the  ground  or  body  color  of  the  bugs  is  usually  black,  they  are  often 
conspicuously  marked  with  blood-red  and  sometimes  with  yellow.  The 
wingless  young  are  in  many  species  wholly  red.  A  few  years  ago  the  news- 
papers were  filled  with  references  to  a  much  dreaded  "kissing-bug"  (one 
of  the  Reduviids),  the  name  being  a  satire  on  the  stinging  and  poisoning 
capabilities  of  the  bug's  beak  or  mouth.  The  sting,  i.e.,  piercing  by  the 
beak,  of  the  kissing-bug,  and  of  all  other  Reduviids,  is  poisonous  because 
of  the  injection  of  saliva  into  the  wound,  and  this  poisoning,  which  makes 
such  a  wound  often  very  painful  and  sometimes  rather  serious  to  man,  must 
be  paralyzing  and  fatal  to  the  more  usual  insect  victims  of  the  assassin-bugs. 
The  usual  "kissing-bug"  of  the  newspapers  is  the  masked  bedbug-hunter, 
Opsicoetus  personatus,  an  insect  from  ^  to  f  inch  long,  blackish  brown, 
with  prothorax  strongly  constricted  in  the  middle  and  longitudinally 
grooved  along  the  middle  of  the  upper  surface.  The  entomologists' 
name  for  this  insect  comes  from  the  fact  that  the  young  exude  a  sticky 
substance  over  the  body  to  which  dust,  Hnt,  etc.,  adhere  so  as  to  cover  or 
mask  the  body,  and  that  the  bugs  enter  houses  and  prey  on  bedbugs,  cock- 
roaches, and  flies.     The  bite  or  sting  is  unusually  poisonous  and  severe. 

Another  assassin-bug  which  forces  its  acquaintance  on  us  is  the  "big 
bedbug,"    or  cone-nose,   Conorhiniis  sanguisugus   (Fig.  282),  which  comes 


204         Bi-igs,  Cicadas,  Aphids,  and  Scale-insects 

into  houses  primarily  to  drink  human  blood.  It  is  about  an  inch  long, 
pitchy  brown  or  black,  with  long  narrow  head,  and  with  bright  red  patches 
on  the  sides  of  the  body  and  on  the  base  and  apex  of  the  fore  wings.  These 
insects,  whose  normal  outdoors  food  consists  of  various  insects,  often  noxious 
ones,  as  locusts  and  potato-beetles,  are  specially  common  in  the  South,  where 
Comstock  says  they  not  infrequently  sting  children.  The  banded  soldier- 
bug,  Milyas  cinctus,  is  a  common 
wide-spread  friend  of  the  farmer, 
preying  on  many  kinds  of  noxious 
insects.  It  is  yellow  in  all  stages  of 
development  with  conspicuous  fine 
transverse  black  bands  on  legs  and 
antennae.  It  roams  about  over  plants 
from  early  summer  to  late  autumn, 
Fig.  282.-The  blood-sucking  cone-nose  benevolently  assimilating  the  blood 
Conormnus  sangmsugiis.     (After  Howard  ■'   _  ° 

and  Marlatt;    natural  size.)  of  its  various  insect  cousins.      It  glues 

its  eggs  to  the  bark" of  trees  and  covers  them  with  a  protecting  water-proof  gum. 
Another  fairly  well-known  member  of  this  family  is  the  wheel-bug,  Prionidus 
cristatus,  especially  common  in  the  South.  The  full-grown  bug  is  about 
an  inch  long,  black,  and  has  on  its  thorax  a  thin  convex  crest  with  nine  teeth. 
This  is  the  "wheel."  The  little  jug-shaped  eggs  are  laid  in  six-sided  single- 
layered  masses  of  about  seventy,  which  are  glued  to  the  bark  of  trees,  or  on 
fence-rails,  the  sides  of  houses,  etc.  The  young  are  blood-red,  with  black 
on  the  thorax.  The  wheel-bugs  are  specially  beneficial  because  they  are 
among  the  few  predaceous  insects  that  prey  on  the  well-protected  hairy 
caterpillars  that  infest  our  shade  and  orchard  trees. 

Closely  related  to  the  Reduviids  are  the  curious  and  readily  recognized 
thread-legged  bugs,  Emesida.  The  few  known  species  have  the  body  very 
slender  and  long,  and  the  legs  and  antennae  simply  like  jointed  threads. 
The  fore  legs,  however,  are  spined  and  fitted  for  seizing  prey.  The  common 
species,  Emesa  longipes  (Fig.  283),  has  the  body  a  little  less  than  i^  inches 
long,  each  middle  and  hind  leg  a  little  more  than  ij  inches  long,  and  the 
wings  when  folded  not  reaching  the  tip  of  the  abdomen.  It  is  clayey  brown 
in  color  with  a  reddish  tinge  above.  Howard  says  that  one  of  the  thread- 
legged  bugs  frequents  spiders'  webs  and  robs  the  spiders  of  their  prey.  The 
damsel-bugs  (Nabida?)  are  another  small  family  of  predaceous  insects  which 
usually  lurk  among  flowers  and  foliage  where  they  capture  small  insects, 
but  which  in  autumn  may  often  be  seen  running  about  on  sidewalks  and 
elsewhere  about  houses,  probably  looking  for  winter  hiding-places.  One 
of  the  commonest  and  most  conspicuous  damsel-bugs  is  the  shining  jet-black, 
yellow-legged  species  Corisciis  siihcoleoptrahis.  The  wings  and  wing-covers 
(in  most  individuals)  are  reduced  to  mere  scales,  the  body  is  wide  and  plump 


Bugs,  Cicadas,  Aphids,  and  Scale-insects  205 

behind,  tapering  forward  to  the  narrow  prothorax  and  head.  It  is  about 
^  inch  long.  The  air-bush  bug,  Phyniata  wolfii,  a  rough,  horny-bodied, 
yellowish-green    insect  with  brown  or  blackish  band  across  the  abdomen, 

is  about  i  inch  long  or  less  and  the  body  is 
rather  like  some  scaly  seed.  The  abdomen  is 
curiously  widened  behind  into  two  thin,  angular, 
scale-like  expansions.  It  conceals  itself  in 
flower-cups  and  captures  the  nectar-sucking 
insect  visitors.     It  is  very  strong  and  overcomes 


Fig.  283. 


Fig.  284. 


Fig.  283. — A  thread-legged  bug,  Emesa  longipes.     (Natural  size.) 

Fig.  284. — A  damsel-bug,  Nabis  fusca.     (After  Bruner;    natural  size  indicated  by  line.) 


insects,  as  small  butterflies,  bees,  and  wasps,  much  larger  than  itself. 

Another  small  family  of  blood-sucking  bugs  is  the  Acanthiidae,  of  which 
the  most  familiar  is  the  wingless  degenerate  pest,  the  bedbug,  Acanthia 
lectularia  (Fig.  285),  world-wide  in  distribution  and  detestation.  To  the 
fortunate  few  who  have  not  at  one  time  or  other  been  forced  to  a  personal 
acquaintance  with  this  bug  species  it  may  be  told  that  it  is,  when  full-grown 
and  fairly  nourished,  about  \  inch  long,  reddish  brown  in  color,  and  broad 
and  flat  bodied.  Small  wing-scales  or  pads  can  be  seen  on  close  examina- 
tion of  specimens.  The  bugs,  both  immature  and  adult,  can  run  quickly 
and,  because  of  their  "flatness,  can  conceal  themselves  in  narrow  cracks.  In 
such  crevices  in  bedsteads,  in  walls  and  floors,  they  hide  by  day,  coming 
out  at  night  to  feed.  In  spring  the  females  lay  about  two  hundred  oval 
white  eggs  in  lots  of  fifty  at  a  time  in  their  haunts  in  crevices.     The  eggs 


2o6         Bugs,  Cicadas,  Aphids,  and  Scale-insects 

hatch  in  about  a  week  and  the  young  become  full  grown  in  about  three  months 
moulting  five  times  during  growth,  but  active  and  capable  of  "finding"  for 
themselves  from  birth.  In  the  northern  states  there  is  but  one  generation 
a  year.  The  disagreeable  bedbuggy  odor  is  produced  by  a  secretion  of 
small  glands  opening,  in  the  adult,  on  the  under  side  of  the  body.  Another 
species  of  Acanthia  attacks  chickens,  pigeons,  swallows,  and  bats,  and 
Lugger  found  this  species,  A  hirundinis,  or  another  similar  one,  attacking 
in  daytime  the  pupils  in  a  school  in  western  Minnesota.  The  best  remedy 
is  the  free  application  with  a  quill-feather  of  a  saturated  solution  of  corrosive 
sublimate  (Poison!)  in  alcohol  to  all  cracks  and  crevices  in  infested  bed- 
steads, walls,  floors,  and  ceilings.  When  bedbugs  cannot  be  found  hiding 
in  bedsteads  in  daytime  and  yet  mysteriously  appear  every  night,  it  is  often 
because  they  drop  from  the  ceiling. 


Fig.  2 


Fig.  286. 


Fig.  28s. — The  bedbug,  Acanthia  lectularia;    young  at  left  and  adult  at  right.     (After 

Riley;    natural  size  indicated  by  line.) 
Fig.    286. — A    predaceous    leaf-bug,    Lyctocoris   fitchii.     (After    Lugger,     natural    size 

indicated  by  line.) 


In  this  family  belong  several  small  inconspicuous  insects  called  flower- 
bugs,  which  do  much  good  by  their  persistent  preying  on  noxious  insects. 
The  best-known  species  is  the  insidious  flower-bug,  Triphleps  insidiosus, 
which  preys  on  the  chinch-bug.  Another  species  is  Lyctocoris  fitchii 
(Fig.  286),  which  preys  on  the  larvae  of  certain  destructive  wood-bormg 
beetles. 

The  remaining  famihes,  eleven,  of  American  bugs  find  their  food  and 
drink,  for  the  most  part,  in  the  juices  of  living  plants.  Like  the  blood- 
sucking bugs,  they  need  for  their  feeding,  and  have,  a  well-developed  suck- 
ing-beak.    From  the  tip  of  the  sheath  (labium)  can  be  thrust  out  the  foui 


Bugs,  Cicadas,  Aphids,  and  Scale-insects         207 

sharp  stylets  or  lancets  (maxillae  and  mandibles)  to  lacerate  the  plant-tissues, 
and  then  the  pharyngeal  pump  sucks  up  from  the  wound  the  flowing  sap. 
When  too  many  pumps  are  drawing  away  too  much  sap,  the  leaves  wilt, 
yellow,  and  die.  When  too  many  leaves  wilt,  the  plant  starves  to  death. 
And  if  the  leaves  happen  to  be  the  corn-leaves,  and  the  pumpers  chinch- 
bugs,  we  have  the  result  estimated  for  us  (by  the  official  U.  S.  statistician)  in 
millions  of  dollars  of  loss,  as  in  1887,  when  this  particular  loss  in  the  Missis- 
sippi Valley  states  was  $60,000,000. 

The  eleven  plant-feeding  families  of  true  bugs  (Heteroptera)  can  be 
distinguished  by  the   following  key: 

Antennae  4-segmented. 

Fore  wings  reticulated  and  of  uniform  thin  substance  throughout Tingitid.e. 

Fore  wings  of  various  forms  or  absent,  but  not  reticulated,  and  not  of  uniform  thin 
substance  throughout. 

Beak  3-segmented ;   body  greatly  flattened Aradid.e. 

Beak  4-segmented;    body  not  greatly  flattened. 

Membrane  (apical  area)  of  fore  wings  with  one  or  two  closed  cells  at  base,  but 

otherwise  without  veins  (Fig.   268) Capsid.«. 

Membrane  of  fore  wings  with  four  or  five  simple  or  anastomosing  longitudinal 
veins  arising  from  the  base;    or  with  a  larger  number  of  veins  arising  from 
a  cross-vein  at  the  base. 
Ocelli  wanting;    membrane  of  fore  wings  with  two  large  cells  at  the  base,  and 

from  these  arise  branching  veins  (Fig.  268) Pyrrhocorid^. 

Ocelli  present. 

Head  with  a  transverse  incision  in  front  of  the  ocelli Berytid^. 

Head  without  transverse  incision. 

Membrane  of  fore  wings  with  four  or  five  simple  veins  arising  from  the 
base   of  the  membrane;    the   two  inner  ones  sometimes  joined  to  a 

cell  near  the  base   (Fig.   268) Lyg.eid^. 

Membrane  of  fore  wings  with  many  usually  forked  veins  springing  from 

a  transverse  basal  vein  (Fig.  268) Coreid.s:. 

Antennae  5-segmented. 

Scutellum  nearly  flat,  narrowed  behind. 

Tibiae  unarmed  or  furnished  with  very  fine  short  spines Pentatomid^. 

Tibiae  armed  with  strong  spines  in  rows Cydnid^. 

Scutellum  very  convex  and  covering  nearly  the  whole  of  the  abdomen. 

Small,   black  (sometimes  with  bluish  or  greenish  tinge) CoRiMELiENiDyE. 

Not  black Scutellerid^. 

The  first  of  the  families  in  the  above  table,  the  Tingitida?,  includes  the 
curious  small  lace-bugs  (Fig.  287),  readily  recognized  by  the  dehcate  gauze- 
or  lace-like  appearance  of  the  back,  due  to  the  uniform  thin  and  reticulated 
character  of  the  fore  wings  and  of  the  wing-like  expansions  of  the  prothorax. 
About  twenty-five  species  are  found  in  this  country,  all  being  plant-feeders, 
living  mostly  on  shrubs  and  trees.  Hawthorn-bushes  and  oak-,  sycamore-, 
and  butternut-trees  all  have  particular  species  of  lace-bugs  on  them.     In  the 


2o8         Bugs,  Cicadas,  Aphids,  and  Scale-insects 


south  cotton  and  beans  are  also  attacked  by  lace-bugs.  The  most  familiar 
eastern  species  is  the  hawthorn  lace-bug,  Corythuca  arcuata,  which  is  com- 
mon on  the  leaves  of  hawthorn-bushes.  The  bugs  keep  almost  exclusively 
on  the  under  side  of  the  leaves.  Th'e  eggs  are  laid  in  small  groups  on  the 
leaves,  each  egg  being  imbedded  in  a  little  bluntly  conical  mass  of  a  brown 
sticky  substance  which  hardens  soon  after  egg-laying  and  looks  much  like 

a  small  fungus.  The  top  of  the  glistening 
white  egg  can  be  seen,  however,  by  looking 
down  on  one  of  these  brown  masses.  The 
young  is  broadly  oval  and  flattened  in  shape, 
brown  and  spiny,  and  moults  five  times  in  its 
development.  The  torn,  delicate,  whitish 
exuviae  (cast  skins)  stick  to  the  leaf.  The 
adults  hibernate  under  the  fallen  leaves 
on  the  ground  beneath  the  bushes.  In 
Cahfornia  a  similar  lace-bug,  Corythuca  sp., 
(Fig.  287),  infests  the  Christmas  berry, 
Heteromeles  arhiitijolia,  a  plant  whose  clusters 
of  bright  red  berries  take  the  place  in  Cali- 
fornian  Christmas-tide  decorations  of  the 
holly  of  the  East.  The  eggs  (Fig.  287)  are 
deposited  in  the  same  way  as  the  hawthorn 
lace-bugs',  and  the  life-history  is  practically 
the  same.  But  because  the  California  winter 
is  much  less  severe  and  the  Christmas  berry 
is  covered  with  green  leaves  all  the  year,  active  lace-bugs,  young  as  well 
as  adult,  can  always  be  found  on  the  bushes.  Lace-bugs,  small  as  they 
are,  injure  any  plant  on  which  they  gather  in  numbers,  by  the  continual 
draining  away  of  the  sap.  Spraying  the  infested  bushes  or  trees  with 
kerosene  emulsion  (p.   189)  will  kill  the  insects. 

The  flattest  of  all  the  bugs,  flatter  than  the  bedbugs  even,  are  the 
curious  members  of  the  small  family  Aradidae.  They  live  in  the  cracks  or 
beneath  the  bark  of  decaying  trees,  and  their  dull  brown  color  and  flat  leaf- 
like body  make  them  very  difficult  to  distinguish  when  at  rest  in  their  hiding- 
places.  The  glistening  white  eggs  are  laid  under  the  bark.  The  flatbugs 
are  often  mistaken  for  bedbugs,  as  they  are  nocturnal  and  are  often  found 
in  log  cabins.  But  they  probably  feed  exclusively  on  plant-sap,  being 
especially  attracted  to  mills  and  recently  felled  trees,  where  they  suck  up  the 
sap  exuding  from  the  cut  or  sawed  logs.  Aradus  cinnamomens  (Fig.  288) 
is  about  the  same  size  as  a  full-grown  bedbug  and  is  reddish  in  tinge,  so  that 
superficially  it  does  much  resemble  a  bedbug.  But  all  the  adult  flatbugs 
have  wings,  while  all  the  bedbugs  are  wingless. 


Fig.  287. — The  lace-bug,  Cory- 
thuca sp.,  of  the  California 
Christmas  berry,  Heteromeles 
arbiitijolia;  at  bottom,  eggs  on 
small  tubercles  on  leaf;  above, 
just-hatched  young,  intermediate 
stage,  and  adult.  (Eight  times 
natural  size.) 


Bugs,  Cicadas,  Aphids,  and  Scale-insects         209 

The  flower-bug  family,  CapsicUe,  contains  two  hundred  and  fifty  known 
North  American  species,  almost  all  of  which,  however,  are  small  and  incon- 
spicuous. They  mostly  five  in  pastures,  meadows,  gardens,  and  along 
roadsides,  on  the  grasses,  weeds,  and  herbaceous  flowering  plants  of  these 
places,  but  some  infest  woody  plants  and  a  few  species  do  much  damage 
to  garden  and  orchard  shrubs  and  trees.  A  few  species  are  predaceous, 
and  Howard  has  seen  one  species  sucking  the  eggs  of  the  imported  elm-leaf 
beetle,  a  great  pest  of  our  elm-trees.  The  structural  characteristic  by  which 
they  can  most  readily  be  distinguished  from  other  bugs  is  the  presence  of 
one  or  two  closed  cells  and  no  longitudinal  veins  in  the  membrane  (apical 
half)  of  each  fore  wing  (Fig.  268).     When  examined  closely  many  of  these 


Fig.  288 


Fig. 


290. 


Fig.  288.— a  flalbug,  Aradits  cinnamomeus.     (After  Lugger;    enlarged  about  six  times.) 
Fig.  289. — The  tarnished  plant-bug,  Lygus  prate.nsis.     (Five  times  natural  size.) 
Fig.   29c. — The  four-lined  leaf-bug,  Pmcilocapsus  lineatus ;   at   right,  eggs  deposited  in 

plant-stem.     (Figure  of  insect  original,  enlarged  three   and  a  half  times;    of  eggs, 

after  Slingerland,  and  much  enlarged.) 


little  bugs  will  be  seen  to  be  elaborately  patterned  and  beautifully  colored, 
and  their  body  outhne  is  trim  and  graceful.  They  are  active  and  quick 
to  escape  from  the  collecting-net.  (The  best  way  to  collect  them  is  by  sweep- 
ing rankly  growing  herbage  with  a  short-handled  stout  net.)  Among  the 
most  abundant  and  wide-spread  Capsids  of  economic  importance  is  the 
tarnished  plant-bug,  Lygiis  pnitensis  (Fig.  289),  which  attacks  many  cul- 
tivated plants,  as  the  sugar-beet,  strawberry,  pear-,  plum-,  apple-,  quince-, 
and  other  fruit-trees.  It  is  about  \  inch  long,  and  ranges  from  dull  dark 
brown  to  yellowish  or  greenish  brown.  A  yellowish-white  V-shaped  mark 
on  the  scutellum  is  its  most  characteristic  marking.  It  hibernates  in  the 
adult  stage,  under  fallen  leaves  or  in  any  rubbish,  and  comes  out  in  the  spring 
to  pierce  and  suck  sap  from  tender  buds  and  leaves.  The  four-lined  leaf- 
bug,  Poecilocapsus  hneatus  (Fig.  290),  a  small  bright-yellow  bug  with  head 


2 1  o         Bugs,  Cicadas,  Aphids,  and  Scale-insects 

and  under  side  of  body  orange-red,  and  four  black  stripes  on  the  back,  is 
abundant  in  the  east  and  north,  and  is  known  to  attack  at  least  fifty  dif- 
ferent kinds  of  cultivated  plants.  It  is  especially  familiar  as  a  currant-pest. 
The  eggs  are  deposited  in  sHts  cut  lengthwise  in  plant-stems.  The  best 
general  remedy  for  these  bugs  is  the  jarring  of  branches  of  the  bushes  over  a 
dish  partly  filled  with  kerosene.  Comstock  says  that  the  most  abundant 
flower-bug  in  the  northeastern  states  is  a  small  greenish-yellow  species  with 
two  longitudinal  black  stripes  extending  from  the  eyes  over  the  prothorax 
and  scutellum.  It  is  long  (|  inch)  and  narrow  (y^j  inch),  is  found  in  the 
grass  in  meadows,  and  its  name  is  Leptoterna  dolobrata.  The  injury  done 
by  all  Capsids  is  by  the  sucking  of  sap  through  small  punctures  and  prob- 
ably also,  in  some  cases,  the  pouring  of  poisonous  saliva  into  the  plant- 
tissues  through  the  punctures.  The  attacked  leaves  or  buds  wilt,  turn  yellow, 
and  finally  wither.  One  of  the  beneficial  Capsids  is  the  glassy-winged  bug, 
Hyaliodes  vitripennis,  a  beautiful  small  yellowish-white  insect  with  almost 
transparent  fore  wings,  with  a  dash  across  the  apex  of  these  wings,  and  pro- 
thorax  red.  It  feeds  on  other  insects,  and  especially  on  the  grape-phyl- 
loxera in  its  leaf-inhabiting  form.  Lopidea  media  is  an  abundant  yellowish- 
red  and  black  Capsid  which  has  learned  to  like  human  blood.  When  it 
cannot  have  blood  it  is  content  with  the  sap  of  wild  gooseberries. 

The  family  Pyrrhocoridae  is  a  small  family  of  comparatively  large  and 
stout  bugs,  often  conspicuous  by  their  colors,  of  which  red  and  black  are 
the  most  usual.  They  may  be  recognized  by  their 
having  the  membrane  (apical  half)  of  the  fore  wings 
provided  with  two  large  basal  cells  from  which 
several  branching  veins  arise  (Fig.  268).  They  are 
commonly  known  as  "redbugs,"  and  the  twenty- 
five  species  found  in  our  country  belong  mostly  to 
the  south  and  west.  The  commonest  species  in 
the  north  is  Largus  succindus  (Fig.  291),  a  rusty 
blackish-brown  bug  about  half  an  inch  long,  with 
yellowish  or  pinkish-orange  margins  on  the  front 
two-thirds  of  the  back,  and  a  transverse  stripe  of 
similar  color  across  the  base  of  the  prothorax.     The 

Fig.  291.— Redbug,  Lar-  young  are  steel-blue  with  a  small  bright-red  dash  on 
eus  succinctus.     (Twice    ,  -     ,,  ,    ,  ,     ,  .11,  , 

natural  size.)  DQ.'&e.    01    the  abdomen   between  the   backward-pro- 

jecting wing-pads.  This  species  ranges  from  New 
Jersey  to  California  and  south  into  Mexico.  The  commonest  species  of 
the  southern  states,  and  one  of  great  economic  importance,  is  the  red- 
bug  or  cotton-stainer,  Dysderciis  suturellus,  which  does  much  damage 
by  piercing  the  stems  and  bolls  of  the  cotton-plant  and  sucking  the  juices, 
but  does   even   more  damage  by  staining  the  cotton  in  the  opening  bolls 


Bugs,  Cicadas,  Aphids,  and  Scale-insects  211 

by  its  reddish-yellow  *  excretions.  Howard  says  that  experiments  have 
been  made  with  this  insect  looking  towards  its  use  commercially,  and  that 
the  whole  substance  of  the  insect  can  be  converted  into  a  rich  orange- 
yellow  dye  which  is  readily  fixed  on  woolens  or  silk  by  the  alum  mordant 
liquor.  The  cotton-stainer  is  a  handsome  bug,  reddish  in  color  with  pale 
brown  fore  wings  striped  with  pale  yellow.  The  young  are  bright  red  with 
black  legs.  Comstock  says  that  this  insect  also  punctures  oranges  in 
Florida,  so  that  the  fruit  begins  to  decay  and  drops  from  the  tree.  The 
insects  can  be  trapped  by  laying  chips  of  sugar-cane  about  the  cotton-field  or 
orange-grove:  the  bugs  will  gather  about  these  chips  and  may  be  scalded 
to  death. 

One  of  the  largest  families  of  true  bugs  is  the  Lygseidae,  made  notorious 
by  a  small  and  obscure  representative  of  it,  which,  according  to  the  estimate 
of  the  United  States  Entomologist,  causes  our  country  an  annual  loss  of 
$20,000,000.  This  insect  is  the  chinch-bug,  the 
worst  pest  of  corn,  and  one  of  the  worst  of  wheat 
and  other  small  grains.  Nearly  two  hundred  species 
of  Lygaeids  occur  in  this  country,  and  most  of 
them  may  fairly  be  called  noxious  insects.  The 
family's  structural  characteristic  most  readily  noted 
is  the  presence  of  but  four  or  five  simple  longitudinal 
veins  in  the  membrane  (apical  half)  of  the  fore  wings 
(Fig.  268).  The  antennae  rise  rather  from  the  under 
than  the  upper  side  of  the  head,  and  all  of  the  members  \'W^^fJ/  \^ 

of  the  family  have  ocelli  (simple  eyes).  While  most 
of  the  Lygaeids  are  small  and  inconspicuous,  a  few  fig.  292. — LygcBus  turci- 
are  comparatively  large  and  bright-colored.  The  ^"•^-  (After  Lugger; 
milkweed-bug,   Oncopelius    fasciatus,  about    §   inch 

long,  orange  above  with  most  of  head  and  prothorax  except  the  margins 
black,  and  a  broad  black  band  across  the  middle  of  the  fore  wings  and 
large  black  blotch  on  their  tips,  is  a  common  showy  bug  on  various 
species  of  milkweed.  An  odd-looking,  long-necked,  common  member  of 
the  family  is  Myodocha  serripes.  It  is  about  f  inch  long,  with  head  long 
and  narrow,  expanding  in  front,  and  rising  from  a  bell-shaped  prothorax, 
the  rest  of  the  body  being  elongate  and  narrow.  It  is  black,  with  the 
margins,  sutures,  veins,  and  some  spots  on  the  wing-covers  yellow.  It  is 
common  in  meadows  and  thin  woods,  where  it  keeps  half  concealed  under 
fallen  leaves  and  twigs.  In  the  south  a  small  species,  Pamera  longula,  \ 
inch  long,  dark  brown  with  lighter  brown  on  prothorax  and  fore  wings,  is 
abundant,  feeding  mostly  on  meadow  plants. 

Among  the  many   smaller  species,   the   chinch-bug,   Blissiis  leucopterns 
(Fig.  293),  is  the  best  known  and  most  important.     It  is  found  nearly  all 


212  Bugs,  Cicadas,  Aphids,  and  Scale-insects 

over  the  United  States  and  in  Canada,  but  the  great  losses  occasioned  by 
it  occur  mostly  in  the  corn-growing  states  of  the  Mississippi  Valley,  where 
it  has  been  known  as  a  pest  since  1823.  I  have  seen  great  corn-fields  in 
this  valley  ruined  in  less  than  a  week,  the  little  black  and  white  bugs  mass- 
ing in  such  numbers  on  the  growing  corn  that  the  stalk  and  bases  of  the 
leaves  were  wholly  concealed  by  the  covering  of  bugs.  The  chinch-bug 
when  adult  is  about  ^  inch  long,  blackish  with  the  fore  wings  semi-trans- 
parent white  and  with  a  conspicuous  small  trian- 
gular black  dot  near  the  middle  of  the  outer  margin. 
The  very  young  are  red,  but  become  blackish  or  gray 
as  they  grow  older.  The  bug  is  injurious  in  all 
stages,  young,  half  grown,  and  adult.  The  life- 
history,  in  Kansas,  is  as  follows:  The  eggs  are  laid 
in  the  spring  (from  middle  of  March  to  middle  of 
May)  by  bugs  which  have  hibernated  in  the  adult 
stage.  They  are  laid  a  few  at  a  time,  perhaps  five 
hundred  in  all  by  each  female.  The  young  "red- 
bugs"  begin  work  in   the   wheat-fields,  and  usually 

jTjg     2  ,  'pj^g   chinch-   remain  in  the  wheat   until   harvest  (last  of  June  to 

bug,  Blissus  leucopterus.   middle  of  July),  when  the  destructive  host  moves  into 

(Nine      times      natural    .1       r-   u       r  j  •  Ti 

gj^g  X  the  fields  of  young  and  growmg  corn.     It  requires 

about  six    weeks  for    the    maturing    of    the    bugs. 

The   adults  now   pair  and   the   cycle   of  a   new   generation  begins.      The 

perfect  insects  of  this  generation  are  those  which  pass  through  the  winter 

and  lay  the  eggs  the  following  spring  for  the  next  year's  first  brood.     It 

is  highly  probable  if  not  certain  that  a  third  brood  often  appears  in  Kansas. 

The  chinch-bug,  though  winged,  uses  its  powers  of  flight  but  little,  and  its 

migrations  from  wheat-  to  corn-fields  in  July  are  usually  on  foot.     The  wings 

are  used  to  some  degree  at  pairing-time. 

The  remedies  for  chinch-bug  attacks  include  the  gathering  together  in 

winter  of  all  rubbish,  old  corn-leaves,  dead  leaves,  etc.,  in  which  the  old  bugs 

hibernate,  and  burning  it,  which  will  destroy  many  parent  bugs,  thereby  largely 

lessening  the  spring  brood.     Disputing  the  entrance  of  the  bugs  into  the 

field,  when  migrating  on  foot,  by  plowing  furrows  around    the   field  and 

pouring  coal-tar  or  crude  petroleum   into   these  moats,   is  often   effective. 

There  are  several  natural  remedies,  namely,  the  attacks  of  predaceous  insects, 

as  aphis-lions,  ladybird-beetles,  and  others,  and  the  attacks  of  some  birds, 

as  the  common  quail.     Most  effective  of  all,  however,  is  the  rapid  spread 

.in  a  crowded  field  of  a  parasitic  fungus,  Sporotrichiini  globtdijerum,  which 

kills  the  bugs  by  the  wholesale.     This  fungus  cannot  grow  rapidly  except 

in  moist  warm  weather,  and  the  bugs  thrive  especially  in  dry  weather.     So 

the  rapid  spreading  and  effective  killing  by  this  disease  depends  on  favorable 


Bugs,  Cicadas,  Aphids,  and  Scale-insects  2 1  3 

meteorological  conditions.  The  "chinch-bug  cholera"  is  well  established 
all  through  the  Mississippi  Valley,  but  it  can  be  artificially  spread  by  dis- 
tributing dead  and  infected  bugs  in  fields  where  it  has  not  begun  to  develop. 
This  method  is  followed  in  several  of  the  corn-  and  wheat-growing  states 
whose  entomolgists  keep  on  hand  a  supply  of  this  fungus — it  can  be  artifi- 
cially cultivated  on  various  nutrient  media  in  the  laboratory — to  send  out 
to  farmers  on  request.  The  work  was  begun  by  Professor  F.  H.  Snow  of 
the  University  of  Kansas,  and  though  in  the  beginning  its  beneficial  results 
were  overrated,  there  is  no  doubt  that  much  good  has  come  from  this  wide- 
spread attempt  to  disseminate  artificially  the  "chinch-bug  disease." 

The  family  Coreidoe,  to  which  the  squash-bug,  the  box-elder  bug,  and 
certain  other  more  or  less  familiar  insects  belong,  is  another  of  the  larger  true 
bug  families,  being  represented  in  this  country  by  about  two  hundred  species. 
In  this  family  the  membrane  (apical  half)  of  the  fore  wings  is  furnished 
with  many  veins,  most  of  which  arise  from  a  cross-vein  near  the  base  (Fig. 
268),  and  the  antennae  arise  from  the  upper  side  of  the  head.  The  squash- 
bug,  Anasa  tristis  (Fig.  294),  ill-favored  and  ill-smelling,  is  a  pest  of  squashes 
and  pumpkins  all  over  the  country. 
It  is  brownish  black  above,  with  some 
yellow  spots  along  the  edges  of  the 
body,  and  dirty  yellow  below.  It  hiber- 
nates in  the  adult  stage,  comes  out  in 
early  spring,  and  lays  its  eggs  on  the 
young  sprouts  or  leaves  of  squash-  and 

pumpkin-vines.     The  young  hatch  in        f— iiiigKai-^-  %    mnw    n  .n 

about  two  weeks  and  at  first  are  green, 
but  soon  turn  brown  and  grayish. 
They  suck  the   sap   from  the  growing         Fig.  294.  Fig.  295. 

vine,  and  soon  stunt  them  or  even  kill  Fig.  294.— A  squash-bug,  Anasa  tristis. 
^,  ™,  ■,      ■     .  .      4.    4.U  (Natural  size.) 

them.  The  remedy  is  to  protect  the  p^,  ap^.-The  box-elder  bug,  Leptocoris 
young  plants  by  means  of  frames  cov-  trivittatus.  (Twice  natural  size.) 
ered  with  netting.  After  the  plants  get  well  started  the  bugs  cannot  injure 
them  so  easily.  The  box-elder  bug,  Leptocoris  trivittatus  (Fig.  295),  a  con- 
spicuous black  insect  with  three  bright-red  broad  lines  on  the  prothorax 
and  the  fore  wings,  with  edges  and  veins  of  a  more  dingy  red,  has  become 
familiar  with  the  increased  planting  of  box-elder  trees  in  gardens  and  streets. 
In  the  Mississippi  Valley  and  in  the  plains  states  these  box-elders  are  much 
used  for  shade  and  ornamental  trees  because  of  their  hardiness,  and  with  this 
increased  supply  of  trees  the  box-elder  bugs  have  come  to  be  very  abundant. 
In  late  autumn  they  gather  under  sidewalks  or,  often,  in  stables  and  houses 
to  pass  the  winter,  and  have  led  many  housewives  to  think  a  new  and 
enlarged  kind  of  bedbug  had  come  to  town.     The  bug  lives  on  the  sap  of 


214         Bugs,  Cicadas,  Aphids,  and  Scale-insects 

the  trees  until  winter,  and  it  does  not  care  for  much  food  while  hibernating. 
As  its  mouth  is  a  sucking-beak,  it  cannot  possibly  injure  hard  and  dry  house- 
hold substances,  as  some  housewives  claim.  Another  Coreid,  not  uncom- 
mon, is  the  cherry-bug,  Metapodius  femoralus,  which  punctures  cherries  to 
suck  the  juice  from  them.  It  is  dark  brown  with  a  rough  upper  surface, 
and  its  hind  femora  are  curved  thick  and  knobby,  while  the  hind  tibite  have  a 
blade-like  expansion.  The  leaf-footed  plant-bug,  Leptoglossus  oppositiis, 
is  a  Coreid  destructive  to  melon-vines,  recognizable  by  the  remarkable 
leaf-like  expansion  of  its  hind  tibiae.  A  similar  leaf-footed  species,  Lepto- 
glossus phyllopus,  occurs  in  the  south,  where  it  attacks  oranges  and  other 
subtropical  fruits. 

Allied  to  the  Coreidse  is  the  family  Berytidse,  or  stilt-bugs,  of  which  but  a 
few  species  are  known  in  this  country.  One  of  these,  Zalysus  spinosiis, 
is  common  all  over  the  country  east  of  the  Sierra  Nevadas.  It  is  about  ^ 
inch  long,  very  slender,  and  light  yellowish  brown  in  color,  and  is  found 
"in  the  undergrowth  of  oak  woods."     Its  life-history  is  not  known. 

The  remaining  four  families  of  true  bugs  are  distinguished  by  their 
possession  of  5-segmented  (instead  of  4-segmented)  antennae  (with  a  few 
exceptions)  and  by  having  the  body  broad,  short,  and  flatly  convex, — shield- 
shaped  it  may  then  fairly  be  called, — or  very  convex  or  turtle-shaped.  Almost 
all  of  these  bugs  are  exceptionally  ill-smelling  and  have  on  this  account 
got  for  themselves  the  inelegant  but  expressive  popular  name  of  stink-bugs. 
As  a  matter  of  fact  the  giving  off  of  offensive  odors  is  characteristic  of  most 
of  the  terrestrial  true  bugs,  the  squash-bug,  chinch-bug,  and  others  being  just 
about  as  malodorous  as  the  so-called  stink-bugs. 

Of  these  four  families  of  shield-bodied  bugs,  one,  the  Pentatomidae,  is 
represented  in  this  country  by  numerous  species,  but  the  other  three  con- 
tain but  one  or  two  genera  each.  While  most  of  the  Pentatomids,  or  stink- 
bugs,  are  plant-feeders,  a  few  are  blood-sucking,  while  some  feed  indifferently 
on  either  animal  or  plant  juices.  Several  of  the  more  common  Pentatomids 
are  green,  as  the  large  green  tree-bug,  Nezara  pennsylvanica,  nearly  f  inch 
long,  flattened,  with  grass-green  body  margined  with  a  light  yellow  Une, 
occurring  in  the  fall  on  grape-vines  and  other  plants;  and  the  bound  tree- 
bug,  Lioderma  ligata,  much  like  Nezara,  but  with  broader  body  edging  of 
pale  red  and  with  a  pale-red  spot  on  the  middle  of  its  back,  found 
often  abundantly  on  berries  and  hazel.  Other  common  stink-bugs  are 
brown,  as  the  various  species  of  Euchistes.  Still  others  are  conspicuously 
colored  with  red  and  black,  as  the  abundant  small  species  Cosmopepla  car- 
nijex,  about  \  inch  long,  shining  black  with  red  and  orange  spots,  most  con- 
spicuous of  which  are  a  transverse  and  a  longitudinal  line  in  the  back  of 
the  prothorax.  The  best  known  and  most  destructive  of  these  bizarre- 
colored  stink-bugs  is  the  harlequin  cabbage-bug,  or  calico-back,  Miirgantia 


B 


PROPERTY  OF 

ugs,  Cicadas,  Ajmrds^  and  Scale-insects         2 1 


histrionica  (Fig.  296),  black  with  red  or  orange  or  yellow  strips  and  spots, 
which  has  gradually  spread  from  its  native  home  in  Central  America  to 
all  except  the  northern  states  of  our  country.  It  feeds  on  cabbages,  radishes, 
turnips,  and  other  garden  vegetables,  and  often  does  great  damage  in  market- 
gardens.     In  California  it  has  to  be  fought  vigorously  in  the  large  market- 


-■^liv 


Fig.  296. 


Fig.  297. 


.ni^ 


Fig.  296.— The  harlequin  cabbage-bug,  Mur:^anlia  histrionica.  (Twice  natural  size.) 
Fig.    297.— The   spined   tree-bug,    Podisus   spinosus.     (After   Lugger;     natural   length, 

I  inch.) 
Fig.  298.— a  stink-bug,  Pentatoma  jtiniperina.     (One  and  one-half  times  natural  size.) 

and  seed-gardens  of  the  Santa  Clara  Valley.  The  adults  hibernate,  and  in 
the  spring  each  female  lays  about  twelve  eggs  in  two  parallel  rows  on  the 
under  surface  of  the  young  leaves.  The  young  bugs,  which  are  pale  green, 
hatch  in  three  days,  and  in  two  or  three  weeks  are  full  grown.  There  can 
thus  be  several  generations  m  a  season. 

Among  the  predaceous  or  blood-sucking  stink-bugs  the  species  of  the 
genus  Podisus  are  especially  common  and  effective.  They  destroy  many 
injurious  insects.  Podisus  spinosus  (Fig.  297),  the  most  familiar  species, 
may  be  recognized  by  the  prominent  spine-like  processes  projecting  from 
the  posterior  lateral  angles  of  the  prothorax.  The  large  gray  tree-bugs 
of  the  genus  Brachymena  with  roughened  spiny  back  and  grayish  body- 
color  may  be  found  resting  on  the  bark  of  trees,  with  whose  color  and  rough- 
ness they  harmonize  so  thoroughly  as  to  be  nearly  indistinguishable.  They 
feed  indifferently  on  either  plant-sap  or  the  blood  of  other  insects. 

Representatives  of  the  three  other  families  of  shield-backed  or  stink- 
bugs  will  be  rarely  found  by  general  collectors.  The  flea-like  negro-bug, 
Corimelcena  pulicaria  (family  Corimelffinidffi),  is  a  tiny,  very  malodorous, 
polished  black  species  often  abundant  on  blackberries  and  raspberries, 
with  which  it  often  goes  to  market  and  even  farther!    The  burro wer-bugs 


21 6  Bugs,  Cicadas,  Aphids,  and  Scale-insects 

(family  Cydnidie)  have  an  oval  rounded  or  elliptical  blackish  body  with  the 
front  legs  more  or  less  flattened  and  fitted  for  digging.  They  are  found 
burrowing  in  sandy  places  or  under  sticks  or  stones.  They  probably  suck 
the  sap  from  plant-roots. 

SUBORDER    PARASITA. 

The  members  of  the  suborder  Parasita  are  the  disgusting  and  discom- 
forting degenerate  wingless  Hemiptera  known  as  lice.  They  live  parasitic- 
ally  on  the  bodies  of  various  mammals,  the  ones  most  familiar  being  the 
three  species  found  on  man,  all  belonging  to  the  genus  Pediculus,  and  the 
several  species  of  the  genus  Haematopinus  found  on  domestic  animals,  as 
dogs,  horses,  cattle,  sheep,  etc.  Both  these  genera  together  with  a  few 
others  found  on  various  wild  animals,  belong  to  the  Pediculidse,  the  single 
family  of  the  suborder  represented  in  this  country.  The  only  other  family, 
Polycterridae,  contains  but  two  species,  both  found  on  bats,  one  in  Jamaica 
and  the  other  in  China. 

All  the  Pediculids  are  wholly  wingless,  have  the  mouth-parts  fused  to 
form  a  flexible  sucking-tube,  and  the  feet  provided  with  a  single  strong  curved 
claw  which  specially  adapts  them  for  clasping  and  clinging  to  hairs.     The 


Fig.  299. 


Fig.  300. 


Fig.    299. — The   head-louse   of  man,   Pediciilns  capitiis.     (After    Lugger;    natural   size 

indicated  by  line.) 
Fig.  300. — The  body-louse  of  man,  Pediculus  vestimenii.     (After  Lugger;    natural  size 

indicated  by  line.) 


sucking-beak  has  been  described  by  Uhler  as  "a  fleshy  unjointed  rostrum 
capable  of  great  extension  by  being  rolled  inside  out,  this  action  serving 
to  bring  forward  a  chaplet  of  barbs  which  imbed  themselves  in  the  skin  to 


Bugs,  Cicadas,  Aphids,  and  Scale-insects  217 

gi\-e  a  firm  hold  for  the  penetrating  bristles  arranged  as  chitinous  strips  in 
a  long,  slender,  flexible  tube  terminated  by  four  very  minute  lobes  which 
probe  to  the  capillary  vessels  of  a  sweat-pore."  Of  the  three  species  of 
Pediculus  infesting  unclean  persons,  P.  capitus  (Fig.  299),  the  head-louse, 
is  longer  than  wide,  whitish  with  faint  dark  markings  at  the  sides  of  the 
thorax  and  abdomen;  P.  vestimenti  (Fig.  300),  the  body-louse,  is  of  the 
same  shape  and  general  aj)pearance,  but  when  full  grown  has  the 
dorsal  surface  marked  with  dark  transverse  bands;  while  P.  inguinalis 
(Fig.  301),  the  crab-louse,  has  the  body  as  wide  as  long,  with  strong 
legs   spreading   out   laterally   so  as   to   increase   the   apparent   width    very 


Fig.  301. 


Fig. 


Fig.  30J 


Fig.  301. — The  CTa.b-\ouse.oi  ma.n,  Phthirius  inguinalis.     (.'\fter  Lugger;  much  enlarged.) 
Fig.   302. — Egg  of  crab-louse,  Phthirius  inguinalis.     (After  Lugger;    much  enlarged.) 
Fig.   303. — Sucking  dog-louse,  HcBmatopinus  pilijerus  Burm.     (After  Lugger;    natural 
size  indicated  by  line.) 


much.  The  eggs  (Fig.  302),  called  "nits,"  of  these  lice  are  whitish  and  are 
glued  to  the  hairs  (in  the  case  of  P.  capitus)  or  deposited  in  folds  of  the 
clothing  {P.  vestimenti),  and  the  young,  when  hatched,  resemble  the  parents 
except  in  size.  The  whole  life  is  passed  on  the  body  of  the  host.  The  prime 
remedy  for  these  disgusting  pests  is  cleanliness.  Various  sulphur  and  mercu- 
rial ointments  will  kill  the  insects. 

The  lice  of  the  domestic  animals  belong  to  a  different  genus,  Hasma- 
topinus,  but  are  very  similar  in  appearance  and  structure  to  the  head-lice 
of  man.  H.  pilijerus  (Fig.  303),  of  dogs,  is  about  yV  inch  long,  reddish 
yellow,  and  with  the  abdomen  thickly  covered  with  fine  hairs  and  minute 
tubercles;  H.  eiirysternus  (Fig.  304),  the  short-nosed  ox-louse,  of  cattle, 
is  from  |  inch  to  \  inch  long,  fully  half  as  wide,  with  the  head  bluntly 
rounded  in  front  and  nearly  as  broad  as  long;  H.  viiuli,  long-nosed  ox-louse. 


21 8         Bugs,  Cicadas,  Aphids,  and  Scale-insects 

also  of  cattle,  is  about  ^  inch  long  and  not  more  than  ^  as  wide,  with  long 
slender  head,  narrow  in  front;  H.  urius  (Fig.  305),  of  hogs,  is  \  inch  long, 
being  one  of  the  largest  of  the  sucking-lice,  with  broad  abdomen  and  long 
head,  and  gray  in  color,  with  the  lateral  margins  of  head,  thorax,  and  abdo- 


FiG.  304. 


Fig.  305. 


Fig.  304. — Short-nosed  cattle-louse,  Hamatopinus  eiirysternus.     (After  Lugger;    natural 

length  1.5  mm.) 
Fig.  305. — The  hog-louse,  HcBtnatopinus  urius.     (After  Lugger;    natural  size  indicated 

by  line.) 


men  black;  H.  pedalis,  the  sheep-foot  louse,  found  only  on  the  legs  and 
feet  of  sheep,  below  the  long  wool,  has  a  short,  wide  head  and  same  general 
shape  as  the  short-nosed  ox-louse;  H.  asini,  of  horses,  of  about  same  size 
as  the  short-nosed  ox-louse,  but  with  long  and  slender  head  with  nearly 
parallel  sides;  H.  spimdosus,  of  the  rat,  small,  Hght  yellow,  and  with  the 
head  projecting  very  little  in  front  of  the  antennae  and  the  thorax  very  short ; 
H.  acanthopus,  of  the  field-mouse,  resembling  the  rat-louse  in  color  and 
shape,  but  larger;  H.  ventricosus,  of  rabbits  and  hares,  thick-bodied  and 
short-legged  and  with  abdomen  nearly  circular;  H.  aniennatus,  of  the 
fox-squirrel,  with  long  slender  body  and  curious  curved  tooth-like  process 
on  basal  segment;  H.  sciuropteri,  of  the  flying  squirrel,  with  slender  light- 
yellow  body,  and  head  as  broad  as  long,  and  with  front  margin  nearly 
straight;  H.  siituralis,  of  the  ground-squirrels  and  chipmunks,  with  short 
broad  golden-yellow  body.  The  eggs  of  all  these  forms  are  glued  to  the 
hair  of  the  hosts,  the  young  louse  escaping  by  the  outer  or  unattached  end 
and  immediately  beginning  an  active  blood-sucking  life.     The  most  effective 


Bugs,  Cicadas,  Aphids,  and  Scale-insects         219 


and  feasible  remedy  in  the  case  of  thin-haired  animals,  as  swine  and  horses, 
is  the  appUcation  of  a  wash  of  tobacco-water  or  dilute  carbohc  acid,  or  of 
an  ointment  made  of  one  part  sulphur  to  four  parts  lard,  or  kerosene  in 
lard,  or  of  a  liberal  dusting  with  wood  ashes  or  powdered  charcoal;  in  the 
case  of  thick-haired  animals,  as  cattle,  the  best  remedy  is  fumigation  by 
enclosing  the  animal  in  a  sac  or  tent  with  the  head  left  free,  and  burning 
sulphur  or  tobacco  inside  the  sack.  One  to  two  ounces  of  tobacco  and 
exposure  of  twenty  to  thirty  minutes  for  each  cow  have  been  found  effective. 

A  BRIEF  account  of  the  curious  little  insects  known  as  thrips  may  be 
appended  here  to  the  chapter  on  the  Hemiptera  (Fig.  307).     These  narrow- 


FiG.  306. 


Fig.  307. 


Fig.  306. — The  sheep-louse,  Hamatopinus ovis,  female  and  egg. 

size  of  insect  indicated  by  line;    egg  much  enlarged.) 
Fig.  307. — Thrips,  Phorithrips  sp.     (Much  enlarged.) 


(After  Lugger;  natural 


bodied,  fringe-winged,  yellowish  or  reddish  brown  or  blackish  little  creatures 
can  be  most  readily  found  in  flower-cups,  which  they  frequent  for  the  sake 
of  sucking  the  sap  from  the  pistils  and  stamens  or  the  delicate  sepals 
and  petals.  Some  of  them  move  slowly  when  disturbed,  but  others  run 
quickly  or  leap,  and  nearly  all  show  an  odd  characteristic  bending  up  o^ 
the  tip  of  the  slender  abdomen.  This  movement  is  usually  preparatory 
to  flight  (in  the  case  of  winged  individuals),  and  is  believed  to  be  the  means 
of  separating  and  combing  out  the  fringes  which  border  both  fore  and  hind 
margins  of  each  wing.  There  are  fine  spines  on  the  sides  of  the  abdomen, 
and  the  movement  of  the  abdomen  seems  to  draw  the  fringe-hairs  through 
these  comb-like  rows  of  spines.  The  thrips  vary  in  size  from  -^-^  to  \  of 
an  inch,  and  may  be  certainly  known  by  their  narrow  fringed  wings  (when 


2  20         Bugs,  Cicadas,  Aphids,  and  Scale-insects 


present),  which,  when  the  insect  is  at  rest,  are  laid  back  along  the  abdomen 
unfolded,  and  parallel  or  slightly  overlapping  at  the  tips.  Only  about  forty 
species  are  yet  known  in  this  country,  but  as  practically  only  one  entomol- 
ogist has  attempted  to  make  a  systematic  study  of  the  group  and  his  speci- 
mens were  mostly  collected  in  a  single  locality  (Amherst,  Massachusetts), 
it  is  certain  that  many  species  are  yet  to  be  found  and  named.  This 
entomologist,  Hinds,  has  published  in  a  recent  paper  (Contrib.  to  a  Mon- 
ograph of  the  Thysanoptera  of  N.  A.,  Proc.  U.  S.  Nat.  Mus.,  vol.  xxvi, 
1902)  practically  all  that  is  known  of  our  American  species,  and  I  have 
largely  drawn  on  his  paper  for  the  present  short  account. 

Although  the  thrips  used  to  be  classified  as  a  family  of  the  order  Hemip- 
tera,  they  are  now,  and  rightly,  assigned  to  an  order  of  their  own,  called 
Thysanoptera  (fringe-wings).  This  separation  is  due  tc  the  peculiar  charac- 
ters of  their  mouth-parts  and  of  the  feet,  and 
to  the  interesting  character  of  their  develop- 
ment, which  is  apparently  of  a  sort  of  tran- 
sitional condition  between  incomplete  and 
complete  metamorphosis.  The  food  of  the 
thrips  is  either  the  sap  of  living  plants  or 
moist,  decaying  vegetable  matter,  especially 
wood  and  fungi.  The  mouth-structure  in  ac- 
cordance with  this  food  habit  is  of  a  sucking 
tvpe,  with  mandibles  and  maxilke  modified  to 
be  needle-like  to  pierce  the  plant  epidermis. 
But  the  mouth-parts  are  curiously  asym- 
metrical, the  right  mandible  being  wholly 
wanting  and  the  upper  lip  being  more  ex- 
panded on  one  side  than  the  other  (Fig.  308). 
The  peculiarity  in  the  life-history  consists  in 
a  quiescent,  non-food-taking  stage  like  the 
pupal  stage  in  insects  of  complete  metamor- 
phosis, but  before  reaching  this  stage  well- 
developed  external  wing-pads  have  appeared, 
just  as  happens  in  the  case  of  immature 
insects  of  incomplete  metamorphosis.  Finally, 
the  peculiar  character  of  the  feet  is  due  to  the 
presence  of  a  small  protrusile  or  expansile 
membranous  sac  or  bladder  at  the  tip  of  the 
tarsus,  instead  of  claws  or  fixed  pads,  which  seero,s  to  play  a  not  well 
understood  function  in  the  holding  on  by  the  insect  to  the  leaf  or 
flower  parts  which  it  may  have  occasion    to  visit.      The    bladder   seems 


Fig.  308. — Head  and  mouth- 
parts,  much  enlarged,  of 
thrips.  ant.,  antenna;  lb., 
labrum;  tnd.,  mandible;  7nx., 
maxilla;  mx.p.,  maxillary  pal- 
pus; li.p.,  labial  palpus;  m.s., 
mouth-stylet,  (After  Uzel; 
much  enlarged.) 


Bugs,  Cicadas,  Aphids,  and  Scale-insects         221 

to  be  expanded  by  becoming  suddenly  filled  with  blood,  and  contracted 
l)y  a  receding  of  the  blood. 

The  eggs  are  laid  either  under  bark  or  on  the  surface  of  leaves  or,  in 
the  case  of  certain  species  which  have  a  sharp  little  ovipositor,  underneath 
the  leaf-epidermis.  They  hatch  in  from  three  to  fifteen  days,  varying  with  the 
different  species  observed,  and  the  young  grow  and  feed  for  from  five  to 
forty  days.  Then  follows  the  brief,  quiet,  non-feeding  stage,  and  the  insect 
becomes  mature.  Probably  several  generations  appear  in  a  year.  The 
winter  is  passed  in  either  larval,  pupal,  or  adult  stage,  under  bark,  in  dry, 
hollow  plant-stems,  in  lichens  or  moss,  or  on  the  ground  under  fallen  leaves. 
A  curious  variation  in  the  adults  of  many  species  has  been  noted  in  reference 
to  the  wings;  adult  individuals  of  a  single  species  may  have  either  fully 
developed  wings,  very  short  functionless  wings,  or  even  none  at  all;  both 
sexes  may  be  winged,  or  one  winged  and  the  other  not;  one  or  both  sexes 
may  be  short-winged  or  both  be  wingless.  There  seems  to  exist  a  condi- 
tion somewhat  like  that  in  the  plant-lice  (Aphidida;) ,  wings  being  developed 
in  accordance  with  special  needs  or  influences,  as  scarcity  of  food,  time  of 
the  year,  etc. 

Another  peculiarity  of  the  adults  is  the  rarity,  and  even,  apparently, 
the  total  lack  of  males  in  some  species.  Parthenogenetic  development  (the 
production  of  young  from  unfertilized  eggs)  is  very  common  throughout 
the  order. 

While  the  food  of  those  thrips  most  easily  found  by  the  beginning  student 
is  the  sap  taken  from  flower  parts,  most  of  the  sap-drinking  species  get  their 
supply  from  the  leaves  of  various  plants,  and  when  these  plants  happen  to 
be  cultivated  ones  of  field  or  garden,  and  the  thrips  are  abundant,  these 
tiny  insects  get  the  ugly  name  of  "pests."  Three  species  in  particular  are 
recognized  by  economic  entomologists  as  pests,  viz.,  the  onion-thrips 
{Thrips  tabaci),  the  wheat-thrips  (Eiilhrips  tritici),  and  the  grass-thrips 
(Anaphothrips  striatus).  The  first  of  these  is  about  ^j  inch  long,  about 
one-fourth  as  wide  as  long,  and  of  a  uniformly  light-yellowish  to  brownish- 
yellow  color.  It  feeds  on  many  different  cultivated  plants,  as  apple,  aster, 
blue  grass,  melons,  clover,  tobacco,  tomato,  cauliflower,  etc.,  etc.,  but  its 
chief  injuries  seem  to  be  to  onions  and  cabbages.  It  occurs  all  over  Europe, 
England,  and  the  United  States,  and  is  probably  the  most  injurious  species 
in  the  order.  The  wheat-thrips,  also  but  -^^  inch  long,  brownish  yellow 
with  orange-tinged  thorax,  attacks  many  plants  besides  wheat,  and  is  very 
fond  of  puncturing  the  pistils  and  stamens  of  strawberry-flowers,  thus  often 
preventing  fertilization  and  consequent  development  of  fruit.  The  life- 
cycle  of  this  species  is  very  short,  requiring  only  twelve  days.  Eggs  depos- 
ited in  the  tissues  of  infested  plants  hatch  in  three  days,  the  larvae  are  full- 


222         Bugs,  Cicadas,  Aphids,  and  Scale-insects 

grown  in  five  days,  and  the  quiescent  pseudo-pupal  stage  lasts  icur  days. 
The  grass-thrips  is  the  cause  of  the  injury  or  disease  of  meadow  and  pasture 
grasses  known  as  "silver  top"  or  "white  top,"  a  common  trouble  in  the 
northeastern  states.  The  male  sex  seems  to  be  wanting  in  this  species,  the 
young  all  developing  parthenogenetically. 


CHAPTER  XI 


THE    NERVE -WINGED    INSECTS 

(Order  Neuroptera)  SCORPION-FLIES 
(Order  Mecoptera),  AND  CADDIS- 
FLIES  (Order  Trichoptera). 

INN.'EUS,  the  first  great  classifier  of  animals  and 
plants,  found  in  the  character  of  the  wings  a 
simple  basis  for  grouping  insects  into  orders. 
For  the  wingless  insects  he  established  the  order 
Aptera ;  *  the  two-winged  ones  he  called  Diptera ; 
the  moths  and  butterflies,  with  scale-covered 
wings,  he  called  Lepidoptera;  the  beetles  with  their  horny  sheath-like  fore 
wings  he  termed  Coleoptera;  the  thin-  and  membranous-winged  ants,  bees, 
wasps,  and  ichneumon-flies  he  named  Hymenoptera;  to  the  roaches,  crickets, 
locusts,  and  katydids,  with  their  parchment-like  straight-margined  fore  wings,' 
he  gave  the  name  Orthoptera;  the  sucking-bugs  with  their  fore  wings 
having  the  basal  half  thickened  and  veinless,  the  apical  half  membranous 
and  veined,  he  called  Hemiptera;  and  finally  he  grouped  the  heterogeneous 
host  of  dragon-flies,  May-flies,  ant-lions,  lace-winged  flies  et  al.,  with  their 
thin  netted-  or  nerve-veined  wings,  in  the  order  Neuroptera. 

In  the  light  of  our  present  greatly  increased  knowledge  of  the  structure 
and  development  (the  two  bases  of  classification)  of  insects,  this  primary 
Linnaean  arrangement  can  no  longer  be  accepted  as  an  exposition  of  the 
true  relationships  among  the  larger  groups  of  insects;  that  is,  it  is  obviously 
not  a  natural  classification.  Its  greatest  faults  are  that  it  groups  together 
in  the  Aptera  degenerate  wingless  members  of  various  unrelated  groups  with 
the  true  primitively  wingless  insects,  and  places  together  in  the  Neuroptera 
a  host  of  insects  of  somewhat  similar  superficial  appearance,  but  of  radically 
dissimilar  fundamental  structure  and  development.  With  increasing  knowl- 
edge of  the  characteristics  of  the  various  subgroups  in  the  Linnaean  order 
Neuroptera,  the  too  aberrant  ones  have  been  gradually  one  by  one  removed, 

*  Aptera,  from  a,  without,  pteron,  a  wing;  Diptera,  from  dis,  double,  pteron,  a  wing; 
Lepidoptera,  from  lepis,  a  scale,  pteron,  a  wing;  Coleoptera,  from  koleos,  a  sheath,  pteron, 
a  wing;  Hymenoptera,  from  Intmen,  a  membrane,  pteron,  awing;  Orthoptera,  from  orthos, 
straight,  pteron,  a  wing;  Hemiptera,  from  hemi,  half,  pteron,  a  wing;  Neuroptera,  from 
neuron,  a  nerve,  pteron,  a  wing. 


2  24    Nerve-winged  Insects;   Scorpion-flies;    Caddis-flies 

and  in  most  cases  given  specific  ordinal  rank.  Thus  we  now  consider  the 
May-flies  to  from  an  order,  the  stone-flies  another,  the  dragon-flies  still 
another,  and  so  on.  There  are  left,  grouped  together  as  the  order  Neu- 
roptera,  seven  families  which  possess  the  common  characteristics  of  netted- 
veined  wings  (numerous  longitudinal  and  cross  veins),  mouths  with  well- 
developed  biting  or  piercing  jaws  (mandibles),  and  a  development  with  com- 
plete metamorphosis.  Further  than  this  little  can  be  said  to  characterize 
the  order  as  a  whole,  and  we  may  proceed  at  once  to  a  consideration  of  the 
various  distinct  families. 

KEY  TO  THE  FAMILIES  OF  NEUROPTERA. 

A.      Prothorax  as  long  as  or  longer  than  the  mesothorax  and  the  metathorax  combined. 

B.      Fore  legs  greatly  enlarged  and  fitted  for  grasping Mantispid^. 

BB.  Fore  legs  not  enlarged  and  not  fitted  for  grasping Raphidiid^. 

AA.  Prothorax  not  as  long  as  the  mesothorax  and  the  metathorax  combined. 

B.      Hind  wings  broad  at  the  base,  and  with  that  part  nearest  the  abdomen  (the 

anal  area)  folded  like  a  fan  when  not  in  use Sialid^. 

BB.  Hind  wings  narrow  at  base,  and  not  folded  like  a  fan  when  closed. 
C.      Wings  with  very  few  veins,   and  covered  with  whitish  powder. 

CONIOPTERYGIDvE. 

CC.  Wings  with  numerous  veins,  and  not  covered  with  powder. 

D.       Antennae  gradually  enlarged  towards  the  end,   or  filiform  with  a 

terminal  knob Myrmeleonid^. 

DD.  Antennse   without   terminal  enlargement. 

E.      Some  of  the  transverse  veins  between  the  costa  and  subcosta 
forked  (in  all  common  forms),  wings  brownish  or  smoky. 

Hemerobhd^. 

EE.  Transverse    veins    between    the    costa    and    subcosta    simple, 

wings  greenish Chrysopid^. 

While  most  of  the  Neuroptera  are  terrestrial  in  both  immature  and  adult 
life,  one  family,  the  Sialidse,  includes  forms  whose  larvae  are  aquatic.  There 
are  only  three  genera  in  the  family,  but  all  are  fairly  familiar  insects  to  col- 
lectors and  field  students.  The  adults  of  these  genera  can  be  distinguished 
by  the  following  key: 

Fourth  segment  of  the  tarsus  bilobed;   no  simple  eyes  (ocelli) Sialis. 

Fourth  segment  of  the  tarsus  simple,  cylindrical;    three  simple  eyes  (ocelli). 

Antennje  with  segments  enlarged  at  the  outer  ends;   hind  corners  of  the  head. rounded. 

Chauliodes. 

Antennae  with  segments  cylindrical;    hind  corners  of  the  head  with  a  sharp  angulation 

or  tooth CORYDALIS. 

The  larvs  can  be  distinguished  by  the  following  key: 
Tip  of  abdomen  bearing  a  single  long,  median,  laterally  fringed  tail-like  process.  .Si.^Lis. 
Tip  of  abdomen  forked,  the  two  fleshy  projections  each  bearing  a  pair  of  hooks. 

Lateral  filaments  (soft,  slender,  tapering  processes  projecting  from  the  sides  of  the  abdom- 
inal segments)  with  no  tuft  of  short  hair-like  tracheal  gills  at  base. .  .Chauliodes. 
Lateral  filaments  each  with  a  tuft  of  short,  hair-like,  tracheal  gills  at  base.  .Corydalis. 


Nerve- winged  Insects;   Scorpion-flies;    Caddis-flies    225 


Two  species  of  Sialis  occur  in  this  country;  they  are  called  alder-flies, 
or  orl-flies.  The  smoky  orl-fly,  Sialis  infitmata,  widely  distributed  over 
this  country,  is  a  dusky  brownish  in- 
sect about  ^  inch  long,  often  seen,  with 
wings  closely  folded,  sitting  on  sedge- 
leaves  near  quiet  waters.  The  larvae 
(Fig.  309),  according  to  Needham,  live 
in  marshy  places  tilled  with  aquatic 
plants,  on  the  borders  of  streams  and 
ponds.  When  full  grown  they  are 
about  an  inch  long,  and  keep  up  an 
undulating  motion  with  the  abdomen, 
the  long  tail  being  intermittently  lashed 
up  and  down.  When  full  grown  the 
larva  crawls  out  of  the  water   and  at    Fig.  309. — Larva  (at  right)  and  pupa  (at 

some  little  distance  burrows  into  the       Y!^}    °L  ^"    ""^"^y- .  ■^''^^"    in/umata. 

.  (Alter  JNeedham;    twice  natural  size.) 

moist  soil  for  a  few  inches  or  even  a 

foot  or  more.      Here  it  forms  an  oval  cell  and  pupates  within  it.     Two  or 

three  weeks  after  the  adult  fly  issues. 

Of  Chauliodes,  the  fish-flies  (Fig.  310),  eight  North  American  species 

are  known.     The  adults  are  from    i^  to   2^  inches  long,  and  their  wings 

expand  from  2^  to  4  inches.     The  wings  are  grayish  or  brownish  with  whitish 

spots  or  bands,  and  the  antennae  are  curiously  feathered  or  pectinate.     The 


Fig.  310. — The  saw-horned  fish-fly,  Chauliodes  serricornis,  laying  eggs. 
(After  a  photograph  from  life  by  Needham;    natural  size.) 


larvae  live  in  wet  places  at  the  edge  of  water  or  in  water  close  to  the  surface. 
According  to  Needham  they  are  perhaps  oftenest  found  clinging  to  the  under 
side  of  floating  longs  or  crawling  beneath  the  loosened  bark.  They  are 
predaceous,  feeding  upon  other  aquatic  insects.  When  ready  to  transform 
they  excavate  a  cell  above  the  level  of  the  water  under  a  stone  or  log  or  layer 


226    Nerve-winged  Insects ;   Scorpion-flies;    Caddis-flies 

of  moss  or  in  a  rotten  log,  in  which  they  pupate,  and  from  which  the  adult 

fly  issues  in  about  two  weeks. 

The  genus  Corydalis  (Fig.  311)  is  represented  by  a  single  species,  C.  corniita, 

but  it  is  such  a  conspicuous  and  wide-spread  insect  that  it  is  probably  the 

best-known  species  in  the  whole  order 
Neuroptera.  The  adult  fly  is  most  com- 
monly called  "hellgrammite,"  while  the 
larvae  (Fig.  312),  much  used  by  fisher- 
men as  bait,  are  known  as  dobsons  or 
crawlers.  But  other  names  are  often 
used.  Howard  lists  the  following  array 
of  names,  collected  by  Professor  W.  W. 
Bailey,  which  are  applied  to  the  larva 
in  Rhode  Island  alone:  dobson,  crawler, 
arnly,  conniption-bug,  clipper,  water- 
grampus,  gogglegoy,  bogart,  crock,  hell- 
devil,  flipflap,  alligator,  Ho  Jack,  snake- 


FiG.  311. 


Fig.  312. 


Fig.   311. — Dobson-fly,  Corydalis  corniita,  male,  with  head  of  female  above.     (Natural 

size.) 
Fig.   312. — Larva  of  dobson-fly,   Corydalis  corniita.     (Natural  size.) 


doctor,  dragon,  and  hell-diver.  The  insect  is  very  common  about  Ithaca, 
N.  Y.,  and  Professor  Comstock  of  Cornell  University  gives  the  following 
account  of  its  life-history  as  observed  by  him  there:  "  The  larvae  live  under 
stones  in  the  beds  of  streams.     They  are  most  abundant  where  the  water 


Nerve- winged  Insects ;   Scorpion-liies ;    Caddis-flies    227 


flows  swiftest.     They  are  carnivorous,  feeding  upon  the  nymphs  of  stone- 
flies,  May-flies,  and  other  insects.     When  about  two  years  and  eleven  months 


fbnd        „^„ 

I  ant  frf\-~^\  i    ,f\^^y\^  p.an(. 


Intjr 


Ih'W 


Fig.  313. — Head  of  larva,  pupa,  and  adult  of  dobson-fly,  Corydalis  cornuta,  showing 
development  of  the  mouth-parts  of  the  adult  within  the  mouth-parts  of  the  larva. 
A,  head  of  a  larva  with  its  cuticle  dissected  away  on  the  right-hand  side,  revealing 
the  pupal  parts;  B,  head  of  male  pupa  with  cuticle  dissected  away  on  right-hand 
side,  revealing  developing  imaginal  parts;  C,  head  of  female  pupa  with  cuticle 
wholly  removed,  showing  imaginal  parts;  D,  head  of  adult  male,  md.,  mandible; 
mx.,  maxilla;  H.,  labium;  lb.,  labrum;  ant.,  antenna;  l.h.,  larval  head-wall;  p.h., 
pupal  head-wall;  ga.,  galea;  li.p.,  labial  palpus;  mx.p.,  maxillary  palpus.  Any 
of  these  terms  may  be  prefixed  by/,  larva;  p,  pupa;  or  i,  imago. 

old  the  larva  leaves  the  water,  and  makes  a  cell  under  a  stone  or  some  other 
object  on  or  near,  the  bank  of  the  stream.     This  occurs  during  the  early 


22  8    Nerve-winged  Insects;   Scorpion-flies;    Caddis-flies 


part  of  the  summer;  here  the  larva  changes  to  a  pupa.  In  about  a  month 
after  the  larva  leaves  the  water  the  adult  Insect  appears.  The  eggs  are 
then  soon  laid;  these  are  attached  to  stones  or  other  objects  overhanging 
the  water.  They  are  laid  in  blotch-like  masses  which  are  chalky-white 
in  color  and  measure  from  half  an  inch  to  nearly  an  inch  in  diameter.  A 
single  mass  contains  from  two  thousand  to  three  thousand  eggs.  When 
the  larvae  hatch  they  at  once  find  their  way  into  the  water,  where  they 
remain  until  full-grown." 

In  the  Kansas  corn-fields  I  used  to  find  certain  wonderfully  beautiful, 
frail,  gauzy-winged  insects  resting  or  walking  slowly  about  on  the  great 
smooth  green  leaves.  The  eyes  of  these  insects  shone  like  burnished  copper 
or  shining  gold,  and  this  with  the  fresh  clear  green  (tinged  sometimes  with 
bluish,  sometimes  with  yellowish)  of  the  lace-like  wings  and  soft  body  made 
me  think  them  the  most  beautiful  of  all  the  insects  I  could  find.  But  a 
nearer  acquaintanceship  was  always  unpleasant;  when  "collected"  they 
emitted  such  a  disagreeable  odor  that  admiration  changed  to  disgust.  These 
lace-winged  or  golden-eyed  flies  are  common  all  over  the  country  and  com- 
pose a  family  of  Neuroptera 
called  ChrysopidcC.  All  except 
two  species  of  the  family  belong 
to  the  single  genus  Chrysopa, 
which  includes  more  than  thirty 
species  found  in  the  United 
States.  In  the  Chrysopida;  the 
larvae  are  not  aquatic  as  in  the 
family  Siahdae,  but  are  active 
and  fiercely  predaceous  little 
creatures  called  aphis-lions,  that 
crawl  about  over  herbage  and 
shrubbery  in  search  of  living 
aphids  (plant-lice)  and  other 
small  soft-bodied  insects.  The 
aphis-lion  (Fig.  314)  has  a  pair 
Fig.  314.— The  golden-eyed  or   lace-winged  fly,       .    ,  shirn-T^ointed      slender 

Chrysopa  sp.;  adult,  eggs,  larva,  "aphis-lion,"  ^i  long,^  snarp  pomtea,  sienoer 
and  pupal  cocoons  on  the  under  side  of  leaf,  jaws  which  are  grooved  on  the 
(Natural  size.)  -^^^^^    f^^g_       Having    found    a 

plant-louse  it  pierces  its  body  with  the  sharp  jaw-points,  and  holds  it  up,  so 
that  the  'blood  of  its  victim  runs  along  these  grooves  into  its  thirsty  throat. 
The  Chrysopa  larvae  will  bravely  attack  insects  larger  than  themselves,  or  will 
quite  as  readily  prey  on  the  defenceless  eggs  of  neighbor  insects,  or  indeed  of 
their  own  kind.  Indeed,  probably  because  of  this  egg-sucking  habit  the  female 
lace-winged  fly  deposits  her  eggs  each  on  the  tip  of  a  tiny  slender  stem,  about 


Nerve- winged  Insects;   Scorpion-Hies;    Caddis-flies    229 

half  an  inch  high,  fastened  at  the  base  to  a  leaf  or  twig  (Fig.  314).  When 
the  first  larvae  hatch  they  crawl  down  the  stems  and  wander  around  in  this 
little  forest  of  egg-trees,  but  fortunately  haven't  wit  enough  to  crawl  up  to 
the  still  unhatched  eggs  of  their  brothers  and  sisters.  When  the  aphis-lion 
is  full-fed  and  grown,  which,  in  the  studied  species,  occurs  in  from  ten  days 
to  two  weeks,  it  crawls  into  some  sheltered  place,  as  in  a  curled  leaf  or 
crevice  in  the  plant-stem,  and  spins  a  small,  spherical,  glistening,  white, 
silken  cocoon,  within  which  it  pupates.  In  another  ten  days  or  two  weeks 
the  delicate  lace-winged  golden-eyed  green  imago  bites  its  way  out,  cutting 
out  a  neat  circular  piece. 

In  the  family  Hemerobiidas  are  some  insects  whose  larvae  are  also  called 
aphis-lions;  these  belong  to  the  typical  genus  Hemerobius.  But  in  two 
rare  genera  of  the  family,  Sisyra  (Fig.  315)  and  Climacia,  the  immature 
stages  are  aquatic,  the  small  larvae  (about  i  inch  long)  living  as  parasites 


Fig.  316. 


Fig.  3156. 


Fig.  315c. 


Fig.  317. 


Fig.  315. — Sisyra  umhrata.    a,  adult;  ft,  larva;  c,  pupa.    (All  about  five  times  natural  size.) 
Fig.  316. — Polystwchotes  punctatits.     (Natural  size.) 
Fig.  317. — Hemerobius  sp.     (Three  times  natural  size.) 

on  or  in  fresh-water  sponges  (Spongilla).  The  largest  members  of  the 
family  belong  to  the  genus  Polystoechotes,  of  which  two  species  are  known. 
The  commoner  one,  P.  punctatus  (Fig.  316),  is  about  i\  inches  long  and  its 
wings  expand  2  to  3  inches.     It  is  nocturnal  and  is  to  be  collected  about 


230    Nerve-winged  Insects;   Scorpion-flies;    Caddis-flies 

lights.  Its  body  is  blackish,  and  the  wings  are  clear  but  mottled  with  irreg- 
ular brownish-black  spots.  When  at  rest  the  wings  are  held  steeply  roof- 
like over  the  back.  Nothing  is  known  of  its  life-history.  Of  the  best-known 
genus,  Hemerobius  (Fig.  317),  twenty  species  have  been  noted  in  this  country, 
but  they  are  small,  dull-colored  insects,  and  are  rather  rare,  or  at  least 
infrequently  seen.  Comstock  says  they  occur  in  forests  and  especially  on 
coniferous  trees.  The  larvae  are  like  the  Chrysopa  larvae,  predaceous  and 
well  equipped  with  big  strong  head  and  sharp,  curved  seizing  and  blood- 
sucking mouth-parts.  The  larvae  (Fig.  318)  of  some  species  have  the 
curious  habit  of  piling  up  on  their  back  the  empty,  shriveled  skins  of  their 
victims,  until  the  aphis-lion  is  itself  almost  wholly  concealed  by  this  unlovely 
load  of  rehcts.  This  is  true  of  all  the  Hemerobius  larvae  I  have  seen  in 
California.  Stripped  of  the  covering  of  skins  the  aphis-lion  is  seen  to  have 
a  short,  broad,  flattened  body,  with  numerous  long,  spiny  hairs  arising  from 
tubercles.     These  hairs  help  to  hold  the  mass  of  insect  skins  together. 

Still  other  Neuroptera  with  fierce,  ever-hungry,   carnivorous  larvae  are 
the  ant-lions,  or  Myrmeleonidae.     The  horrible  pit  of  Kipling's  story,  into 


Fig.  318. 


Fig.  319. 


Fig   320. 


Fig.  318. — Larva  of  Hemerobius  sp.  covered  with  detritus.     (From  life;  four  times  natural 

size.) 
Fig.  319. — Larva  of  ant-lion,  Myrmeleon  sp.     (Three  times  natural  size.) 
Fig.  320. — Pit  of  ant-lion  and,   in  lower  right-hand  corner,   pupal  sand-cocoon,   from 

which  adult  has  issued,  of  ant-lion,  Myrmeleon  sp.     (About  natural  size.) 


which  Morrowbie  Jukes  rode  one  night,  is  paralleled  in  fact  in  that  lesser 
world  of  insect  life  under  our  feet.  The  foraging  ant,  too  intent  on  bringing 
home  a  rich  spoil  for  the  hungry  workers  in  the  crowded  nest  to  watch  care- 
fully for  dangers  in  its  path,  finds  itself  without  warning  on  the  crumbling 


Nerve-winged  Insects;   Scorpion-tiies ;    Caddis-flies    231 

verge  of  a  deep  pit  (Fig.  320).  The  loose  sand  of  the  pit's  edge  slips  in  and 
down,  and  the  frantic  struggles  of  the  unlucky  forager  only  accelerate  the 
tiny  avalanche  of  loose  soil  and  sand  that  carries  it  down  the  treacherous 
slope.  Projecting  from  the  very  bottom  of  the  pit  is  a  pair  of  long,  sickle- 
like, sharp-pointed  jaws,  adapted  most  effectively  for  the  swift  and  sure 
grasping  and  piercing  and  blood-letting  of  the  trapped  victims.  The  body 
of  the  ant-lion  (Fig.  319)  is  almost  wholly  concealed  underneath  the  sand; 
only  the  vicious  head  and  jaws  protrude  above  the  surface  in  the  pit's  depths. 
Comstock  has  seen  the  ant-lion  throw  sand  up  from  the  bottom,  using  its 
flat  head  like  a  shovel  in  such  a  way  that  the  flung  sand  in  falling  would 
strike  an  ant  slipping  on  the  slope  and  tend  to  knock  it  down  the  side.  Ant- 
lion  pits  are  to  be  found  all  over  the  country,  in  warm,  dry,  sandy  places. 
The  ant-hons  can  be  brought  home  alive,  and  kept  in  a  dish  of  sand,  where 
their  habits  may  be  observed. 

The  adult  ant-lion  (Fig.  321)  is  a  rather  large,  slender-bodied  insect 
with  four  long  oar-shaped  gauzy  wings,  thickly  cross-veined  and  usually 
more  or  less  spotted  with  brownish  or  black.     The  eggs  are  laid  in  the  sand 


Fig.    321. — Adult   ant-lion,  Myrmeleon.     (Natural   size.) 

and  the  freshly-hatched  larvae  or  ant-lions  immediately  dig  little  pits.  When 
the  larvae  are  full-grown — and  just  how  long  this  takes  is  not  accurately 
known — each  forms  a  curious  protecting  hollow  ball  of  sand  held  together 
by  silken  threads,  lines  it  inside  smoothly  with  silk,  and  pupates  in  this  cozy 
and  safe  nest  (Fig.  320).  The  larva  is  said  to  lie  for  some  time,  even  through 
a  whole  winter,  in  this  cocoon  before  pupating.  The  life-history  of  no  ant- 
lion  species  is  yet  thoroughly  known. 

The  family  Myrmeleonidae  includes  eight  genera,  which  are  usually 
grouped  into  two   subfamihes  as  follows: 

Antennae  nearly  as  long  as  wings Ascalaphin^. 

Antennae  not  one-third  as  long  as  wings Myrmeleonin^. 

The  subfamily  Myrmeleoninae  includes  the  true  ant-lions  with  habits 
in  general  as  already  described.  The  live  genera  in  it  may  be  distinguished 
by  the  following  key: 


232    Nerve-winged  Insects ;   Scorpion-flies;    Caddis-flies 

Claws  very  stout,  swollen Acanthaclisis. 

Claws  slender  at  base,  not  swollen. 

Wings  with  a  black  band  at  tip  or  eye-like  spots Dendroleon. 

Wings  not  as  above. 

Tibia  with  no  spurs  (short  but  conspicuous  spines) Maracanda. 

Tibia  with  spurs. 

Wings  with  a  single  row  of  costal  areoles  (small  cells) Myrmeleon. 

Wings  with  a  double  row  of  costal  areoles Brachynemurus. 

The  subfamily  Ascalaphinse  includes  but  three  genera  and  six  species, 
the  larvae  of  which  do  not  dig  pits  (as  far  as  known),  but  hide  under  stones 
sometimes  with  the  body  partially  covered  with  sand,  or  even  nearly  buried 
in  it,  and  wait  for  prey  to  come  within  reach  of  their  long,  sickle-like  jaws. 
The  adults  of  this  subfamily  can  be  readily  recognized  by  their  long  antennae, 
knobbed  at  the  tip,  like  the  antennae  of  butterflies.  The  habits  and  life- 
history  of  Ulula  hyalina,  an  Ascalaphid  found  in  the  southern  states,  have 
recently  been  studied  by  McClendon  in  Texas.  The  adult  fly  when  at 
rest  clings,  motionless,  to  some  small  branch  or  stalk,  head  down  with  wings 
and  antennae  closely  applied  to  the  branch,  and  abdomen  erected  and  often 
bent  so  as  to  resemble  a  short  brown  twig  or  dried  branch  (Fig.  322).     The 


Fig.  322.  Fig.  323. 

Fig.  322. — An  Ascalaphid,  Ulula  hyalina,  male.  (After  McClendon;  natural  size.) 
Fig.    323. — Larva  of  Ulula  hyalina.     (After  McClendon;    natural  size,  ^  inch.) 

eggs  are  arranged  in  two  rows  along  a  stalk  and  fenced  in  below  by  little 
rod-like  bodies  called  repagula,  placed  in  circles  around  the  stalk.  The 
eggs  hatch  in  nine  or  ten  days,  and  the  larvae  (Fig.  323)  crawl  down,  after  a 
day  of  resting,  and  hide  under  stones  or  in  slight  depressions.  The  body 
is  covered  with  sand  and  the  jaws  open  widely.  When  a  small  insect  crawls 
within  reach  the  jaws  snap  together,  pinioning  the  victim  on  the  curved 
points.  The  jaws  are  grooved  along  the  inner  or  lower  side  and  the  maxillae 
fit  into  these  grooves  so  as  to  form  a  pair  of  ducts  or  channels  through  which 
the  blood  is  sucked  into  the  mouth.     The  larva  often  changes  its  hiding-place 


Nerve-winged  Insects;   Scorpion-flies;    Caddis-flies     233 

at  night.     It  lives  about  sixty  days,  and  then  seeks  a  concealed  place  and 
forms  a  spherical  cocoon  of  sand  and,  silk  within  which  it  pupates. 

Our  three  genera  of  the  Ascalaphinae  may  be  determined  by  the  follow- 
ing key: 

Eyes   entire Ptynx. 

Eyes  grooved. 

Hind  margin  of  wings  entire Ului.a. 

Hind  margin  of  wings  excised Colobopterus. 

Under  the  loose  hanging  strips  of  bark  on  the  eucalyptus-trees  in  Cali- 
fornia or  on  the  bark  of  various  Pacific  Coast  conifers,  as  pine,  spruce,  and 
cedar,  one  may  often  find  certain  odd,  slender-necked,  big-headed,  gauzv- 
winged,  blackish  insects  about  half  an  inch  long  (Fig.  324).  A  slangy  student 
once  proposed  the  name  "rubber-neck"  for  them,  and  it  is  a  fairly  fit  one. 
These  "rubber-necks,"  or  "snake-flies,"  belong  to  the  family  Raphidiida;, 
of  which  but  two  genera  are  known  in  the  world.  The  species  of  the  genus 
Raphidia  have  three  simple  eyes  (ocelli),  while  those  of  Inocellia  have  no 
oceUi.      Twenty-four   species  are  found   scattered  over   Asia  Minor,  Syria, 


^^ 


Fig.  324. — Raphidia  sp.,  aduh,  larva,  and  pupa.     (Two  and  a  half  times  natural  size.) 


eastern  Siberia,  Europe,  and  England,  while  four  species  of  Raphidia  and 
three  of  Inocellia  occur  in  the  western  half  of  the  United  States.  The 
snake-flies  are  predaceous  insects,  the  larvae  being  notoriously  voracious 
insectivores.  The  larvae  live  in  crevices  of  bark,  or  under  it,  where 
there  are  breaks  in  it,  as  is  always  the  case  on  old  trees  of  most  eucalyptus 
species. 

Snake-fly  larvae  are  said  to  find  and  eat  many  larvae  of  the  codlin-moth, 
one  of  the  worst  pests  of  apple-trees.  Many  of  the  codlin-moth  larvae  crawl 
into  crevices  in  the  apple-tree  bark  to  spin  their  cocoon,  and  there  meet 
the  hungry  snake-fly  larvae. 

The  pupae  (Fig.  324),  which  are  not  enclosed  in  silken  cocoons  like  the 
other  terrestrial  Neuroptera  (ant-Uons,  lace-winged  flies,  Hemerobians),  lie 


2  34    Nerve- winged  Insects;   Scorpion-flies;    Caddis-flies 

concealed  in  sheltered  places.  They  are  active,  though,  when  disturbed,  and 
look  much  like  the  larvae,  but  are  more  robust-bodied  and  bear  externally 
the  developing  wings.  The  head,  with  eyes  and  antennae,  is  more  like  that 
of  the  adult.  The  complete  metamorphosis  of  these  insects  seems  very 
simple  compared  with  that  of  such  other  holometabolous  insects  as  house- 
flies  and  honey-bees.  The  adult  female  (Fig.  324)  has  a  long,  slender, 
curved,  pointed  ovipositor,  which  probably  is  used  to  deposit  the  eggs  in 
deep,  narrow,  and  safe  cracks  in  the  bark.  But  the  oviposition  has  not 
yet  been  seen,  and  the  full  life-history  of  the  Raphidians  has  yet  to  be  worked 
out. 

The  extraordinary-looking  insect  shown  in  Fig.  325  is  one  of  the  few 
members  of  the  Mantispidae,  the  sixth  family  of  the  Neuroptera.  Its  great 
spiny,  grasping  fore  legs  and  its  long  neck  make  it  resemble  its  namesake, 
the  praying-mantis  of  the  order  Orthoptera,  but  its  four  membranous,  net- 
veined  wings  show  its  affinities  with  the  Neuroptera.  The  fore  legs  are  like 
those  of  the  mantis  because  Mandspa  has  similar  habits  of  catching  hve 
prey  with  them:  it  is  a  case  of  what  is  called  by  biologists  "parallehsm  of 
structure,"  by  which  is  meant  that  certain  parts  of  two  animals  become 
developed  or  specialized  along  similar  lines,  not  because  of  a  near  relation- 
ship between  them,  but  because  of  the 
adoption  of  similar  habits.  The  wings  of 
bats  and  those  of  birds  show  a  general 
parallelism  of  structure,  although  bats  and 
.  birds  belong  to  two  distinct  great  groups 
of  animals. 

Only  two   genera,  viz.,  Mantispa    and 
Symphasis,  of  Mantispidae  are  known,  and 

^  ^       ,     .     .  ,„        these    include  but  five  American    species. 

Fig.  325. — Symphasts  stgnata.   (One  .        .  .  \    •      r         j    • 

and  one-half  times  natural  size.)         Symphasts  signata   (Fig.  325)   IS  found  m 

California,  while  of  the  four  species  of  Man- 
tispa three  are  found  in  the  East  and  South,  while  one  ranges  clear  across  the 
continent.  But  they  are  insects  only  infrequently  seen,  and  each  captured 
specimen  is  a  prize.  The  life-history  of  no  one  of  our  species  has  been  studied — 
an  opportunity  for  some  amateur  to  make  interesting  and  needed  observations 
— but  Brauer  has  traced  the  life  of  the  European  species,  Mantispa  styriaca, 
and  found  it  of  unusual  and  extremely  interesting  character.  The  following 
account  of  Brauer's  observations  is  quoted  from.  Sharp  (Cambridge  Natural 
History,  vol.  v):  "The  eggs  are  numerous  but  very  small,  and  are  deposited 
in  such  a  manner  that  each  is  borne  by  a  long  slender  stalk,  as  in  the  lace- 
wing  flies.  The  larvae  are  hatched  in  autumn;  they  then  hibernate  and 
go  for  about  seven  months  before  they  take  any  food.  In  the  spring,  when 
the  spiders  of  the  genus  Lycosa  have  formed  their  bags  of  eggs,  the  minute 


Nerve- winged  Insects;   Scorpion-flies;   Caddis-flies    235 

Mantispa  Iarva3  find  them  out,  tear  a  hole  in  the  bag,  and  enter  among  the 
eggs;  here  they  wait  until  the  eggs  have  attained  a  fitting  stage  of  develop- 
ment before  they  commence  to  feed.  Brauer  found  that  they  ate  the  spiders 
when  these  were  quite  young,  and  then  changed  their  skin  for  the  second 
time,  the  first  moult  having  taken  place  when  they  were  hatched  from  the 
egg.  At  this  second  moult  the  larva  undergoes  a  considerable  change  of 
form;  it  becomes  unfit  for  locomotion,  and  the  head  loses  the  compara- 
tively large  size  and  high  development  it  previously  possessed.  The 
Mantispa  larva — only  one  of  which  flourishes  in  one  egg-bag  of  a  spider — • 
undergoes  this  change  in  the  midst  of  a  mass  of  dead  young  spiders  it  has 
gathered  together  in  a  peculiar  manner.  It  undergoes  no  further  change 
of  skin,  and  is  full-fed  in  a  few  days;  after  which  it  spins  a  cocoon  in  the 
interior  of  the  egg-bag  of  the  spider,  and  changes  to  a  nymph  inside  its  larva- 
skin.  Finally  the  nymph  breaks  through  the  barriers — larva-skin,  cocoon, 
and  egg-bag  of  the  spider — by  which  it  is  enclosed,  and  after  creeping  about 
for  a  little  appears  in  its  final  form  as  a  perfect  Mantispa." 

Thus  in  this  insect  the  larval  life  consists  of  two  different  stages,  one 
of  which  is  specially  adapted  for  obtaining  access  to  the  creature  it  is  to 
prey  on. 

The  ConiopterygidcT  include  a  few  tiny,  obscure  insects,  the  smallest 
members  of  the  order.  They  have  wings  with  very  few  cross-veins,  and 
both  wings  and  body  are  covered  with  a  fine  whitish  powder,  hence  the  name 
"dusty  wings"  which  entomologists  apply  to  them.  Only  two  species  are 
known  in  this  country,  of  neither  of  which  is  the  life-history  known.  In 
Europe  the  larvae  of  a  "dusty  wing"  species  have  been  found  feeding  on 
scale-insects.  When  full-fed  these  larvae  spin  a  silken  cocoon,  within  which 
they  transform. 

The  small  and  little-known  order  Mecoptera  includes  certain  strange 
little  wingless,  shining  black,  leaping  insects  found  on  snow,  some  larger 
net-veined-winged  insects  with  the  abdomen  of  the  males  ending  in  a  swollen 
curved  tip  bearing  a  projecting  clasping-organ  resembling  slightly  a  scor- 
pion's sting  in  miniature,  and  a  number  of  still  larger,  slender-bodied,  narrow- 
winged  insects.  The  only  popular  name  possessed  by  any  of  these  insects 
is  that  of  scorpion-flies,  which  has  been  given  the  few  species  with  pseudo- 
stings.  For  these  scorpion-flies  are  not  stinging-insects,  although  the  males 
can  pinch  hard  with  the  caudal  clasping-organ.  But  little  is  known  of  the 
life-history  of  any  members  of  the  order,  nor  is  much  known  of  the  habits 
of  the  imagoes. 

There  are  but  five  genera  in  the  order,  which  may  be  distinguished  by 
the  following  key: 


236     Nerve-winged  Insects;   Scorpion-iiies;    Caddis-flies 

Simple  eyes  (ocelli)  absent. 

Wings  well  developed;    antennae  short  and  thick;    body  more  than  J  inch  long. 

Me  ROPE. 

Wings  rudimentary;    antennae  slender;    body  less  than  \  inch  long Boreus. 

Simple  eyes  (ocelli)   present. 

Abdomen  slender,  cylindrical;  not  ending,  in  males,  in  swollen  tip  with  clasping-organ. 

BiTTACUS. 

Abdomen  more  robust,  and  in  males  conspicuously  swollen  and    curved  at  tip,   and 
bearing  pointed  clasping-organ. 

Beak  elongate,  tarsal  claws   toothed Panorpa. 

Beak   short,    triangular;    tarsal   claws  simple Panorpodes. 


Boreus  is  the  genus  of  minute  leaping  black  insects  which  appear  occa- 
sionally in  snow.  Four  species  occur  in  this  country,  one,  B.  calijornkus 
on  the  Pacific  coast,  two  in  the  northern  and  northeastern  states,  and  one, 
B.  unicolor,  found,  so  far,  only  in  Montana.  Of  the  two  eastern  species,  the 
snow-born  Boreus,  B.  nivoriundus ,  is  shining  or  brownish  black,  with  the 
rudimentary  wings  tawny;  the  other,  called  the  midwinter  Boreus,  B. 
brnmalis,  is  deep  black-green.  Comstock  says  that  both  species  are  found 
on  the  snow  in  New  York  throughout  the  entire  winter,  and  that  they  also 
occur  in  moss  or  tree-trunks.  The  females  have  a  curved  ovipositor  nearly 
as  long  as  the  tiny  body.  Neither  their  feeding-habit  nor  life-history  is 
known. 

The  genus  Panorpa  includes  the  scorpion-flies,  of  which  fifteen  species 
are  found  in  the  United  States.  These  insects  are  from  J  to  f  inch  long, 
with  the  wings  of  about  the  same  length.  In  all,  the  body  is  brownish  to 
blackish  and  the  wings  are  clear  but  weakly  colored  with  yellowish  or 
brownish,  and  have  a  few  darker  spots  or  blotches,  which  in  one  or  two 
species  cover  nearly  the  whole  wing-surface.  Part  of  the  head  projects 
downwards  as  a  short  thick  beak,  the  mouth  and  jaws 
being  at  the  end.  The  few  observations  made  on  the 
feeding-habits  seem  to  show  that  the  scorpion-flies  sub- 
sist mainly  on  animal  matter  found  dead.     They  have 


Fig.  326. 

Fig.  326.^A  scorpion-fly,  Panorpa  rufescens. 
Fig.  327. — Larva  of  scorpion-fly,  Panorpa  sp. 


Fig.  327. 

(Twice  natural  size.) 

(After  Felt;  three  times  natural  size.) 


been  seen  to  attack  living  injured  and  helpless  insects.     Panorpa  riijesc 


ens 


Nerve-winged  Insects;   Scorpion-flies;    Caddis-flies    237 


(Fig.  326),  the  commonest  species  in  the  eastern  states,  lays  its  eggs,  accord- 
ing to  Felt,  in  crevices  of  the  ground;  the  larvas  (Fig.  327)  hatch  in  from 
six  to  seven  days  and  grow  rapidly.  They  burrow  in  the  soil,  but  not  deeply, 
and  spend  some  time  wandering  about  on  the  surface  hunting  for  food. 
They  are  full-grown  in  about  one  month,  probably.  The  further  life-history 
of  no  American  species  is  yet  known,  but  the  larva  of  a  European  species, 
when  full-fed,  burrows  deeper  in'o  the  ground,  e.xcavates  an  oval  cell  in 
a  small  'ump  of  earth  and  lies  in  it  for  several  months  before  pupating.  In 
this  condition  it  shrivels  to  one-half  of  its  previous  length,  and  the  body 
becomes  curved  backwards.  If  taken  out,  it  moves  slowly  and  cannot 
walk. 

The  species  of  the  genus  Bittacus,  of  which  there  are  nine  known  in 
our  country,  are  long-legged,  slender-bodied,  narrow-winged  insects  (a 
California  species  is  wingless)  which  do  not  resemble  the  scorpion-flies 
much  in  general  appearance,  but  have  a  similar 
beak  (although  longer  and  slenderer)  on  the 
head,  and  have  also  a  similar  venation  of  the 
wings.  All  the  species  as  far  as  known  are 
predaceous,  capturing  and  eating  various  kinds 
of  insects  and  probably  taking  no  food  except 
that  which  they  catch  alive.  Bittacus  strigosus 
(Fig.  3  8)  is  the  most  familiar  form  in  the  East. 
I  inhabits  shady  swamps  or  moist  coverts  along 
streams,  and  may  be  seen  restlessly  flitting  from 
branch  to  branch,  or  resting  for  short  times  sus- 
pended from  a  leaf  or  twig  by  its  long  fore  legs, 
sometimes  by  the  middle  ones  also.  Its  general 
appearance,  thus  suspended,  is  not  very  unlike 
a  bit  of  dried  dangling  foliage.  The  position 
appears  restful  and  one  might  almost  think  the 
insect  asleep.  "But  it  is  very  far  from  that," 
says  Felt,  "as  many  a  small  insect  could  testify 
were  it  still  alive.  The  small  fly  that  ventures  Fig. 
within  reach  of  the  long,  dangling  legs  imperils 
its  life.  In  a  second  those  well-armed  tarsi  seize  the  unfortunate,  the  fourth 
and  fifth  segments  of  the  tarsus  shutting  together  like  the  jaws  of  a  trap 
with  teeth  upon  their  opposing  surfaces.  The  struggle  is  usually  short; 
two,  three,  or  four  of  those  long  legs  lay  hold  of  the  captive  and  soon 
bring  it  within  reach  of  the  sharp  beak.  It  is  only  a  minute's  work 
to  pierce  a  soft  part  of  the  body  and  suck  the  victim's  blood,  when 
the  lifeless  remains  are  dropped  to  the  ground  and  the  insatiate  insect 
is  ready  for  the  next."     The  eggs  of  this  species  seem  to  develop  and  be 


,328.  —  Bittacus    strigosus. 
(Twice  natural  size.) 


238    Nerve-winged  Insects;   Scorpion-flies;    Caddis-flies 

dropped  a  few  at  a  time  during  the  adult  life.  So  far  as  observed, 
egg-laying  consists  simply  of  extruding  the  eggs  and  letting  them  drop  at 
random. 

The  habits  of  the  curious  wingless  species,  Bitiacus  apteriis,  common 
in  California,  have  been  observed  by  Miss  Rose  Patterson,  a  student  of 
Stanford  University.  These  long-legged,  thin-bodied  creatures  are  not 
readily  distinguished  among  the  drying  grass-blades  where  they  live,  because 
the  color  of  the  body  is  almost  exactly  like  the  yellowish  tan  of  the  plants. 
Miss  Patterson  went  into  the  field  one  windy  day  when  clouds  were  scudding 
over  the  sky.  At  first  not  a  scorpion-fly  was  to  be  seen;  then,  in  a  brief 
period  of  sunshine,  one  was  seen  swinging  itself  deliberately  along  from 
one  grass-blade  to  another.  When  the  wind  blew  hard  it  either  held  firmly 
to  the  weeds  or  dropped  down  to  the  ground  for  protection.  Finally  it  took 
up  its  position  near  a  flower-cluster  and  clung  by  all  its  tarsi.  When  a  bee- 
fly  came  passing  that  way  it  immediately  freed  two  of  its  legs  and  held  them 
out  in  an  attitude  of  expectancy.  When  the  fly  had  passed  it  remained 
in  that  position  for  a  minute  or  so  and  then  relaxed  into  what  seemed  a  more 
comfortable  attitude,  holding  on  by  all  tarsi.  As  it  became  cloudy  again, 
the  insect  dropped  down  among  the  weeds  and  remained  near  the  ground, 
its  legs  resting  on  the  grass-stems  and  its  abdomen  pointing  almost  directly 
outwards.  Miss  Patterson  disabled  a  small  skipper  butterfly  and  dropped 
it  near  the  Bittacus,  but  he  seemed  to  pay  no  attention.  A  lady-bug  did 
not  arouse  him.  A  fly  passed  over  and  still  he  did  not  move.  She  touched 
him  with  a  pencil-point  and  he  drew  back  and  began  to  feign  sleep.  When 
she  continued  to  disturb  him  he  showed  an  inclination  to  fight,  but  did  not 
leave  his  shelter  until  she  forced  him  to  do  so  by  repeated  pokes  with  the 
pencil-point.  Then  he  ran  nimbly  to  the  top  of  a  blade  of  grass  and  hung 
there:  his  tarsi  went  scarcely  around  the  leaves.  He  remained  in  that  posi- 
tion, motionless,  until  a  bird  twittered  overhead;  then  he  promptly  found 
a  sheltered  place  in  a  drooping  grass-leaf. 

Near  him  she  discovered  another  scorpion-fly,  with  a  crane-fly  in  its 
clutches.  The  crane-fly  was  still  alive  and  struggled  feebly  while  the  scor- 
pion-fly sucked  its  blood.  She  disturbed  them,  but  though  the  scorpion- 
fly  stopped  its  eating,  it  held  its  prey  as  before  and  moved  slowly  off  with 
it.  The  body  of  the  crane-fly  was  almost  cut  in  two  by  the  grasping  tarsi  of 
its  enemy. 

Finding  another  of  the  queer  creatures  swinging  on  a  weed,  its  four  legs 
held  out  hungrily,  she  gave  it  a  crane-fly,  which  it  grasped  firmly,  winding 
the  tarsi  around  its  body.  The  crane-fly  struggled,  but  its  captor  soon  had 
its  head  buried  almost  to  the  eyes  in  its  body.  Finally  the  mangled  crane- 
fly  gave  out.  She  caught  another  crane-fly  and  held  it  out  to  the  scorpion- 
fly,  which  thereupon  grasped  its  first  victim  firmly  in  one  of  its  hind  tarsi 


Nerve-winged  Insects;   Scorpion-flies;   Caddis-flies   239 

and  snatched  at  the  second.  Then  holding  both,  it  began  to  suck  the  blood 
of  the  fresher  prey. 

Bringing  some  scorpion-flies  into  the  laboratory,  Miss  Patterson  placed 
a  crane-fly  in  the  jar  with  a  pair  of  them.  The  male  scorpion-fly  seemed 
unusually  hungry  and  soon  caught  its  prey  and  began  to  eat.  The  female 
paid  no  attention  until  the  male  had  eaten  for  some  time.  Then  Miss  Pat- 
terson observed  the  male  to  bend  the  posterior  portion  of  its  abdomen,  and 
between  the  sixth  and  seventh  and  seventh  and  eighth  segments  on  the 
norsal  side  of  the  body  rounded  organs  were  quickly  protruded  and  with- 
drawn. Shortly  after  this  the  female  approached  and  also  began  to  eat 
the  crane-fly.  Several  times  she  noted  the  males  attracting  the  females  by 
protruding  the  "scent-glands."  In  every  case,  when  the  male  began  to  give 
off  the  scent,  the  female  gradually  approached. 

Eggs  were  laid  by  the  females  in  the  laboratory  jars.  These  eggs  were 
pink  in  color  and  spherical,  although  slightly  flattened  at  opposite  sides. 
They  are  simply  dropped  by  the  female  loosely  and  singly  to  the  ground. 

In  the  Rocky  Mountains  of  northern  Colorado  are  some  of  the  most 
attractive  "camping-out"  places  in  our  land;  that  is,  for  "campers"  who 
specially  like  Nature  in  her  larger,  more  impressive  phases.  The  peaks 
of  the  Front  Range  rise  to  14,000  feet  altitude,  and  the  ice-  and  water-worn 
canons  and  great  sheer  cliffs  of  the  flanks  of  the  Range  are  only  equalled 


Fig.  329. — Phryganea  cinerea.     (After  Needham;  enlarged.) 

in  this  country  by  the  similar  ones  of  the  Californian  Sierra  Nevada.  The 
mountain-climber  in  these  wild  regions  cannot  but  interest  himself  in  the 
animal  and  plant  life  which  he  finds  struggling  bravely  for  foothold  in  even 
the  roughest  and  most  exposed  places.  To  the  entomologist  the  few 
hardy  butterfly  kinds  of   the    mountain-top,  the  scarce  inhabitants  of  the 


240   Nerve- winged  Insects;   Scorpion-flies;    Caddis-flies 

heavy  spruce  forests,  and  the  strange  aquatic  larvae  desperately  clinging 
to  the  smooth  boulders  and  rock  bed  of  the  swift  mountain  streams  are 
among  the  most  interesting  and  prized  of  all  the  insect  host.  So  it  was 
that  my  first  summer's  camping  and  climbing  in  the  Rockies  acquired  a 
special  interest  from  the  slight  acquaintanceship  I  then  made  with  a  group 
of  insects  which,  unfortunately,  are  so  little  known  and  studied  in  this 
country  that  the  amateur  has  practically  no  written  help  at  all  to  enable 


Fig.  330. — Leptocerus  resurgens.     (After  Needham;   enlarged.) 

him  to  become  acquainted  with  their  different  kinds.  These  insects  are 
the  caddis-flies;  not  limited  in  their  distribution  by  any  means  to  the  Rocky 
Mountains,  but  found  all  over  the  country  where  there  are  streams.  But 
it  is  in  mountain  streams  that  the  caddis-flies  become  conspicuous  by  their 
own  abundance  and  by  the  scarcity  of  other  kinds  of  insects. 

In  Europe  the  caddis-flies  have  been  pretty  well  studied  and  more  than 
500  kinds  are  known.  In  this  country  about  150  kinds  have  been  deter- 
mined, but  these  are  only  a  fraction  of  the  species  which  really  occur  here- 
Popularly  the  adults  are  hardly  known  at  all,  the  knowledge  of  the  group 
being  almost  restricted  to  the  aquatic  larvas,  whose  cleverly  built  protecting 
cases  or  houses  made  of  sand,  pebbles,  or  bits  of  wood  held  together  with 
silken  threads  give  the  insects  their  common  name,  i.e.,  case-  or  caddis- 
worms.     The  name  of  the  caddis-fly  order  is  Trichoptera. 

These  cases  are  familiar  objects  in  most  clear  streams  and  ponds.. 
Figures  331  and  332  show  several  kinds.  There  is  great  variety  in  the 
materials  used  and  in  the  size  and  shape  of  the  cases,  each  kind  of  caddis- 
worm  having  a  particular  and  constant  style  of  house-building.  Grains 
of  sand  may  be  fastened  together  to  form  tiny,  smooth-walled,  s^-mmetrical 
cornucopias,  or  small  stones  to  form  larger,  rough-walled,  irregular  cylinders. 
Small  bits  of  twigs  or  pine-needles  may  be  used;    and  these  chips  may  be 


Nerve-winged  Insects;   Scorpion-flies;    Caddis-flies    241 


laid  longitudinally  or  transversely  and  with  projecting  ends.  Small  snail- 
shells  or  bits  of  leaves  and  grass  may  serve  for  building  materials.  One  kind 
of  caddis-worm  makes  a  small,  coiled  case  which  so  much  resembles  a  snail- 
shell  that  it  has- actually  been  described  as  a  shell  by  conchologists.  Some 
cases  in  California  streams  gleam  and  sparkle  in  the  water  like  gold;  bits 
of  mica  and  iron  pyrites  were  mixed  with  other  bits  of  mineral  picked  up 
from  the  stream  -  bed  to  form 
these  brilliant  houses.  An  Eng- 
lish student  removed  a  caddis- 
worm  from  its  case,  and  pro- 
vided it  only  with  small  pieces 
of  clear  mica,  hoping  it  would 
build  a  case  of  transparent  walls. 
This  it  really  did,  and  inside  its 
glass  house  the  behavior  of  the 
caddis  -  worm  at  home  was  ob- 
served.    While  most  of  the  cases 

are  free  and  are  carried  about  by  Ji^^^  \Ol?        '-^t^ 

the  worm  in  its  ramblings,  some  Fig.  331.  Fig.  332a.       Fig.  3326. 

are  fastened    to    the    boulders  or  Fig.  331.— Two  cases  of  caddis-worms.    (Natu- 

rock  banks  or  bed  of  the  stream.  fig'!^32.-Two  cases  of  caddis-worms  with  the 
These  fixed  cases  are  usually  com-  larval  insects  within  showing  head  and  thorax 
posed  of  bits  of  stone  or  smooth  P'-oJecting.  (Natural  size.) 
pebbles  irregularly  tied  together  with  silken  threads.  In  all  the  cases  silk 
spun  by  the  caddis-worm  is  used  to  tie  or  cement  together  the  foreign  build- 
ing materials,  and  often  a  complete  inner  silken  hning  is  made. 


Fig.    333. — Halesus  indistinctus.     (After  Needham;     enlarged.) 


The  larvae  within  the  cases  are  worm-  or  caterpillar-like,  with  head  and 
thorax  usually  brown  and  horny-walled,  while  the  rest  of  the  body  is  soft 
and  whitish.  The  head  with  the  mouth-parts,  and  the  thorax  with  the  long 
strong  legs,  are  the  only  parts  of  the  body  that  project  from  the  protecting 
case,  and  hence  need  to  be  specially  hardened.     At  the  posterior  tip  of  the 


242    Nerve-winged  Insects;   Scorpion-flies;    Caddis-flies 


abdomen  is  a  pair  of  strong  hooks  pointing  outward.  These  hooks  can 
be  fastened  into  the  sides  of  the  case  and  thus  hold  the  larva  safely  in  its 
house.  Numerous  thread-like  tracheal  gills  are  borne  on  the  abdomen 
and  by  a  constant  undulatory  or  squirming  motion  of  the  body  a  stream  of 
fresh  water  is  kept  circulating  through  the  case,  thus  enabling  the  gills  to 
effect  a  satisfactory  respiration.  The  caddis-worm  crawls  slowly  about 
searching  for  food,  which  consists  of  bits  of  vegetable  matter.  Those  larvae 
which  have  a  fixed  case  have  to  leave  it  in  search  of  food.  Some  of  them 
make  occasional  foraging  expeditions  to  considerable  distances  from  home. 
Others  have  the  interesting  habit  of  spinning  near  by  a  tiny  net  (Fig.  335), 


334. — Hydropsyche  scalaris.     (After  Needham;    enlarged.) 


fastened  and  stretched  in  such  a  way  that  its  broad  shallow  mouth  is  directed 
up-stream,  so  that  the  current  may  bring  into  it  the  small  aquatic  creatures 
which  serve  these  caddis-fishermen  as  food.  The  caddis-flies  live  several 
months,  and  according  to  Howard  some  pass  the  winter  in  the  larval  stage. 
When  the  caddis-worms  are  ready  to  transform  they  withdraw  wholly 
into  the  case  and  close  the  opening  with  a  loose  wall  of  stones  or  chips  and 
silk.  This  wall  keeps  out  enemies,  but  always  admits  the  water  which  is 
necessary  for  respiration.  The  pupae  in  the  well-made  cases  have  no  other 
special  covering,  but  in  the  simple  rough  pebble  houses  attached  to  stones 
in  the  stream  they  are  enclosed  in  thin  but  tough  cocoons  of  brown  silk 
spun  by  the  larvae.  The  free  cases  are  also  usually  attached  just  before 
pupation  to  submerged  sticks  or  stones.  When  ready  to  issue  the  pupa 
usually  comes  out  from  the  submerged  case,  crawls  up  on  some  support 
above  water  and  there  moults,  the  winged  imago  soon  flying  away.  Some 
kinds,  however,  emerge  in  the  water.  Comstock  observed  the  pupa  of  one 
of  the  net-building  kinds  to  swim  to  the  surface  of  the  water  (in  an  aqua- 
rium) by  using  its  long  middle  legs  as  oars.  The  insect  was  unable  to  crawl 
up  the  vertical  side  of  the  aquarium,  so  the  observer  lifted  it  from  the  water 
on  a  stick.  At  this  time  its  wings  were  in  the  form  of  pads,  but  the  instant 
the  creature  was  free  from  the  water  the  wings  expanded  to  their  full  size 
and  flew  away  several  feet.     On  attempting  to  catch  the  specimen  Com 


Nerve-winged  Insects;   Scorpion-flies;   Caddis-flies   243 

stock  found  that  it  had  perfect  use  of  its  wings,  aUhough  they  were  so  recently 
expanded.  The  time  required  for  the  insect  to  expand  its  wings  and  take 
its  first  flight  was  scarcely  more  than  one  second;  certainly  less  than  two. 
As  such  caddis-flies  normally  emerge  from  rapidly  flowing  streams  which 
dash  over  rocks,  it  is  evident  that  if  much  time  were  required  for  the  wino-s 
to  become  fit  for  use,  as  is  the  case  with  most  other  insects,  the  wave  succeed- 
ing that  which  swept  one  from  the  water  would  sweep  it  back  again  and 
destroy  it. 


Fig.  336. 

Fig.  335. — Fishing-net  of  caddis-worm  in  stream.     (After  Comstock.) 
Fig.  336. — Goiiiotatiliiis  dispectus.     (After  Needham;  enlarged.) 

The  adult  caddis-flies  are  practically  unknown  to  general  students. 
They  are  mostly  obscurely  colored,  rather  small,  moth-like  creatures,  that 
limit  their  flying  to  short,  uncertain  excursions  along  the  stream  or  pond 
shore,  and  spend  long  hours  of  resting  in  the  close  foliage  of  the  bank. 
So  far  as  observed  the  flies  take  no  food,  although  in  all  the  specimens  I 
have  examined  there  are  fairly  well-developed  mouth-parts  fitted  for  lap- 
ping up  liquids.     They  probably  do  not  live  long,  and  certainly  do  not  live 


Fig.  337. — TricBiiodes  ignita.     (After  Needham;    enlarged.) 

excitingly.  In  the  Colorado  mountains  numerous  small  species  occur, 
some  w!th  beautiful  snow-white  wings  and  delicate  blue-green  bodies  (Setodes) ; 
other  black-winged,  brown-bodied  kinds  (Mystacides) ;  and  other  light- 
brown  winged  species  (Hydropsyche)  in  great  abundance,  but  usually  the 
adults  are   comparatively  solitary  and  inconspicuous.     They  probably  fly 


244   Nerve-winged  Insects;   Scorpion-flies;    Caddis-flies 

chiefly  at  night,  as  large  numbers  have  been  taken  in  trap  lanterns  by  Betten. 
The  eggs  are  laid,  according  to  this  observer,  in  or  directly  above  the  water 
Many  clusters  of  eggs  were  found  under  the  bark  of  submerged  trees,  which 
would  lead  to  the  conclusion  that  in  some  cases  the  female  insect  goes  under 
water  to  deposit  the  eggs.  A  spherical  cluster  found  suspended  on  a  sub- 
merged twig  under  a  log  floating  in  deep  water  contained  450  eggs. 

Some  of  the  caddis-fly  larvae  can  be  readily  kept  in  an  aquarium. 
Almost  any  kinds  found  in  ponds  will  live  in  aquariums,  where  their  feed- 
ing-habits and  transformation  may  be  observed.  The  caddis-worms  that 
build  odd  cases  of  small  sticks  laid  crosswise  live  contentedly  in  an 
aquarium  and  are  most  interesting  to  watch.  The  complete  life-history 
of  no  single  caddis-fly  species  has  yet  been  worked  out  completely,  and  the 
specific  identity  of  but  few  of  our  larvae  is  known.  For  three  California 
species  Geo.  Coleman,  a  student  of  Stanford  University,  has  obtained  adults 
by  putting  wire-screen  cages  over  the  larvae  in  the  streams.  In  these  cages 
the  larvae  had  room  enough  to  hunt  food  successfully,  and  they  lived,  except 
for  the  circumscribing  of  their  territory,  perfectly  naturally.  Betten  has 
similarly  reared  imagoes  from  four  kinds  of  larvae  in  the  Adirondack  Moun- 
tains. 

The  following  keys  will  enable  the  collector  to  classify  either  his  caddis- 
worms  (larvae)  or  caddis-flies  (adults)  to  families: 

KEY  TO  FAMILIES  (ADULTS). 

Spines  on  the  legs,  three  simple  eyes  (ocelli). 

Four  spurs  on  tibiae  (second  long  segment)  of  middle  legs Phryganid^. 

Two  or  three  spurs  on  middle  tibiae Limnephilid^. 

No  spines  on  legs,  only  hairs  or  spurs. 

Last  two  segments  of  palpi  (mouth-feelers)  not  elongated  and  flexible. 

Palpi  of  males   5-segmented;     ocelli   often   present Rhyacophilid^. 

Palpi  of  males  4-segmented;    ocelli  absent. 

No  spurs  on  front  legs Hydroptilid^. 

Spurs  on  front  legs Sericostomatid.e. 

Last  segment  of  palpi  elongate  and  flexible;    palpi  hairy. 

Basal  segment  of  antennas  long  and  thick,  wings  slender,  no  ocelli. . .  .Leptocerid.e. 

Basal  segment  of  antenna  shorter,  wings  broader,  last  segment  of  palpi  composed 

of  numerous  subsegments Hydropsychid.e. 

KEY  TO  FAMILIES  {^ARYJE).     (After  Betten.) 

Larva  with  head  bent  downward  at  an  angle  with  the  body;  tubercles  generally  present 
on  the  first  abdominal  segment;  lateral  fringe  generally  present;  gill  filaments, 
when  present,  usually  simple. 

Hind  legs  more  than  twice  as  long  as  the  first  pair;  cylindrical  case  of  sand  and  small 
stones Leptocerid.e. 

Hind  legs  not  more  than  twice  as  long  as  first  pair. 


Nerve-winged  Insects;   Scorpion-flies;    Caddis-liies    245 

Head  elliptical,  only  pronotum  (dorsal  wall  of  prothorax)  chitinized  (horny  and 
dark),  abdominal  constrictions  deep;  cases  of  vegetable  matter  laid  longitudi- 
nally and  forming  a  spiral,  widening  at  front  end Phryganeid^. 

Head  oval  to  circular,  pronotum  chitinized,  mesonotum  often,  and  metanotum  some- 
times chitinized,  abdominal  constrictions  slight. 

Lateral  fringe  well  developed;    cases  various Limnophilid.e. 

Lateral   fringe   slightly   developed;     cylindrical   case  of  sand   or  small   stones. 

Sericostomatid.5. 
arva   with  head  projecting  straight  forward  in   line   with  the  rest  of  body;    tubercles 

and  lateral  fringe  wanting;    gill-filaments,   when  present,   branched. 
Abdomen  much  thicker  than  the  thorax;    case  kidney-shaped,  of  small  stones,  or  flat 

and  parchment-like Hydroptilid^. 

Abdomen  little  if  any  thicker  than  the  thorax. 

Third  pair  of  legs  a  little  longer  than  the  first  pair;   no  larval  case.  .Rhyacophilid^,. 
Third  pair  of  legs  about  the  same  length  as  first  pair;    no  portable  larval  case. 

Hydropsychid^. 


CHAPTER   XII 
THE  BEETLES  (Order  Coleoptera) 

I  HE  moths  and  butterflies  (Lepidoptera)  and  the 
beetles  (Coleoptera)  are  the  most  familiar  of  the 
insect  orders.  They  are,  too,  most  affected  by 
collectors:  of  all  the  amateur  collectors  of  insects 
probably  nine  out  of  ten  collect  either  Lepi- 
doptera or  Coleoptera,  or  perhaps  both.  The 
moths  and  butterflies  obviously  owe  their  special 
attractiveness  to  their  beautiful  colors  and  pat- 
terns, and  to  the  interesting  metamorphoses 
exhibited  in  their  life-history.  A  gratifyingly 
increasing  number  of  amateurs  and  collectors  are 
"rearing"  or  breeding  Lepidoptera,  and  adding  much  to  our  scientific  knowl- 
edge of  them.  The  beetles  owe  their  place  of  honor  among  collectors  largely 
to  their  abundance  of  species  and  individuals,  the  readiness  with  which 
they  can  be  collected,  and  the  little  special  attention  necessary  to  their  per- 
fect preserv^ation.  They  are  mostly  large  enough,  too,  to  be  handled  and 
examined  readily,  and  not  so  large  as  to  require  much  cabinet  space  for 
their  keeping.  They  also  make  specially  fit  specimens  for  exchange.  But 
amateurs  give  almost  no  attention  to  the  immature  stages  of  beetles. 
Although,  like  the  Lepidoptera,  they  undergo  a  complete  metamorphosis,  the 
larvae  are  so  obscure  and  usually  so  concealed  underground  or  in  tree-trunks 
or  decaying  matter  or  in  the  water,  or,  if  seen,  are  so  often  unattractive  and 
even  repulsive  in  appearance — most  beetle-larvae  are  "grubs" — that  rearing 
beetles  is  practically  an  unknown  pastime  even  with  the  professed  "coleop- 
terists." 

As  a  matter  of  fact,  the  beetles  do  not  begin  to  present  an  interest  even 
to  professional  entomologists  at  all  in  proportion  to  the  dominant  number 
of  species  in  the  order.  There  is  a  curious  uniformity — with  of  course  the 
startling  exceptions  which  must  be  mentioned  in  the  same  breath  with 
almost  any  generalization  about  insects — in  the  general  character  of  the 
structure,  development,  and  habits  throughout  most  of  the  great  order  of 
beetles.     So  that  a  few  life-histories  well  worked  out  give  us  a  fair  knowledge 

of  the  principal  characteristics  of  coleopterous  development. 

246 


.A 


PLATE   II. 

BEETLES. 

i  =  Desmocerus  palliatus. 
2  =  Tragidion  armatum. 
3=Chalcophora  liberta. 
4=  Chrysochus  auratus, 
5  =  Silpha  amftrrivana. 
6=GeotrupJes  splendidus 
7  =  Chrysochus  cobaltinus 
8=Bupr'estis  sp. 
9=  Calosoma  scrutator 
io=  Tc-traopes  tetraophthahnu; 
ix  =  Cucujus  platipes. 
i2^Meloc  sp. 
i3=PeHdnota  punctata. 
i4=Parandra  brunnea. 
i5=Cyllene  robiniae. 
i6=RosaHa  funebris. 
i7=Cicindela  genetosa. 


PLATE    II 


!\rayy  Jle/lmnn,  ,iel. 


Beetles 


247 


It  would  be  reasonable  to  expect  to  find  the  insects  of  an  order  so  pursued 
bv  collectors  susceptible  of  ready  classifying  and  determining.  On  the 
contrary,  no   order   presents   more   difficulty   to   the   elementary  and   even 


labial  palpi 


labium 
compound  eye- 


mouth-parts 

maxi^la'Ty  palpi 
^head 
/intenna. 


y 

'prothorax 

.mesothorax 

metathorax 


coxa- 

trochanter— 


femur'''% 
tibia^' 


tarsal  segme7i{s 


abdomen 


Fig.  338. — Ventral  aspect  of  male  great  water-scavenger  beetle,  Hydrophilus  sp. 
(Three  times  natural  size.) 

advanced  students  of  systematic  entomology.  The  tables  and  keys  pre- 
pared by  the  few  specialists  really  competent  to  determine  accurately  the 
different  species  of  beetles  are  as  nearly  impossible  to  the  amateur  and 
elementary  student  as  any  "keys"  in  all  the  field  of  classific  entomology. 


248 


Beetles 


The  characters  made  use  of  in  separating  species,  genera,  and  even  families 
are  so  slight,  obscure,  and  difficult  to  understand  that  the  tables  and  keys 
based  on  them  chiefly  result  in  wholly  discouraging  any  beginner  who 
attempts  to  use  them.  And  this  is  not  so  much  the  fault  of  the  systematic 
specialists  as  of  the  beetles  themselves.     When  it  is  recalled  that  nearly 


brain 
oesophagus- 


elytron 


..-go-nglia 


r^Mlimentary 
canal 
^_  ventral  nerve 
chain 


oviduct'^ '  ^99-ti 
accessory  glandi-'  Yectuvi 


Malpighian 
intestine        tubules 

\receptaculum  seminalis 
Fig.    33Q. — Dissection   of   female   great   water-scavenger   beetle,    Hydrophihis  sp.; 
heart  and  air-tubes  (trachea;)  are  cut  away.     (Three  times  natural  size.) 


the 


12,000  species  of  this  order  are  known  in  North  America  north  of  Mexico; 
that  they  represent  nearly  2000  genera,  grouped  in  80  families;  and  that 
much  general  similarity  of  structure  as  well  as  of  habits  prevails  through- 
out the  order,  it  begins  to  be  apparent  whv  difficulties  in  classification  are 
inevitable.     To  find  structural  differences  among  these  thousands  of  beetles, 


Beetles 


249 


the  specialists  have  been  driven  to  turn  their  microscopes  on  the  most  obscure 
and  insignificant  parts  of  the  body,  and  to  take  cognizance  of  the  shghtest 
appreciable  constant  differences.  The  real  way  in  which  an  entomologist 
gets  his  beetles  classified  is  to  submit  specimens  to  a  specialist  for  determina- 
tion. Then  as  his  authoritatively  determined  collection  gradually  increases, 
the  collector  begins  to  get  acquainted  with  certain  well-marked  species,  and 
also  with  the  general  appearance  or  habitus  of  the  members  of  any  one  family. 
He  becomes  in  time  able  to  classify  his  new  specimens  to  families,  not  bv 
tables  or  keys,  but  by  general  appearance  and  a  certain  few  characteristic 
structural  peculiarities,  and  to  determine  some  species  by  comparison  with 
the  already  classified  specimens  in  his  collection.  The  eye  thus  gradually 
trained  becomes  more  and  more  discriminating,  and  the  collector  may  in 
time  come  to  be  a  recognized  "coleopterist"  both  by  virtue  of  his  large  col- 
lection and  the  rare  forms  it  contains  and  by  his  wide  personal  ac- 
quaintanceship with  beetle  species.  In  the  necessarily  limited  account  of 
the  Coleoptera  given  in  the  following  pages  I  purpose  to  give  keys  only  to 
tribes  and  families,  and,  in  order  to  make  even  these  simple  enough  to  be 
useful,  to  leave  most  of  the  small,  rare,  and  obscure  families  wholly  out  of 
consideration. 

The  tables  thus  freed  of  over  half  the  families  of  the  order  still  include 
five-sixths  of  all  the  North  American  beetle  kinds,  and  will  be  found  to  include 
nine  out  of  every  ten  beetle  species  collected.  That  is,  the  great  proportion, 
ninety  per  cent,  probably,  of  species  at  all  common  enough  to  be  collected 
belong  to  less  than  half  of  the  recognized  families.  These  more  familiar 
families  can  also  be  grouped  into  a  few  tribes,  each  having  some  simple 
common  structural  characteristic,  thus  still  further  aiding  in  the  work  of  the 
classifier.  The  collector  will  thus  first  classify  his  specimen  to  a  tribe  by 
means  of  the  table  on  page  251,  and  then  turning  to  a  discussion  of  that 
particular  tribe  find  a  key  to  its  families.*  In  the  discussion  of  each  of 
these  will  be  found  accounts  of  the  life  of  certain  of  the  more  abundant,  wide- 
spread, and  interesting  species  of  the  family. 

The  characteristics  of  the  order  as  a  whole  are  obvious  and  familiar: 
most  beetles  are  readily  known  for  beetles,  and  but  few  insects  of  other  orders 
get  mistaken  for  them.  The  "black  beetle"  of  the  house  is  a  cockroach, 
and  several  of  the  hard-bodied,  blackish  sucking-bugs  are  sometimes  mis- 
takenly called  beetles,  as  are  also  the  earwigs.  But  the  horny  fore  wings, 
elytra,  serving  as  a  sheath  for  the  large  membranous  hind  wings,  the  true 

*  If  the  collector  wishes  a  further  determination  of  his  specimens,  he  must  do  as  prac- 
tically all  other  amateur  and  most  professional  entomologists  do;  that  is,  send  his 
material  to  a  specialist,  who  has,  by  the  way,  the  right  recognized  by  custom  of  keeping 
any  of  these  specimens  sent  him,  to  add  to  his  own  cabinets,  ft  is  well,  therefore,  to 
send  an  extra  specimen  to  return  in  the  case  of  any  species  likely  to  interest  him. 


250 


Beetles 


organs  of  flight;  the  firm,  thick,  usually  dark,  chitinized  cuticle  or  outer 
body-wall;  the  strong-jawed  biting  mouth,  and  the  compact  body,  usually 
short   and   robust,   are   structural   characteristics  obvious   and   usually   dis- 


FiG.  340. — The  different  forms  of  antennae  of  beetles,  i,  serrate;  2,  pectinate;  3,  cap- 
itate (and  also  elbowed);  4-7,  clavate;  8-9,  lamellate;  10,  serrate;  11,  irregular 
(Gyrinus);     12,    2-segmented   antennse   of   Adranes  ccbcus.     (After   LeConte.) 

tinctive.  Especially  used  in  classification  are  the  differences  in  number 
of  tarsal  segments  of  the  feet,  and  differences  in  the  character  of  the  antennae. 
To  learn  the  range  of  these  differences  in  the  antennae,  and  the  names  applied 
to  the  various  kinds  a  careful  inspection  of  Fig.  340  will  do  more  than  a 
4 


Fig.  341. — Different  forms  of  legs  and  tarsi  of  beetles.     (After  LeConte  and  Comstock.) 

page  of  description.     Similarly  Fig.  341  illustrates  the  range  of  the  charac- 
ters drawn  from  the  tarsi. 

The  development  of  beetles  is  "with  complete  metamorphosis  ";  that  is, 
from  the  eggs  laid  underground,  or  on  leaves  or  twigs,  in  branches  or  trunks 
of  live  trees,  in  fallen  logs,  on  or  in  decaying  matter,  in  fresh  water,  etc., 


Beetles 


251 


hatch  larvae  usually  called  grubs,  with  three  pairs  of  legs  (sometimes  want- 
ing), with  biting  mouth-parts,  simple  eyes,  and  inconspicuous  antennae. 
These  larva2  are  predaceous,  as  the  water-tigers  (larvae  of  water-beetles), 
plant-feeders,  as  the  larva?  of  the  long-horns,  or  carrion-feeders,  as  those  of  the 
burying-beetles,  and  so  on.  They  grow,  moult  several  times,  and  finally  change 
into  a  pupa  either  on  or  in  the  food,  or  very  often  in  a  rough  cell  under- 
ground. From  the  pupa  issues  the  fully  developed  winged  beetle,  which 
usually  has  the  same  feeding-habits  as  the  larva.  The  special  food-habits 
and  characteristics  of  development  are  given  for  numerous  common  species 
in  the  accounts  (postea)  of  the  various  more  important  families  of  the  order. 

The  enonomic  status  of  the  order  Coleoptera  is  an  important  one.  So 
many  of  the  beetles  are  plant-feeders,  and  are  such  voracious  eaters  in  both 
larval  and  adult  stages,  that  the  order  must  be  held  to  be  one  of  the  most 
destructive  in  the  insect  class.  Such  notorious  pests  as  the  Colorado  potato- 
beetle,  the  two  apple-tree  borers,  round-headed  and  flat-headed,  the  "buffalo- 
moth"  or  carpet-beetle,  the  wireworms  (larvae  of  click-beetles),  the  white 
grubs  (larvs  of  June  beetles),  rose-chafers,  flea-beetles,  bark-borers  and 
fruit-  and  grain-weevils,  are  assuredly  enough  to  give  the  order  a  bad  name. 
But  there  are  good  beetles  as  well  as  bad  ones.  The  little  ladybirds  eat 
unnumbered  hosts  of  plant-lice  and  scale-insects;  the  carrion-beetles  are 
active  scavengers,  and  the  members  of  the  predaceous  families,  like  the 
Carabids  and  tiger-beetles,  undoubtedly  kill  many  noxious  insects  by  their 
general  insect-feeding  habits. 

The  great  order  Coleoptera  is  divided  into  two  primary  groups,  some- 
times called  suborders,  namely,  Coleoptera  genuina,  the  typical  or  true 
beetles,  including  those  species  in  which  the  mouth-parts  are  all  present  and 
the  front  of  the  head  is  not  elongated  into  a  beak  or  rostrum,  and  the 
Rhynchophora,  snout-beetles  (p.  294),  which  have  the  front  part  of  the 
head  more  or  less  extended  and  projecting  as  a  beak  or  rostrum,  and  the 
mouth-parts  with  the  labrum  (upper  Up)  so  reduced  as  to  be  indistinguish- 
able and  the  palpi  reduced  to  mere  stiff  jointless  small  processes.  To 
this  latter  suborder  belong  those  beetles  familiarly  known  as  weevils,  bill- 
bugs,   bark-beetles,  and  snout-beetles. 

KEY  TO  SECTIONS  AND  TRIBES  OF  COLEOPTERA  GENUINA. 

With  five  tarsal  segments  in  all  the  feet  (with  rare  exceptions).  Section  Pentamera.  (p.  252). 
With   the    antennae   slender,    thread-like,    with    distinct,    cylindrical    segments. 

(Carnivorous  beetles.)     Tribe  Adephaga  (p.  252). 
With  the  antennas  thickened  gradually  or  abruptly  toward  the  tip. 

(Club-horned  beetles.)     Tribe  Clavicornia  (p.  258). 
With  the  antennae  serrate  or  toothed. 

(Saw-horned  beetles.)    Tribe  Serricornia  (p.  265). 

With  the  antennae  composed  of  a  stem-like  basal  part,  and  a  number  of  flat  blade-like 

segments  at  the  tip.    (Blade-horned  beetles.)    Tribe  Lamellicornia  (p.  272). 


252 


Beetl 


es 


With  four  tarsal  segments  in  each  of  the  feet Section  Tetramera  (p.  277). 

Mostly  with  slender  cylindrical  antennte,  sometimes  very  long  and  thread-like, 
sometimes  shorter  and  thickened  toward  the  tip;  the  fourth  and  fifth  seg- 
ments of  the  tarsus  closely  fused,  the  fourth  segment  being  very  small  and 
sometimes  difficult  to  distinguish. 

(Plant-eating  beetles.)     Tribe  Phytophaga  (p.  277). 

With  three  tarsal  segments  in  each  of  the  feet Section  Trimera  (p.  286). 

With  the  front  and  middle  legs  with  5-seginented  tarsi,  and  the  hind  legs  with  4-seg- 
mented  tarsi Section  Heteromera  (p.  288). 

SECTION   PENTAMERA. 

In  the   tribe  of  Adephaga,   or    carnivorous  beetles,   are  four  principal 
families,  which  may  be  distinguished  by  the  following  key: 
Terrestrial. 

Antennae  inserted  on  front  of  the  head  above  the  base  of  the  mandibles. 

(Tiger-beetles.)     Cicindelid^. 

Antennce  inserted  on  side  of  the  head  between  the  base  of  the  jaws  and  the  eyes. 

(Predaceous  ground-beetles.)     Carabid^e. 
Aquatic. 

With  two  eves (Predaceous  diving-beetles.)     Dytiscid^. 

With  four  eyes,  two  above  and  two  below (Whirligig-beetles.)     Gyrinid^. 

The  attractive  tiger-beetles  (Cicindelidae)  are  great  favorites  with  col- 
lectors, and  deservedly.  Their  vivid,  sharply  marked  metallic  colors,  trim 
clean  body,  and  constant  alertness  and  activity,  together  with  their  fond- 
ness for  warm,  bright  hunting-grounds  and  their  clever  and  "gamy" 
elusiveriess  of  the  collecting-net,  combine  to  give  these 
fierce,  swift  little  creatures  a  high  place  in  the  regard  of 
the  beetle-catching  sportsman.  There  are  but  four  genera 
in  the  family,  but  the  genus  Cicindela  contains  about 
sixty  species,  distributed  over  the  whole  country.  In 
California  we  are  not  provided  with  quite  our  share  of  tiger- 
beetles,  but  then  there  are  not  so  many  Cicindelid-hunters 
as  in  the  East.  Look  for  tiger-beetles  on  sunny  days  in 
hot  dusty  roads  or  open  sandy  spots.  In  cold  and  cloudy 
weather,  and  at  night,  they  lie  hidden  under  stones  or 
chips  or  in  burrows,  although  a  few  species  are  nocturnal 
in  habit.  When  out  and  running  or  flying  about  they  are 
hunting;  their  big  eyes  and  long  sharp  mandibles  and  the 
whole  seeming  of  the  body  some  way  betray  their  predatory 
habits  even  before  one  sees  the  swift  pounce  on  some 
dull-witted,  slow-footed  insect,  and  the  eager  blood- 
drinking  immediately  thereafter. 
The  egg-laying  habit  of  the  tiger-beetles  is  not  yet  known,  but  the  larvae 
and   their   habits   are   familiar.     They   are   ugly,   malformed,   strong-jawed 


Fig.  342. — Larva 
of  a  tiger- 
beetle,  Cicindela 
hybrida.  (After 
Schiodte ;  three 
times  natural 
size.) 


PLATE   III 


TIGER  BEETLES.     (After  Lcng  and  Bcutenmuller.) 


Ig.    I.     Tctracha  Carolina. 

"      2.     Cicindela  unipunctata 

"      3- 

'         celeripes. 

"      4 

'         dorsal  is. 

"      5  •           ' 

'         scutellaris  var.  rugifrons. 

"      6 

'         longilabris 

7 

'                 "         var.  pcrviridis 

"      8 

'         scutellaris  var.  Lecontei 

"      9 

'        sexguttata. 

"      lO                 ' 

'                 "         var.  patruela. 

"     II              ' 

'         purpurea. 

"       12                    ' 

"        var  limbalis. 

"    13- 

'         formosa  var.  generosa. 

"     14 

'         aneocisconensis. 

"    IS 

'         vulgaris. 

"    i6 

'         repanda. 

"    17. 

"        12.  guttata. 

"    18 

'         hirticollis. 

"    19. 

'         punctulata. 

"20            ' 

'         marginata. 

"    21             ' 

'         puritana. 

"    22            ' 

'         lepida. 

"    23 

'         rufiventris. 

"    24 

'         Hentzii. 

"    25. 

'        tortuosa. 

"    26 

'         abdominalis. 

"    27 

'         marginipennis. 

PLATE 


I  |i   I    I    I 


H 


(  i 


12 


15l 


I 


IG  IT 


20 


22 


23^ 


25 


I'     I 


Beetles 


253 


grubs  (Fig.  342)  which  lie  in  the  mouth  of  a  vertical  burrow  several  inches 
deep,  with  the  dirt-colored  head  bent  at  right  angles  to  the  rest  of  the  body 
and  making  a  neat  plug  for  the  top  of  the  hole.  When  an  unwary  insect 
comes  in  reach  of  this  plug  the  waiting  jaws  make  a  quick  grasp,  and  the 
doomed  prey  is  dragged  down  into  the  darkness.  On  the  fifth  segment 
of  the  abdomen  of  the  larva  there  is  a  hump,  and  on  it  are  two  small  but 
strong  hooks  curved  forward.  "This  is  an  arrangement  by  which  the  little 
rascal  can  hold  back  and  keep  from  being  jerked  out  of  its  hole  when  it  gets 
some  large  insect  by  the  leg,  and  by  which  it  can  drag  its  struggling  prey 
down  into  its  lair,  where  it  may  eat  it  at  leisure.  It  is  interesting  to  thrust 
a  straw  down  into  one  of  these  burrows,  and  then  dig  it  out  with  a  trowel. 
The  chances  are  that  you  will  find  the  indignant  inhabitant  at  the  remote 
end  of  the  burrow  chewing  savagely  at  the  end  of  the  intruding  straw." 

Plate  III  shows  the  appearance  of  the  body  and  the  character  of  the  mark- 
ings of  the  tiger-beetles,  while  the  vivid  color-effects  are  illustrated  in  Plate  11. 
In  the  East  occurs,  besides  Cicindela,  the  genus  Tetracha  (PL  III,  Fig.  i) 
with  two  species;  on  the  plains  of  the  middle  West  the  largest  member  of 
the  family,  Amblychila  cylindriformis,  which  hunts  its  prey  at  twilight,  and 
on  the  Pacific  coast  the  genus  Omus  with  ten  species,  all  nocturnal. 

The  family  Carabidae,  the  predaceous  ground-beetles,  is  a  large  one, 

including  in  North  America  about  1200  species,  representing  over  a  hundred 

genera.     They  are  mostly  dark-colored  and  are  nocturnal  in  habit,  hiding 

by  day  under  stones,  chips,  logs,  etc.,  so  not  many  of  them  are  familiar  or 

even  often  seen.     A  few,  however,  are  large  and  brilliantly  colored,  and 

get  discovered  by  most  collectors.     Like  the  tiger-beetles 

they  are  active  and  predatory,  with  long  strong  mandibles 

and  slender  running  legs.     They  differ  from  the  tiger-beetles 

in    their    dislike  of    daylight,  and   in  having    the  head  in 

most  species  narrower  than   the  thorax.     The  larvae    (Fig. 

343)  are  "mostly  long  flattened  grubs  with  a  body  of  almost 

equal  breadth  throughout.     It  is  usually  protected  on   top 

by  horny  plates  and  ends  in  a  pair  of   conical  and  bristly 

appendages."     Most  of  the  larvtC  burrow  just  beneath  the 

surface  of  the  earth,  feeding  on  various  insects  which  enter 

the  ground  to  pupate  or  for  other  reasons.     They  destroy 

large  numbers  of  the  destructive  leaf- feeding  beetles,  whose        ;  343-— Larva 

°  .  °  '  01  Lalosoma  sp. 

soft-bodied  larvae  leave    the   plants  and    burrow    into   the       (After   Lugger; 

ground  when  ready  to  pupate.     When  full-grown  the  Carabid       enlarged.) 
larvae  form  small  rough  cells  in  the  soil  within  which  they  change  to  pupae. 
When  the  adult  beetles  emerge  they  push  their  way  up  to  the  surface. 

Plate  IV  illustrates  several  species  of  this  family  and  shows  the  charac- 
teristic flattened,  usually  rather  broad    although  trim  and  compact,  shape 


254 


Beetles 


of  the  body.  In  most  of  the  species  the  elytra  are  marked  with  fine  longi- 
tudinal lines  or  rows  of  punctures,  and  in  several  species  the  hind  wings  are 
wanting,  so  that  flight  is  impossible.  There  is  something  characteristic 
and  almost  unmistakable  about  the  general  make-up  and  appearance  of 
these  beetles.  Their  flatness,  and  smoothness,  their  shining  black,  greenish, 
or  brownish  coloration,  and  their  small  head  with  prominent,  projecting, 
slender  antennae,  pointed  mandibles,  conspicuous  clubbed  palpi,  and  bright 
eyes,  together  with  their  equally  characteristic  haunting  of  hidden  places 
on  the  ground,  their  swift  alert  running,  and  readiness  to  bite  when  caught, 
distinguish  them,  almost  at  a  glance,  from  all  other  beetles.  One  of  the 
largest,  most  conspicuous  and  well-known  Carabids  is  the  searcher,  or  cater- 
pillar-hunter, Calosoma  scrutator  (PI.  II,  Fig.  9),  an  inch  and  a  half  long, 
with  vivid  violet-green  elytra  margined  with  reddish.  It  is  commonly  found 
at  twilight  and  after  dark  on  trees,  and  is  often  seen  by  collectors  when 
"sugaring"  for  moths.  It  is  said  to  make  special  war  on  the  hairy  tent- 
caterpillars,  and  thus  do  much  good.  Two  other  species  of  this  genus, 
C.  jrigidum  (Fig.  344)  and  C.  cahduni  (Fig.  345),  the  latter 
called  the  fiery  hunter  from  its  characteristic  rows  of  reddish 
or    copper-colored    punctures    on   the    black   elytra,   are   keen 


Fig.  346. 


Fig.  344.  Fig.  345. 

Fig.   344. — Calosoma  frigidum.     (After  Lugger;     natural   size.) 
•fiG.  345. — Calosoma  calidum.     (After  Lugger;    natural  size.) 
Fig.   346.— Larva  of  Pterostichus  striola.     (After  Schiodte;  two  and  one-half  times  natu- 
ral size.) 


hunters  of  cutworms,  canker-worms,  etc.  At  the  other  extreme  of  size 
in  the  family  are  the  tiny  Bembediums  and  Tachys,  some  species  of 
which  are  but  yV  inch  long.  The  curious  bombardiers,  or  bombarding 
beetles  (Brachina),  when  disturbed,  spurt  out  with  popgun  sound  and  puff 
of  "smoke"  an  ill-smelling,  reddish,  acid  fluid  from  the  tip  of  the 
body.  Comstock  says  that  "these  beetles  have  quite  a  store  of  ammuni- 
tion, for  we  have  often  had  one  pop  at  us  four  or  five  times  in  succession 


AGM^rq 


,ri/j) 


PLATE   IV. 


PREDACEOUS    BEETLES,     (After  Wickham.) 


Fig.    I 

Panagsus  f 

asciatus. 

"         2. 

Patrohus 

longicornis. 

"      3- 

Pterostichus 

rostratus. 

"      4. 

( ( 

honestus. 

"      5- 

( ( 

coracinus. 

"      6. 

<( 

sculptus. 

"      7- 

(( 

lucublandus. 

"      8. 

4t 

tartaricus. 

"      9- 

<C 

mutus. 

"      lO. 

<( 

orinomum. 

'*    II. 

** 

erythropus. 

PLATE  IV 


Beetles 


^S5 


while  we  were  taking  it  prisoner."  These  beetles  have  a  narrow  reddish- 
yellow  head  and  prothorax,  and  blackish-blue  elytra.  Of  similar  appear- 
ance is  Lebia  grandis,  the  enemy  of  the  Colorado  potato-beetle,  feeding 
on  its  egg  and  larvoe.  Most  abundant  of  the  Carabids  are  the  numerous 
dull-black  medium-sized  species  of  Pterostichus  (PI.  IV),  in  which  the  pro- 
thorax  has  a  narrow,  flat,  projecting  margin.  Over  one  hundred  species 
of  this  genus  have  been  found  in  this  country.  Harpalus  is  another  large 
genus  with  some  very  common  species;  H.  pennsylvanicus  is  often  found 
in  orchards  eating  the  larvae  of  the  codlin-moth  and  plum-curculio,  ravag- 
ing fruit-pests.     A  few  Carabids  are  not  such  good  friends,  Lugger  record- 


FiG.  347. — Predaceous  diving-beetles  (and  back-swiramers,  order  Hemiptera)  in  water. 
(From  life;    slightly  less  than  natural  size.) 

ing  the  fact  that  Agonoderus   pallipes,  a    species  abundant  in  Minnesota, 
sometimes  feeds  on  sprouting  seeds  of  corn. 

Predaceous  beetles  of  very  different  habitat  are  the  Dyticidae,  the  carniv- 
orous water-  or  diving-beetles.  Three  hundred  species  occur  in  this  country, 
and  some  members  of  the  family  are  to  be  found  wherever  there  are  streams 
and  ponds.  They  vary  in  size  from  the  large  Cybister  and  Dyticus,  an 
inch  and  a  half  long,  to  small  species  of  Hydroporus  and  other  genera  less 
than  a  fifth  of  an  inch  long,  but  all  are  readily  distinguishable  from  their 
aquatic  companions,  the  whirligigs  (family  Gyrinidae)  (p.  257),  by  having 
but  one  pair  of  eyes,  and  from  the  water-scavenger  beetles  (family  Hydro- 


■y 


Beetl 


es 


philidae)  (p.  258)  by  having  slender  thread-like  antennae  instead  of  clubbed 
ones.  All  are  oval  and  flatly  convex  in  shape,  w^ith  hard  smooth  body-wall, 
usually  brownish  or  black,  and  when  at  rest  hang  head  downward  from 
the  surface  of  the  water,  the  characteristic  breathing  attitude.  The  females 
sometimes  have  the  elytra  furrowed  with  shallow  longitudinal  grooves,  and  the 
males  of  most  species  have  a  curious  clinging-organ  on  the  expanded  first  three 
or  four  tarsal  segments  of  the  front  feet  (Fig.  349).  This  organ  is  com- 
posed of  a  hundred  or  more  small  capsules  on  short  stems  and  two  or  three 
very  much  larger  pads.  It  is  used  for  holding  the  females  in  mating,  and 
adheres  to  their  smooth  body-wall  by  the  secretion  of  a  gummy  fluid  insol- 
uble in  water.  The  pads  and  capsules  may  also  act  to  some  extent  as 
"suckers"  by  atmospheric  pressure.  The  hind  legs  are  long,  strong, 
and  flattened  to  form  oars  or  swimming-organs.  This  beetle  regularly  and 
perfectly  "feathers  its  oars"  by  a  dexterous  twist  while  swimming.  To 
breathe,  the  beetle  comes  to  the  surface — its  body  being  less  dense  than 
water,  it  floats  up  without  effort — and  projects  the  tip  of  its  abdomen  through 
the  surface  film.  It  now  lifts  the  tips  of  the  elytra  slightly;  air  pours  in 
and  is  held  there  by  the  fine  hairs  on  the  back,  where  are  also  the  spiracles, 
or  breathing-openings.  Thus  when  the  beetle  goes  down 
again  it  carries  with  it  a  supply  of  air  by  means  of  which 
respiration  can  go  on  for  some  time  under  water.  The 
diving  beetles  can  be  readily  kept  in  aquaria,  as  can  also 
their  larvag  (described  in  the  next  paragraph),  and  the 
interesting   active    Hfe  with    the  characteristic    swimming, 

diving,  breathing,  captur- 
ing of  prey,  and  feeding 
all  easily  observed. 

The  life-history  of 
no  American  species  has 
been  completely  worked 
out,  but  the  eggs  of  some 
species  are  dropped  ir- 
jv^  regularly  on  the  water, 
while  those  of  others  are 
laid  in  slits  cut  by  the 
sharp  ovipositor  of  the 
female  in  the  stems  of 
aquatic  plants.  The  long, 
slender,  semi-transparent, 
predaceous  larvae  (Fig.  348)  are  known  as  water-tigers.  They  have  six  slender 
legs  and  the  head  is  large  and  flattened.  It  bears  long,  slender,  curved, 
sharp-pointed,  hollow  mandibles,  each  with  a  small  opening  at  the  tip  and 


Fig.  349. 

Fig.  348. — Water-tiger,  the  larva  of  the  predaceous  water- 
beetle,  Dyticus  sp.     (Natural  size.) 

Fig.  34Q. — The  predaceous  water-beetle,  Dyticus  sp.,  pupa 
and  adult.     (Natural  size.) 


Beetles 


257 


another  near  the  base.  When  a  Hve  insect  or  other  aquatic  creature  is  caught 
by  the  active  larva  its  body  is  pierced  by  the  mandibles  and  the  blood  sucked 
through  them  into  the  mouth,  the  opening  at  the  base  just  fitting,  when  the 
mandibles  are  closed,  into  the  corners  of  the  small  silt-like  mouth.  Both 
larvae  and  adults  are  fierce  and  voracious,  and  the  larger  species  attack  and 
kill  small  fish.  In  the  middle  states  these  beetles  actually  do  much  damage 
in  cfarp-ponds.  The  larva  breathes  through  a  pair  of  spiracles  at  the  slender 
tip  of  its  body,  which  is  thrust  up  to  the  air  when  it  comes  to  the  surface 
of  the  water.  When  ready  to  pupate  it  leaves  the  water — breathing  now 
also  through  six  pairs  of  lateral  spiracles — and  makes  a  rough  cell  in  the 
ground  of  the  pond  or  stream  bank.  "The  pupa  state  lasts  about  three 
weeks  in  summer;  but  the  larvae  that  transform  in  autumn  remain  in  the 
pupa  state  all  winter." 

The  larger  of  our  common  species  belong  to  Cybister,  Dyticus,  and 
allied  genera.  In  Cybister  the  little  cups  on  the  under  side  of  the  tarsal 
disks  of  the  male  are  similar,  and  arranged  in  four  rows.  In  Dyticus  and 
its  allies  the  cups  of  the  tarsal  disks  vary  in 
size.  Fig.  349  represents  a  common  species  of 
Dyticus. 

"  The  most  common  of  the  diving-beetles 
that  are  of  medium  size  belong  to  the  genus 
Acilius.  In  this  genus  the  elytra  are  densely 
punctured  with  very  fine  punctures,  and  the 
females  usually  have  four  furrows  in  each  wing- 
cover." 

An  interesting  account  of  the  habits 
and  special  structures  of  the  common  large 
European  diving-beetle,  Dyticus  marginalis, 
is  given  in  Miall's  Natural  History  of  Aquatic 
Insects,  pp.  39-61. 

Smaller  than  the  predaceous  diving-beetles, 
and  readily  recognized  by  their  curious  spin- 
ning or  circling,  in  companies,  on  the  surface 
of  ponds  or  still  pools  in  streams,  are  the 
whirligig-beetles  (Gyrinidffi),  common  all  over 
the  country.  About  forty  species  of  these 
beetles,  varying  in  size  from  one-sixth  to  three-fourths  inch  in  length,  have 
been  found  in  North  America,  three-fourths  of  them  belonging  to  the  genus 
Gyrinus.  They  are  all  of  similar  shape  and  steely  blue-black  in  color, 
and  have  the  compound  eye,  on  each  side,  wholly  divided  into  an  upper 
and  a  lower  part  by  the  sharp  lateral  margin  of  the  head.  Like  the 
Dyticids,  the  whirligig-beetles  breathe  at  the  surface  and  carry  air  down  with 


Fig.  350.  Fig.  351. 

Fig.  350.  —  Whirligig  -  beetle, 
Dineutes  emarginata.  (Twice 
natural  size."! 

Fig.  351. — Larva  of  whirligig- 
beetle,  Gyrinus  marinus. 
(After  Schiodte;   enlarged.) 


258 


Beetl 


es 


them  when  diving  or  swimming  below  the  surface,  by  having  a  bubble 
attached  to  the  posterior  tip  of  the  body.  The  hindmost  legs  are  broad 
and  paddle-shaped,  and  fringed  with  long  stiff  hairs.  The  whirhgig- 
beetles  can  fly,  but  usually  have  to  climb  up  on  some  weed  or  stick  pro- 
jecting from  the  water  in  order  to  make  a  start.  They  can  make  a  curious 
squeaking  noise,  probably  a  call  to  other  whirligigs,  by  rubbing  the  under 
side  of  the  wing-covers  against  the  end  of  the  body.  When  handled,  most  of 
these  beetles  emit  an  ill-smeUing  whitish  hquid. 

In  the  winter  the  whirligigs  lie  torpid  in  mud  among  the  roots  of  water- 
plants,  coming  out  by  twos  and  threes  in  the  spring.  The  eggs  are  laid 
usually  on  the  leaves  of  some  water-plant,  and  the  curious  slender  larva 
(Fig.  351)  is  provided  with  long  tapering  lateral  gills  fringed  with  fine  hairs. 
There  is  a  pair  of  gills  on  each  abdominal  segment.  It  feeds  on  water- 
insects  and  other  small  aquatic  animals,  and  probably  also  on  the  "tender 
parts  of  submerged  plants."  The  pupae  of  but  few  species  are  known. 
That  of  a  common  English  species  lies  in  a  grayish  silken  cocoon  spun  on 
some  water-plant  above  the  water's  surface. 

TRIBE   CLAVICORNIA. 

The  clavicorn  beetles,  or  those  with  clubbed  antennae,  show  much  variety 
in  the  character  of  the  terminal  thickening  of  the  antennae  (Fig.  340,  4-7), 
which  is  the  characteristic  structural  feature  of  the  members  of  the  group, 
and  from  which  the  tribal  name  is  derived.  The  tribe  includes,  too,  beetles 
of  widely  different  habits,  some  aquatic,  others  terrestrial,  some  predaceous, 
others  plant-feeding,  others  living  on  dry  stored  grains,  woolens,  and  still 
others  feeding  on  carrion.  They  have  indeed  little  in  common  and  the 
grouping  is  largely  a  matter  of  convenience  in  classifying.  The  more  im- 
portant families  of  this  tribe  can  be  separated  by  the  following  key: 

Aquatic;  legs  fitted  for  swimming (Water-scavenger  beetles.)     Hydrophilid^. 

Terrestrial;    legs  not  fitted  for  swimming. 

Antennae  moniliform,  i.e.,  with  segments  bead-like;    elytra  usually  covering  only  basal 

half  of  abdomen (Rove-beetles.)     STAPHYLiNiDiE. 

Antennae  moniliform  or  sub-moniliform;   elytra  covering  most  of  the  abdomen:   brown 

or  reddish  species (Grain-beetles,  etc.)     Cucutid^. 

Antennas  capitate,  i.e.,  ending  in  a  little  ball,  or  clavate. 

Large  insects,  the  smaller  not  much  less  than  half  an  inch  long  (except  Catops); 

body  usually   flattened (Carrion-  or   burying-beetles.)     Silphid^. 

Small  insects,  mostly  less  than  one-half  inch  long;    body  thick  and  convex  above. 

(Larder-beetles,  etc.)     Dermestid^. 

In  the  same  ponds  and  pools  with  the  predaceous  diving-beetles  and 
whirligigs  may  be  found  other  water-beetles,  black,  shining,  and  often  of 
large  size,  which  are  readily  distinguished  by  their  short  concealed  clavate 


Beetles 


259 


antennae  (the  long  slender  palpi  may  be  at  first  glance  mistakenly  taken 
for  antennae)  as  members  of  the  family  Hydrophilidce,  the  water-scavenger 
beetles.  As  the  popular  name  indicates,  these  beetles  feed,  for  the  most 
part,  on  decaying  material,  animal  or  plant,  found  in  the  water,  although 
they  feed  also  on  Uving  water-plants,  as  Nitella;  and  living  insects  are  cer- 
tainly taken  by  some  species.  They  can  be  distinguished  from  the  Dyticida) 
when  swimming  by  their  use  of  the  oar-legs  alternately,  and  when  at  the 
surface  getting  air  by  hanging  there  head  upward.  The  air  spreads  in  a 
thin  silvery  layer  over  the  ventral  side  of  the  body,  held  there  by  fine  pubes- 
cence. 

The  eggs  are  deposited  in  a  ball-like  silken  cocoon  with  a  curious  handle- 
like tapering  curved  stem  or  spike  (Fig.  353).  The  cocoon  floats  freely 
on  the  water,  or  is  attached  to  some  floating  leaf  or  grass-blade  or  stem. 
From  fifty  to  a  hundred  eggs  are  enclosed  in  each  sac.  The  larvae  (Fig. 
354)  are  elongate,  but  thicker  and  less  graceful  than 
the  water-tigers  (larvae  of  the  Dyticidae),  and,  unlike 
the  adults,  feed   chiefly  on  living  insects,  snails,  tad- 


Fig.  352.  Fig.  353.  Fig.  354. 

Fig.   352.^Great  water-scavenger  beetle,  Hydrophilus  triangularis.     (Natural  size.) 
Fig.  353. — Egg-case  of  great  water-scavenger   beetle,  Hydrophilus  sp.     (Twice  natural 

size.) 
Fig.    354. — Larva    of    great    water-scavenger    beetle,    Hydrophilus    caraboides.      (After 

Schiodte;  natural  size.) 


poles,  etc.  They  breathe  through  spiracles  at  the  tip  of  the  body,  coming 
occasionally  to  the  surface  to  get  air.  In  shallow  water  they  simply  lie 
with  the  tip  of  the  tail  projected  up  to  the  surface.  When  ready  to  pupate 
the  larvae  leave  the  water,  and,  burrowing  a  few  inches  into  the  ground,  form 
a  rough  cell  in  which  they  transform.  The  adult  beetles  fly  readily,  and 
sometimes,  with  Dyticids,  are  to  be  found  at  night  around  electric  lights. 
When  winter  comes  they  burrow  into  the  bottom  or  bank  of  the  pond  or 
stream  and  lie  torpid  until  spring. 


26o 


iJeetles 


About  one  hundred  and  fifty  species  of  HydrophilidEe  are  known  in  this 
country.  The  largest  species  belong  to  the  genus  Hydrophilus,  are  shining 
bluish  or  greenish  black,  and  measure  nearly  two  inches  in  length.  "In  the 
genus  Hydrocharis  the  metasternum  is  prolonged  somewhat,  but  does  not 
form  a  long,  sharp  spine  as  in  Hydrophilus  and  Tropisternus,  and  the  sternum 
of  the  prothorax  bears  a  keel-shaped  projection.  Our  most  common  species 
is  Hydrocharis  obtusatus;  this  measures  about  five-eighths  of  an  inch  in 
length. 

"  Some  of  the  smaller  species  of  this  family  are  not  aquatic,  but  live  in 
moist  earth  and  in  the  dung  of  cattle,  where,  it  is  said,  they  feed  on  dipterous 
larvae." 

The  rove-beetles,  Staphylinidae,  form  a  large  family,  numerous  in  species 
and  individuals  over  the  whole  country,  and  one  whose  members  are  readily 
recognized  by  the  elongate  flattened  soft  body,  narrow  and  parallel  sides, 
with  short  truncate  leathery  elytra  under  which  the  hind 
wings  are  compactly  folded  so  as  to  be  wholly  concealed. 
They  are  mostly  carrion-feeders  and  with  the  Silphidae 
(p.  261)  are  almost  sure  to  be  found  whenever  a  mass  of 
decaying  flesh  or  e.xcrementitious  matter  exposed  on  the 
ground  is  turned  over.  They  run  swiftly  when  disturbed 
and  curve  the  tip  of  the  flexible  abdomen  up  over  the 
body  in  a  sort  of  threatening  way,  as  if  they  would  sting. 
They  cannot;  they  can  simply  smell  bad.  Although  the 
more  famihar  rove-beetles  are  of  fair  size,  from  half  an 
inch  to  nearly  an  inch  long,  the  majority  of  the  one 
thousand  or  more  species  found  in  this  country — 9000 
species  are  known  in  the  world — are  very  small.  In 
California  great  swarms  of  minute  rove-beetles  dance  in 
the  air  in  April  and  May,  and  are  a  woful  nuisance  to 
people  driving  or  bicycling.  They  get  into  one's  eyes, 
and  when  crushed  by  rubbing,  their  acrid  body-fluids 
both  smell  bad  and  burn.  Among  these  smaller  Sta- 
phylinids  are  numerous  predaceous  species  and  many  which  are  found  in 
flowers,  probably  feeding  on  pollen.  Others  are  found  on  fungi,  on  mud, 
and  in    other  damp   places,  and    some    live  in    ants'    nests    (see    Chapter 

XV,  p.  55^)- 

The  larvae  (Fig.  355)  are  found  in  the  same  places  as  the  adults,  and 
are  elongate,  narrow-bodied,  and  rather  like  those  of  the  Carabidae,  but 
each  foot  has  but  a  single  claw.  The  pupse  of  some  species  are  enclosed 
in  a  sort  of  exudation  that  dries  into  a  firm  protecting  coating  rather  like 
the  horny  cuticle  of  a  lepidopterous  chrysahd. 

Among  the  more  familiar  rove-beetles  are  species  of  the  genus  Creophilus. 


Fig.  355.  —  Larva 
of  a  rove-beetle, 
X  anthaliniis 
lentus.  (After 
Schiodte;  twice 
natural  size.) 


Beetles 


261 


Fig.  356. — Rove-bee- 
tle, Creophilus  vil- 
losus.  (One  and  one- 
half  times  natural 
size.) 


C.  villosus  (Fig.  356),  common  all  over  the  country,  is  about  |  inch  long, 

blackish,  with  an  incomplete  broad  transverse  patch  of  yellowish-gray  hairs 

across  the  elytra  and  another  on  the  second  and  third  abdominal  segments. 

Leistotrophus  is  a  genus  with  but  one  American  species,  L.  cingulatus,  about 

same  size  as  the  preceding,  but  of  grayish-brown  color 

indistinctly  spotted  with  brown  and  with  a  golden  tinge 

on  the  tip  of  the  abdomen.     Staphylinus  is  a  genus  of 

twenty  species  or  more;    5.  maculosus,  i  inch  long,  is 

dark  cinnamon-brown  with    a  row  of    squarish    black 

spots    along    the    middle  of    the  abdomen;    S.   cinna- 

mopterus,     J    inch    long,    is     cinnamon-colored,    with 

blackish  abdomen ;    S.  lonientosus,  \  inch  long,  is  deep 

dull  black;    5.  violaceiis,  \    inch    long,    is   black  with 

thorax  and  elytra  violet.     Not  uncommon  along  sandy 

seashore  in  CaHfornia  is  a  curious  light-brown  wing- 
less   rove-beetle,   Thinopimis    picius,   with    very    short 

elytra,  each  with  an  open  black  ring,  and  with  a  double  row  of  small  black 

dots  on  the  abdomen.     Its  abdomen  is  short  and  rather  broad 

Another  family  of  carrion-beetles  of  comparatively  few  species,  some  of 

which,  however,  are  familiar  and  widely  distributed,  is  that  of  the  Silphidae, 

or  burying-beetles.  Both  adults  and  larvae 
feed  almost  exclusively  on  decaying  flesh. 
The  antennae  of  most  species  have  the  last 
four  or  five  segments  expanded  and  fused 
so  as  to  form  a  conspicuous  little  ball  or  a 
compact  club.  Two  genera  include  most 
o  the  familiar  species,  although  the  one 
hundred  North  American  species  of  the 
family  represent  thirty  different  genera. 
These  two  are  Silpha  (Fig.  357),  the  roving 
carrion-beetles,  and  Necrophorus  (Fig. 
358),  the  burying-beetles.  The  charac- 
teristic shape  and  appearance  of  these  two 
types  are  well  shown  in  the  figures.  The 
species  of  Silpha  are  short,  broad-bodied, 
flat,  dull  blackish,  and  with  the  elytra  rather 

leathery  than  horny,  and   lined   longitudinally  with   shallow   grooves.     The 

prothorax  is  subcircular,  with  thin  projecting  margins.  The  larvce  (Fig. 
359)  and  adults  are  found  in  and  underneath  putrid  flesh.  The  larvae 
are  apparently  more  active  than  the  adults.  Silpha  lapponica,  a  common 
dull  black  form  in  both  Europe  and  America,  is  said  to  enter  houses  in  Lap- 
land to  eat  the  stores  of  animal  provisions.    S.  americana  (PI.  II,  Fig.  5)  has 


Fig.  357.  Fig.  358. 

Fig.  357.  —  Carrion-beetle,  Silpha 
noveboracensis.  (One  and  one-half 
times  natural  size.) 

Fig.  358. — Burying-beetle,  Necropho- 
rus marginatus.  (One  and  one- 
half  times  natural  size.) 


262 


Beetles 


Fig.  359.  —  Larva 
of  can  ion-beetle, 
Silpha  sp.     (One 


the  large   shield-like   prothorax  yellowish  with  a  black  blotch  in  the  center. 

In  S.  noveboracensis  only  the  margin  of  the  prothorax  is  yellow. 

The    burying-beetles,    Necrophorus,    are    large    insects    from    an    inch 

to  an  inch  and  a  half  long,  with  the  body  thick  and  parallel-sided.      The 

commoner  species  have  a  pair  of  dull  red  transverse  blotches  on  each  elytron. 
In  some  species  the  prothorax  and  head  are  also  marked 
with  red.  The  common  name  comes  from  the  well- 
known  habit  of  these  insects  of  digging  underneath  small 
dead  animals,  as  mice  or  birds,  until  the  corpse  is  in  a 
hole;  it  is  then  covered  over  and  thus  really  buried. 
The  female  lays  her  eggs  on  the  corpse,  and  the  larvae 
hatching  from  them  feed  on  the  decaying  matter.  These 
larvae  have  spiny  plates  on  the  back  of  the  body  and 
are  otherwise  unlike  the  Silpha  larvae.     Some  Necrophorus 

and  one-half  times    larvae  are  predaceous  and  others  feed  on  decaying  vege- 
natural  size.)  ^^^^^  j^^^^^^ 

Most  of  the  blind,  pale  cave-beetles  found  in  caves  in  this  country  and 
Europe  are  Silphidas. 

The  Cucujidae,  with  a  name  derived  from  the  Portuguese  Cucuyo,  a 
large  luminous  Brazilian  snapping-beetle  or  elater,  of  entirely  different 
family,  are  a  family  of  small  beetles,  with  flattened  reddish  or  light-brown 
body,  whose  outdoors  haunts  are  mostly  under  the  bark  of  trees.  Sev- 
eral species,  however,  have  learned  that 
life  in  a  granary  is  just  as  safe  from  pre- 
daceous enemies,  and  a  thousand  times 
safer  from  starvation.  Of  these  sophisticated 
Cucujids,  Silvanus  surinamensis,  the  saw- 
toothed  grain-beetle  (Fig.  360),  is  the  most 
familiar  and  injurious.  The  adult  is  about 
^  inch  long,  flat  and  chocolate-brown,  and 
may  be  distinguished  from  the  other  small 
beetles  similarly  attacking  stored  grain  by 
the  serrated  margins  of  its  prothorax.  It 
infests  dried  fruits,  nuts,  .seeds,  and  dry 
pantry  stores  of  all  sorts,  as  well  as  grain  bins 
and  cribs.  The  larvae  (Fig.  360)  are  active 
little  six-legged  flattened  whitish  grubs  which  run  about  and  nibble  indus- 
triously. When  full-grown  the  larva  attaches  itself  by  a  gummy  excretion 
to  some  object,  and  pupates.  When  living  in  light  granular  substances, 
as  oatmeal,  etc.,  a  delicate  case  is  constructed  of  the  material  in  which  to 
pupate.  In  summer  the  life-cycle  from  egg  to  adult  requires  but  twenty- 
four  days;    in  spring  from  six  to  ten  weeks.     Six  to  seven  generations  are 


Fig.  360. — Larva,  pupa,  and  adult  of 
the  saw-toothed  grain-beetle,  Sil- 
vanus surinamensis.  (After  How- 
ard and  Marlatt;  much  enlarged.) 


Beetles 


263 


produced  annually  in  the  latitude  of  Washington.  The  insect  here  hiber- 
nates in  the  adult  state. 

The  largest  and  most  familiar  of  the  outdoor  Cucujids  is  a  very  flat 
bright-red  species,  Cucujus  flavipes  (PI.  II,  Fig.  11),  about  half  an  inch 
long,  with  black  eyes  and  antennae  and  the  legs  with  dark  tibiae  and  feet. 

The  Dermestidac  constitute  only  a  small  family  of  forty  or  more  North 
American  species  representing  twelve  genera,  but  one  which  nevertheless 
is  of  unusual  interest  and  importance  to  entomologists,  for  to  this  family 
belong  those  insects  which  eat  entomological  collections.  A  depraved  taste, 
but  one  which  causes  almost  constant  anxiety  and  occasional  serious 
discouragement  on  the  part  of  the  industrious  collector.  Dermestids 
are  not  the  bane  of  collectors  and  museum  curators  alone,  as  larder-beetles, 
"buffalo-moths,"  and  carpet-beetles,  various  species  of  this  family,  help 
make  life  a  burden  to  the  housewife. 

All  of  the  Dermestidae  are  small,  oval,  and  plump-bodied,  the  largest 
species  being  about  ^  inch  long,  and  most  of  them  are  covered  with  small 
scales,  which  give  them  their  rather  varied  colors  and  markings.  The  beetles 
themselves  mostly  feed  on  pollen,  but  come  into  houses  to  deposit  their  eggs. 
From  the  eggs  hatch  soft-bodied  little  grubs  thickly  covered  with  hairs, 
often  very  long  (Figs.  361  and  362).     These  larvae  are  the  real  pests  of  house- 


FiG.  361.  Fig.  362. 

Fig.   361. — Carpet-beetle   or  "buffalo-moth,"  Anthrenns  scrophularia,  larva  and  adult. 

(After  Howard  and  Marlatt;    much  enlarged.) 
Fig.    362. — Black   carpet-beetle,    Attagenus   piceits,   larva   and   adult.     (After   Howard 

and  Marlatt;    enlarged.) 


hold  and  museum:  they  feed  industriously  on  dried  insect  specimens, 
stuffed  birds  and  mammals,  woolen  carpets,  furs,  feathers,  or  on  meat  and 
cheese  (depending  on  the  particular  habits  of  the  various  species)  until  full- 
grown.  Then  they  crawl  into  a  crack  or  hide  in  the  body  of  a  museum 
specimen  and  pupate  within  the  larval  cuticle,  which  serves  as  a  sort  of  thin 
hairy  protecting  shell. 

The  usual  museum  pests  are  two  species,  A.  varius  and  A.  museorum,  of 
the  genus  Anthrenus.  The  adult  beetles  are  tiny,  broadly  oval,  very  convex, 
with  the  black  body  covered  above  with  scales  some  of  which  are  yellowish 


264 


Beetles 


and  some  whitish  and  so  arranged  as  to  give  the  back  an  irregularly  spotted 
appearance.  The  hairy  larvae  burrow  into  the  specimens  and  nibble  away 
at  the  dry  bodies.  Their  presence  may  be  detected  by  a  little  pile  of  dust 
under  the  pinned-up  specimen  and  by  the  falling  off  of  its  legs,  head,  etc. 
Pour  a  teaspoonful  of  carbon  bisulphide  into  a  corner  of  the  case  and 
keep  it  tightly  shut  for  a  day.  The  fumes  of  the  CSj  are  fatal  to  the  pests. 
The  carpet-beetle  or  "  buffalo-moth "  (Fig.  361)  is  another  species,  A.  scrophu- 
laricE,  of  this  same  genus.  The  beetle  is  about  y\  inch  long,  marbled  black 
and  white  above  with  a  central  reddish  line  bearing  short  lateral  offshoots 
on  each  side.  The  larva  is  thick,  soft,  active,  and  covered  with  stiff  brown 
hairs.  It  feeds  voraciously  on  carpets,  working  on  the  under  side,  and 
usually  making  long  slits  following  the  fioor-cracks.  The  beetles  are  common 
outdoors  on  plants  of  the  family  Scrophulariaceae,  but  come  indoors  to  lay 
their  eggs.  The  remedy  for  the  carpet-beetle  is  to  use  rugs  instead  of 
carpets,  and  to  lift  and  shake  these  rugs  often.  Another  member  of  this 
family  attacking  carpets  is  the  black  carpet-beetle,  Attagenus  piceus  (Fig. 
362).  The  beetle  is  black,  and  the  larva  is  longer,  more  slender,  and  lighter 
brown  than  the  buffalo-moth,  and  has  a  conspicuous  pencil  or  tuft  of  long 
hairs  at  the  posterior  tip  of  the  body.     The  larder-  or  bacon-beetle,  Dermestes 

lardarius  (Fig.  363),  is  about  l^  inch 
long,  dark  brown  with  a  pale-yellowish 
band,  containing  six  black  dots  across 
the  upper  half  of  the  wing-covers. 
The  larva  is  elongate,  sparsely  hairy, 


(After 


Fig.  363.  Fig.  364. 

Fig.  363. — The    larder-beetle,  Dermestes    lardarius,    larva,    pupa,    and    adult. 

Howard  and  Marlatt;    much  enlarged.) 
Fig.   364. — Larva    of  a  water-penny  beetle    of    the    Parnidce.      (Four   times    natural 

size.) 


brown,  and  has  two  short  curved  spines  on  top  of  the  last  body-segment. 
It  feeds  on  many  kinds  of  animal  substance,  as  ham,  bacon,  old  cheese, 
hoofs,  horn,  skin,  beeswax,  feathers,  hair,  and  also  attacks  museum  specimens. 
Another  family  of  Clavicornia  which  possesses  a  special  interest  is  the 
Parnidae,  or  "water-pennies,"  a  family  of  forty  species  representing  ten  genera 
of  small  brown  robust-bodied  insects  which  live  in  water  and  yet  do  not 


Beetles  265 

have  their  legs  fitted  for  swimming,  nor  in  any  other  way  the  body  partic- 
ularly modified  for  an  aquatic  life.  They  crawl  around  on  submerged  stones, 
sticks,  and  water-plants,  carrying  a  supply  of  air  with  them,  held  by  the 
fine  pubescence  of  the  body.  The  larvae  are  curiously  flattened,  broadly 
oval  to  nearly  circular  small  creatures  (Fig.  364),  which  cHng  to  stones  and 
give  the  family  its  popular  name  of  "water-pennies."  As  the  legs,  mouth- 
parts,  eyes,  etc.,  are  all  on  the  under  side  and  concealed,  the  flat,  brownish, 
leathery  little  "penny"  is  usually  not  recognized  as  an  insect  by  the  observer 
of  brook  life. 

The  family  Platypsyllidae  has  been  estabhshed  to  include  a  single 
species  of  strangely  shaped  beetle  which  lives  as  a  parasite  on  the  bodies 
of  beavers.  Its  name  is  Platypsylla  castoris;  it  is  about  ^-g-  inch  long,  blind 
and  wingless,  and  with  the  elytra  rudimentary.  This  degenerate  condition 
of  the  body  is  due  of  course  to  the  parasitic  habit.  Other  obscure  httle 
beetles  of  curious  habits  are  the  Pselaphidae  and  Scydmaenidse,  many  of 
which  live  commensally  with  ants  in  their  nests.  These  beetles  are  rarely 
over  an  eighth  of  an  inch  long,  and  some  of  them  have  bodies  strangely 
modified  to  look  like  ants.  (For  a  further  account  of  these  insects  see 
the  discussion  of  myrmecophily  in  Chapter  XV.) 

TRIBE    SERRICORNIA. 

In  this  tribe  of  beetles,  characterized  by  having  the  antennae  slender, 
with  each  segment  projecting  more  or  less  inward  so  as  to  give  the  whole 
antennae  a  saw-toothed  or  serrate  character  (Fig.  340,  10),  are  included  sev- 
eral families  certainly  not  closely  related  and  having  widely  different  habits 
and  appearance.  The  serrate  character  of  the  antennae,  too,  is  sometimes 
so  slight  that  it  can  hardly  be  distinguished  with  certainty.  The  more 
important  families  of  the  tribe  can  b:  separated  by  the  following  key: 

Head  inserted  in  thorax  as  far  as  the  eyes;  body  elongate  or  elhptical,  and  with  unusually 
hard  cuticle. 
Antennae  finely  serrate,  the  first  two  abdominal  segments  grown  together  on  the  ven- 
tral side (Metallic  wood-borers.)     Buprestid^e. 

Antennee   often   filiform;     first   two   abdominal   segments   free. 

(Chck-beetles.)     Elaterid^. 
Head  free,  but  bent  under  the  thorax. 

Small  insects  usually  less  than  \  inch  long (Death-watch  beetles.)     Pjinid.^. 

Head  free,  but  often  partly  or  wholly  covered  by  the  thin  anterior  margin  of  the  thorax. 
Wing-covers  flexible;    body  elongate  and  flattened;    antennae  not  enlarged  at  tip. 

(Fireflies.)     Lampyrid.e. 

Wing-covers  firm,  thorax  convex,  body  not  much  flattened;    antennae  often  enlarged 

at  tip (Checkered  beetles.)     Clerid^. 

The  metallic  wood-borers,  or  flat-headed  borers,  a  name  suggested  by 
the  flat  broad  head  of  the  larva,  constitute  the  large  and  important  family 


266 


Beetles 


Fig.  365.— a  flat- 
headed  borer, 
larva  of  Rha- 
gium  lineatum. 
(Natural  size.) 


Buprestidse,  of  which  over  two  hundred  species  occur  in  North  America. 
The  adult  beedes  have  an  elongate  body,  trim  and  compact,  with  a  rigid 
and  armor-plate-hke  cuticle,  and  have  iridescent  metallic  coloring.  Green, 
violet,  reddish,  blue,  copper,  golden  they  may  be,  always  shining  like 
burnished  metal  and  the  whole  body  looking  as  if  cast  in  bronze.  The 
antennae  are  short  and  serrate  on  the  inner  margin,  the  head  deeply  inserted 
in  the  thorax,  and  the  latter  fitting  closely  against  the 
abdomen  and  wing-covers;  and  the  second  and  third 
abdominal  segments  are  rigidly  fused.  These  beetles  are 
diurnal,  running  actively  on  tree-trunks  or  resting  on 
flowers;  seeming  to  delight  in  the  warm  bright  sunlight, 
in  which  their  resplendent  colors  flash  and  glance  Hke 
jewels. 

The  larvae  are  mostly  wood-borers,  although  those  of 
some  of  the  smaller  species  mine  in  leaves  or  live  in  galls. 
The  wood-boring  Buprestid  larvae  are  characterized  by  the 
strangely  enlarged  and  flattened,  legless,  first  thoracic 
segment,  on  which  the  small  head  with  its  powerful  jaws 
sets  in  front,  and  the  tapering,  flattened,  legless,  meso- 
and  meta-thoracic  segments  behind.  The  abdomen  is 
elongate  and  rather  narrow,  the  segments  showing  dis- 
tinctly. The  whole  larva  (Fig.  365)  is  thus  a  footless  whitish  tadpole-like 
grub,  expressively  known  as  a  flat-headed  or  hammer-headed  borer.  The 
larvs  that  do  not  burrow  in  wood  are  cylindrical  and  have  three  pairs  of  legs. 
The  most  injurious  Buprestid  is  the  notorious  flat-headed  apple-tree 
borer,  Chrysohothris  femoraia  (Fig.  366),  an  obscure  bronze  or  greenish- 
black  beetle  about  half  an  inch  long.  The  legs  and 
under  side  of  the  body  are  of  burnished  copper,  and 
the  antennae  green.  The  eggs  are  glued  to  the  bark 
under  scales  or  in  cracks;  the  young  larva  on  hatching 
eats  inward  through  the  bark  to  the  sapwood  and 
there  burrows  about,  sometimes  quite  girdling  the  tree. 
Later  it  bores  into  the  solid  heart-wood,  working  up- 
ward and  then  again  out  into  the  bark,  where  it  forms 
a  cell  in  which  it  pupates,  issuing  as  an  adult  in  just 
about  one  year  from  the  time  of  its  hatching.  This 
pest  attacks  peach-  and  plum-trees  and  several  forest- 
and  shade-trees  as  well  as  the  apple-tree.  It  ranges 
over  the  whole  country.  To  prevent  the  egg-laying  on  the  bark,  the  lower 
trunk  of  the  tree  should  be  washed  with  fish-oil  soap  during  June  and  July. 
When  borers  are  once  in  the  tree,  cutting  them  out  is  the  only  remedy. 
The  genus  Agrilus  contains  a  number  of  species  having  the  head  flatly 


Fig.  366.  —  Apple-tree 
borer,  Chrysohothns 
femorata.  (Twice 
natural  size.) 


Beetles     ■  267 

truncate  in  front,  as  if  cut  sharply  off,  and  the  body  rather  cyhndrical  than 
flattened,  as  with  most  other  Buprestids.  A.  ruficollis,  the  red-necked  black- 
berry-borer, y%-  inch  long,  with  dark  bronze  head,  coppery  bronze  prothorax, 
and  black  wing-covers,  has  a  larva  that  bores  into  the  canes  of  blackberries  and 
raspberries,  burrowing  spirally  about  in  the  sapwood  until  full-grown,  when 
it  bores  to  the  pith  and  there  pupates.  The  eggs  are  laid  in  June  and  July 
on  the  young  canes.  Infested  canes  often  show  gall-like  swellings,  and 
should  be  cut  off  and  burned. 

Our  largest  Buprestids  belong  to  the  genus  Chalcophora.  C.  virginiensis 
■  is  an  inch  long,  dark  coppery  or  blackish  with  elevated  lines  and  depressed 
spots  on  the  elytra.  The  larvae  bore  into  pines.  C.liherta  (PI.  II,  Fig.  3)  is 
a  beautiful  pink  bronze  with  darker  raised  lines.  Dicerca  divaricata,  f  inch 
long,  is  copper-colored,  with  the  black-dotted  elytra  tapering  behind  and 
separated  at  the  tips.  Buprestis  (PI.  II,  Fig.  8)  is  a  genus  of  rather  large 
brassy-green  or  brassy-black  species  often  spotted  with  yellow  on  the  elytra 
and  beneath. 

Resembling  the  Buprestids  much  in  general  shape  and  appearance,  the 
click-beetles,  Elateridae,  are  readily  distinguished  from  them  by  their  lack 
of  metaUic  colors,  the  backward-projecting,  sharp-pointed  hinder  angles 
of  the  prothorax,  and  their  curious  capacity,  whence 
their  name,  of  springing  into  the  air  with  a  sharp  click 
when  laid  back  downward.  When  a  click-beetle — 
snapping-bugs  and  skipjacks  are  other  common  names 
for  them — is  disturbed  it  falls  to  the  ground,  lying 
there  for  a  little  while  as  if  dead.  Then  if  it  has 
alighted,  as  it  usually  does,  on  its  back,  it  suddenly 
gives  a  spasmodic  jerk  which  throws  it  several  inches 
high  and  brings  it  down  right  side  up.  This  springing 
is  accomplished  by  means  of  an  apparatus  consisting 
of  a  small  cavity  on  the  under  side  of  the  mesothorax  ^^'^-  367-  —  Ventral 
into  which  the  point  of  a  curved  projecting  process  click-beetle  show- 
from  the  prosternum  fits  (Fig.  367).  When  the  beetle  is  ing  snapping  appa- 
laid  on  its  back  it  bends  in  such  a  way  as  to  bring  the       sLe")'  ^  "^a 

tip  of  the  curved  horn  to  the  edge  of  the  cavity,  when, 
by  a  sudden  release  of  muscular  tension  this  tip  slips  and  the  insect  is 
thrown  into  the  air.  The  Elateridae  are  a  large  family,  about  350  species 
being  known  in  this  country.  They  are  mostly  of  small  or  medium  size, 
although  some  are  an  inch  or  more  long;  a  very  few  reach  a  length  of 
nearly  two  inches.  As  a  rule  they  are  uniform  brownish;  some  blackish 
or  grayish  and  others  banded  and  marked  with  brighter  colors.  In  the 
South  occur  certain  luminous  click-beetles.  In  Cuba  ladies  sometimes  use 
these   phosporescent    species,  which   are   large  and   emit  a   strong  greenish 


268 


Beetles 


light,  as  ornaments,  by  keeping  them  aUve  in  h'ttle  lace  pockets  on  their 
gowns  or  attached  to  delicate  golden  chains.  Two  large  eye-like  spots  on 
the  prothorax,  and  the  under  side  of  the  hinder  part  of  the  abdomen,  are 
the  luminous  regions. 

The  larvae  (Fig.  368)  are  elongate,  slender,  horny-skinned,  brownish 
or  yellowish  white,  living  in  the  ground  or  in  decaying  wood,  and  popularly 
and  aptly  known  as  wireworms.  They  have  three  pairs  of  short  legs,  and 
a  stumpy  process  on  the  last  segment  of  the  body.  They  feed  on  the  seeds, 
roots,  and  other  underground  parts  of  plants  and  do  much  damage  to  various 
crops.  Often  whole  fields  of  grain  are  ruined  by  the  attack  of  wireworms 
on  the  planted  seeds;    meadows  often  suffer  severely,  and  strawberries  lose 

their  stolons.  The  beetles  fly  about 
in  early  summer,  depositing  their 
eggs  in  the  ground  in  grassy,  weedy, 
or  plowed  land.  The  larvae  soon 
hatch,  dig  down  into  the  soil,  and  feed 
on  roots  and  seeds  for  two  or  three 
years,  when  they  become  full-grown. 
They  pupate  in  the  ground  in  early 
fall  and  the  pupae  transform  to  adults 
before  winter,  but  the  beetles  do  not 
issue  from  the  ground  until  the  fol- 
lowing spring. 

Among  our  largest  click-beetles 
is  the  eyed  elater,  Alaus  oculatus 
(Fig.  369),  if  inch  long,  blackish 
with  large  uneven  whitish  gray  dots, 
a  pepper-and-salt  fellow,  Comstock 
well  calls  him,  with  a  pair  of  large 
white-rimmed  velvet-black  eye-spots 
on  the  prothorax.  The  large  larvae,  about  2  inches  long,  live  in  decaying 
wood  and  are  often  found  in  the  trunks  of  old  apple-trees.  Elaier  rubricollis, 
i  inch  long,  is  black  with  light-red  prothorax;  E.  sangmnipennis, 
j\  inch  long,  is  black  with  light-red  elytra;  E.  nigricollis,  f  inch  long,  is 
black  with  whitish  elytra.  Athoics  scapidaris,  f  inch  long,  is  green  sh 
black  with  the  base  of  the  elytra  and  the  hind  points  of  the  prothorax  clay- 
yellow.  Several  species  of  Corymbetes  have  the  elytra  brownish  yellow  with 
transverse  zigzag  black  bands;  C.  hieroglyphicus,  i  inch  long,  has  two 
bands;  C.  hamaius,  rather  smaller,  has  one  band  near  the  tip.  Melanactes 
piceus,  I  inch  long,  is  glossy  black  and  its  large  larva  is  luminous, 
strong  green  light  being  emitted  from  a  narrow  transverse  region  with 
expanded  ends  on  each  segment. 


Fig.  368.  Fig.  369. 

Fig.    368. — Larva  of  a  click-beetle,  Elater 

acerrimus.       (After    Schiodte;     natural 

size.) 
Fig.  369. — An  eyed  elater,  Alans  oculatus. 

(One  and  one-half  times  natural  size.) 


Beetles 


269 


The  fireflies  are  familiar  insects  which  are  not  flies  but  beetles,  although 
their  soft  body  and  flexible  leathery  wing-covers  are  not  of  the  typical 
coleopterous  type.  The  nocturnal  fireflies  and  their  diurnal  first  cousins, 
the  soldier-beetles,  compose  a  coleopterous  family,  Lampyrida',  of  con- 
siderable size  and  common  distribution  over  the  whole  world.  The  "glow- 
worm" of  England  and  Europe  is  the  wingless  female  of  a  common  firefly, 
and  the  railway-beetle  of  Paraguay,  a  worm-hke  creature  3  inches  long, 
that  emits  a  strong  red  light  from  each  end  of  the  body  and  a  green  light 
from  points  along  the  sides,  is  also  probably  the  wingless  female  of  a  large 
firefly  species.  In  this  country  over  200  species  of  Lampyridae  have  been 
'Ound.  Comparatively  few  of  them,  however,  are  luminous.  The  light- 
giving  organ  is  usually  situated  just  inside  of  the  ventral  wall  of  the  last  seg- 
ments of  the  abdomen,  and  consists  of  a  special  mass  of  adipose  tissue  richly 
supplied  with  air-tubes  (tracheae)  and  nerves.  From  a  stimulus  conveyed 
by  these  special  nerves  oxygen  brought  by  the  network  of  tracheae  is  released 
to  unite  with  some  substance  of  the  adipose  tissue,  a  slow  combustion  thus 
taking  place.  To  this  the  light  is  due,  and  the  relation  of  the  intensity  or 
amount  of  light  to  the  amount  of  matter  used  up  to  produce  it  is  the  most 
nearly  perfect  known  to  physicists. 
Not  only  are  the  adult  fireflies 
luminous,  but  in  some  species  the 
pupae  and  larvae  and  even  the 
eggs  emit  light.  The  combustion 
in  the  egg  is  of  course  accom- 
plished wholly  without  tracheae 
or  controlling  nerves. 

The  larvae  (Fig.  370)  of  Lam- 

pyrida;     mostly     burrow     under-     Fig.  370.  Fig.  371.  Fig.  372. 

ground,  where  they  feed   on   soft-  ^'?-  37o.— Larva  of  firefly,  Photinus  modestus. 
,  .  (Twice   natural  size.) 

bodied    msects,    slugs,    and    oXhtr  Yig.   7,-ji.~Tue^y,  Photinus  scintiUans.    (Three 
similar    food.      The    adults,    too,       times  natural  size.) 

,1       r  1  r  Fig.  372. — Checker-beetle,     Trichodes   ornatus 

are  carnivorous,  the  diurnal  forms,      (Twice  natural  size.) 

called  soldier-beetles,  being  com- 
monly seen  on  flowers  or  tree-trunks  hunting  prey. 

The  commoner  luminescent  fireflies,  or  "lightning-bugs,"  belong  to  the 
genus  Photinus.  P.  pyralis,  the  common  species  from  Illinois  south,  is 
^  inch  long,  blackish,  with  prothorax  with  red  disk,  yellow  margin,  and  black 
spot  in  center,  and  the  elytra  with  narrow  yellowish  border.  Farther  north 
and  east  the  commonest  species  is  P.  scintiUans  (Fig.  371),  similar  in  mark- 
ing but  smaller.  P.  angulatus,  h  inch  long,  is  pale,  with  wide  yellow  margins 
on  elytra  and  the  margin  of  the  prothorax  clouded  with  black.  The  com- 
moner soldier-beetles   belong    to  the  genus  Chauliognathus,  which  is  char- 


270 


Beetles 


acterized  by  the  possession  of  a  pair  of  extended  fleshy  processes  belonging 
to  the  maxilla,  which  are  used  in  lapping  up  flower-nectar  and  pollen.  Two 
common  species  in  the  East  are  C.  pennsylv aniens,  which  is  yellow  with 
a  black  spot  in  the  middle  of  the  prothorax  and  one  near  the  tip  of  each 
wing-cover,  and  C.  marginatiis,  which  has  the  head  and  lower  part  of  the 
thighs  orange.  Telephorus  is  another  common  genus  without  the  maxillary 
processes,  the  species  being  black  with  the  prothorax  partly  or  wholly  reddish 
yellow.  The  larvae  of  T.  hilineatiis,  the  two-lined  soldier-beetle,  are  velvety 
dark-brown  active  creatures  which  are  very  beneficial  in  orchards,  devour- 
ing "immense  numbers  of  such  destructive  beings  as  the  larvae  of  the  plum- 
curculio." 

Professor  Comstock  has  given  the  name  checkered  beetles  to  the  family 
Cleridae;  a  name  apt  enough  for  some  of  the  species  which,  like  the  one 
shown  in  Fig.  372,  have  the  body  conspicuously  marked  with  red  and  white 
or  other  colored  "checks."  Other  species,  however,  content  themselves 
with  a  monochrome  coat.  The  family  is  a  fairly  large  one,  over  a  hundred 
species  being  known  in  this  country.  "The  adults  are  found  on  flowers 
and  on  the  trunks  of  trees  running  about  rapidly,  somewhat  resembling 
brightly  colored  ants.  Indeed  some  are  decidedly  ant-like,  the  prothorax 
being  narrower  than  the  wing-covers  and  slightly  narrower  than  the  head. 
The  legs  of  the  Clerids  are  rather  long,  the  antennae  with  a  marked  knob 
at  the  end,  and  the  body  more  or  less  cylindrical,  either  hairy  or  not. 

"The  larvae  are  usually  carnivorous  and  are  most  frequently  found 
in  the  burrows  of  wood-boring  insects,  chiefly  of  those  that  live  in  sap-wood; 
others  are  found  in  the  nests  of  bees,  and  still  others  feed  on  dead  animal 
matter."  The  slender  larvae  possess  short  legs  and  a  somewhat  prominent 
and  pointed  head.  They  are  extremely  useful  in  keeping  in  check  such 
destructive  beetles  as  bark-beetles  and  other  borers. 

The  species  of  Clerus  are  prettily  marked  and  are  often  found  running 
about  on  logs  and  trees.  C.  diibins  is  ^  inch  long,  steel-blue  with  three 
orange  bands  across  the  elytra;  C.  nigrifons  is  j  inch  long,  tawny  yellow 
with  smoky  markings  above  and  all  black  below;  C.  nigripes  is  similar, 
but  all  red  below;  C.  sanguineus  has  the  thorax  brown  and  elytra  scarlet. 
The  species  of  Trichodes  (Fig.  372)  are  hairy  and  prettily  banded;  the  larvae 
live  in  nests  of  bees,  and  T.  apiarius  is  a  pest  in  beehives  in  Europe. 
Necrohia  violacea,  \  inch  long  or  less,  dark  or  greenish  blue,  is  an  importa- 
tion from  Europe  and  is  sometimes  found  in  houses,  but  more  commonly 
on  carcasses  and  especially  the  bones  of  dead  animals.  It  has  been  found 
under  the  wrappings  of  Egyptian  mummies.  Necrohia  rnfipes,  the  red- 
legged  ham-beetle,  a  red-legged  steel-blue  species  ^  inch  long,  feeds  on  hams 
and  other  stored  animal  products.  The  beetles  lay  their  eggs  in  May  and 
June  on  exposed  hams  or  other  meats.     The  larvae  hatch  in  a  few  days  and 


Beetles 


271 


are  slender  white  active  grubs  with  a  brown  head  and  brownish  patches 
above  and  two  small  hooks  at  the  end  of  the  body.  They  feed  on  the  meat 
until  full-grown,  when  they  either  burrow  deeper  into  the  meat  or  come  out 
and  bore  into  the  wooden  receptacle  holding  it,  and  make  a  glistening  paper- 
like cocoon  within  which  they  pupate. 

The  family  Ptinidie  is  composed  of  small  obscure  brownish  beetles  that 
would  never  attract  our  attention  at  all  were  it  not  for  the  injurious  food- 
habits  of  many  of  the  species.  The  family  includes  a  hundred  and  fifty 
species,  and  among  them  a  few  notorious  pests  of  rather  unusual  tastes. 
As  the  Ptinids  mostly  live  on  dead  and  dry  vegetable  matter,  it  was  not 
improbable  when  I  began  a  collecting  expedition  in  a  d  ug-store  that  I  should 
find  a  number  of  specimens  of  this  family.  But  to  find  a  majority  of  the 
canisters  and  jars  containing  vegetable 
drugs  in  the  condition  of  roots,  stems, 
leaves,  etc.,  infested  by  beetles  of  this 
family  was  unexpected.  The  most 
abundant  species  on  this  collecting- 
ground  was  Sitrodrepa  panicea  (Fig. 

^ 7 s),  which  we  may  well  call  the  "drug-  „                ^,      ,                ,      ,      ^• 

"^'^^'            ,             ^■'               .         ,            ^'^  Fig.   373.— The  drug-store  beetle,  Sitro- 

Store    beetle.         It    was    found    to    be  drepa  panicea,  larva  pupa,  and  adults, 

attacking  blue-flag   rhizome,  comfrey-  (After  Howard  and    Marlatt;     much 

,      ,                  ,           .              ,  .  enlarged.) 
root,     dogbane-root,     gmger-rhizome, 

marshmallow-root,  aniseed,  aconite-tuber  (deadly  poison  to  us!),  musk-root, 
Indian-turnip  rhizome,  belladonna-root,  witch-hazel  leaves,  powdered  coffee- 
seed,  wormwood  stems,  flowers  and  leaves,  thorn-apple  leaves,  cantharides 
(dried  bodies  of  blister-beetles),  and  thirty  other  different  drugs!  Larvae, 
pups,  and  adults  were  side  by  side  in  most  of  the  canisters.  Ptinus  brim- 
neus,  a  larger  Ptinid,  was  in  half  a  dozen  jars,  and  the  cigarette-beetle, 
Lasiderma  serricorne,  suggestively  named,  though  it  feeds  on  tobacco  in 
almost  any  form,  was  living  contentedly  in  a  jar  of  powdered  ergot. 

"Death-watch"  is  a  name  popularly  applied  to  several  species  of  Ptinids 
because  of  their  habit  of  rapping  their  heads  so  sharply  against  wood  in 
which  they  are  burrowing  as  to  make  a  regular  tapping  or  ticking  sound. 
This  name  is  claimed  by  species  of  Anobium,  tiny,  robust,  hard-bodied,  cin- 
namon-colored beetles,  gV  inch  long,  and  also  by  Sitrodrepa  panicea,  our 
drug-store  beetle.  Comstock  records  finding  this  species  breeding  in 
large  numbers  in  an  old  book,  a  copy  of  Dante's  Divine  Comedy,  printed 
in  1536.     Librarians  wovfld  call  the  beetle  a  "bookworm." 

Besides  the  small  members  of  the  family  which  feed  on  dried  foods, 
drugs,  etc.,  there  are  a  few  larger  species  of  very  different  habits,  although 
also  destructive.  The  apple-twig  borer,  Amphiceriis  bicaiidahis,  ^  inch 
long,  dark  chestnut-brown  above  and  black  beneath,  is  the  best  known  of 


272 


Beetles 


these.  It  bores  into  live  apple-twigs  in  early  spring,  entering  close  to  a 
bud,  and  making  a  burrow  several  inches  long  for  food  and  shelter.  Twigs 
of  pears  and  cherries  are  similarly  infested.  Both  sexes  bore  these  tunnels; 
the  males  have  two  sharp  little  horns  on  the  prothorax.  The  eggs  are  laid 
in  the  dead  or  dying  shoots  of  the  greenbrier  (Smilax)  or  in  the  dead  shoots 
of  grape.  The  larvaj  feed  on  these  roots  or  shoots  and  pupate  in  them. 
The  remedy  is  to  cut  off  and  burn  infested  twigs,  and  to  keep  greenbrier 
from  growing  near  the  orchard.  The  red-shouldered  sinoxylon,  Sinoxylon 
basilare,  |  inch  long,  black  with  large  reddish  blotch  at  the  base  of  each 
wing-cover,  has  a  larva  which  bores  into  the  stems  of  grape-vines  and  into 
twigs  of  apple  and  peach.  This  larva  is  a  much-wrinkled  grub,  yellowish 
white  with  swollen  anterior  segments,  three  pairs  of  short  legs,  a  small  head, 
and  an  arched  body.  The  pupa  is  formed  inside  the  burrow  and  is  of  a 
pale-yellowish  color.  The  only  remedy  is  to  remove  and  burn  the  infested 
canes  and  twigs. 

TRIBE   LAMELLICORNIA. 

In  this  tribe  are  only  two  families,  one  small  but  containing  strangely 
shaped  and  interesting  beetles,  the  other  very  large.  In  both  the  terminal 
segments  of  the  antennas  have  conspicuous  lateral  prolongations  in  the  shape 
of  teeth  or  plates  (lamellas)  (Fig.  340,  s  and  9).  The  families  may  be  dis- 
tinguished as  follows: 

Antennae  elbowed,  the  club  (terminal  segments)  composed  of  segments  with  fixed 
transverse  teeth;    mandibles  of  the  male  often  greatly  developed. 

(Stag-beetles.)     Lucanid^e. 
Antennae  not  elbowed,   the  club  composed  of  segments    modified  to  be  large  flat 
plates  which  can  be  shut  together  like  the  leaves  of  a  book;    mandibles  of 
males  not  greatly  enlarged. 

(Lamellicorn  leaf-chafers  and  scavenger-beetles.)     Scarab.eid.^. 

The  stag-beetles,  Lucanidae,  get  their  name  from  the  extraordinary 
hyper-development  and  curious  branching  stag-horn-like  processes  of  the 
males  of  certain  of  the  larger,  more  conspicuous  species.  Only  fourteen 
or  fifteen  North  American  species  of  stag-beetles  are  known,  but  the  abun- 
dance and  striking  appearance  of  several  of  them  make  the  family  a  well- 
known  one.  The  adult  beetles  are  found  on  trees,  where  they  presumably  live 
on  the  sap  flowing  from  bruised  places,  and  on  honey-dew  secreted  by  aphids 
and  scale-insects.  In  captivity  they  will  take  moistened  sugar.  Comstock 
believes  that  some  species  feed  on  decomposing  wood.  The  large  white 
globular  eggs  are  laid  in  crevices  of  the  bark  near  the  base  of  the  trunk, 
and  the  white,  soft,  fat-bodied  larvae  (grubs)  burrow  into  the  tree  either  in 
rotten  or  sound  wood,  and  live  there  for  a  long  time.  It  is  said  that  the 
larvae  of  some  of  the  larger  species  require  six  years  to  complete  their  growth. 


Beetl 


es 


'^IZ 


The  genus  Lucanus  contains  four  North  American  species,  three  of  which 
are  familiar.  L.  elaphiis  (Fig.  374),  the  giant  stag-beetle,  of  the  southern 
states,  varies  from  i^  to  2  inches  in  length,  not  including  the  mandibles, 
which  in  the  male  are  i  inch  long  and  branched;  L.  dama,  the  common 
pinching-bug  of  the  East,  rich  mahogany-brown  in  color,  from  i  inch  to 
I J  inches  long,  "flies  by  night  with  a  loud 
buzzy  sound  and  is  often  attracted  to  lights 
in  houses,"  and  has  a  white  grub  larva 
looking  like  the  white  grub  of  the  June-bug, 
but  found  in  partially  decayed  trunks  and 
roots  of  apple-,  cherry-,  willow-,  and  oak- 
trees  instead  of  in  the  ground;  L.  placidits, 
not  quite  an  inch  long,  and  black,  is  a  third 
common  species.  The  antelope-beetle, 
Dorcus  paralleliis,  is  less  than  an  inch  long, 
black,  and  with  longitudinal  grooves  on  the 
elytra.  Platycercus  quercus,  |  inch  long, 
brownish  black,  is  widely  distributed. 
Ceruchus  piceus,  J  inch  long  and  dark  brown, 
is  occasionally  common  in  rotten  wood. 
The  horned  Passalus,  P.  corniitus,  large 
and  shining  black,  has  a  short  horn  bent 
forward  on  top  of  its  head. 

The  great  family  Scarabaeidae,  com- 
prising over  five  hundred  species  of  North 
American  beetles,  includes  some  of  our  most  familiar  kinds.  Indeed 
so  many  common,  conspicuous,  and  interesting  Scarabaeid  beetles  are  to  be 
found  by  any  collector,  or  observed  by  any  amateur  naturalist,  that  the  two 
or  three  pages  of  this  book  which  can  be  devoted  to  them  are  confessedly 
miserably  inadequate  to  help  any  one.  The  characteristic  club  of  the 
antenna?  and  heavy  robust  June-bug  type  of  body  make  most  of  the  members 
of  this  family  readily  recognizable.  In  practically  all,  too,  the  anterior 
tibiae  are  broad  and  flattened  and  fitted  for  digging.  Depending  on  their 
habits,  the  Scarabaeids  are  readily  divided  into  two  principal  groups,  the 
scavengers,  of  which  the  tumble-bugs,  dung-beedes,  etc.,  are  examples, 
and  the  leaf-chafers,  of  which  the  June-bugs,  rose-bugs,  rhinoceros-beetles, 
fig-eaters,  and  flower-beetles  are  examples.  Some  entomologists  divide 
the  Scarabaeids  into  several  distinct  families,  but  niost  do  not.  The  scavenger 
Scarabaeids  are  beneficial  to  man  by  their  eating  or  burying  of  decaying 
matter,  but  the  leaf-chafers  are  harmful,  some  of  them  being  serious  pests. 
The  Scarabasid  larvae  (Fig.  376)  are  thick,  soft-bodied,  whitish,  six-footed 
grubs,  which  usually  lie  curved  and  often  on  one  side.     They  are  found 


Fig.   374.  —  Stage-beetle,     Lucanus 
elaphus  male.     (Natural  size.) 


2/4 


Beetles 


in  manure,  rotten  wood,  and  in  the  ground.     The  familiar  white  grub,  larva 
of  the  June-bug,  is  a  typical  example. 

Of  the  scavenger  Scarabasids  the  tumble-bugs  are  wide-spread  and  well 
known.  The  species  common  in  the  East  belong  to  three  genera:  Copris, 
with  middle  and  posterior  tibiae  dilated  at  the  tip;  Canthon,  with  these  tibae 
slender  or  only  slightly  dilated ;  and  Phaneus,  with  the  anterior  tarsi  wanting, 
and  the  others  without  claws.  The  species  of  Canthon,  male  and  female 
working  together,  make  balls  of  dung,  which  are  rolled  along  for  some  dis- 
tance and  iinally  buried  in  the  ground.     The  female  lays  an  egg  in  the  ball, 


Fig.  375. 


Fig.  377. 


Fig.  376. 

Fig.  375. — Polyphylla  crinita.     (Natural  size.) 

Fig.  376. — Larva  of  a  large  Scarabeid  beetle.     (Natural  size.) 

Fig.  377. — Phaneus  cartiifex.     (One  and  one-half  times  natural  size.) 


and  the  fat  white  grub  hatching  from  it  feeds  on  the  ball  until  ready  to  pupate. 
The  adult  beetle  issues  in  about  two  weeks  from  the  time  of  laying  the  egg. 
The  common  Copris  Carolina  does  not  make  a  ball,  but  digs  holes  close  to 
or  under  manure,  and  tills  the  holes  with  this  substance,  on  which  the  larvae, 
hatched  from  eggs  placed  one  in  each  hole,  feed.  The  species  of  Phaneus 
(Fig.  377)  are  brilliantly  colored  with  metallic  green,  rose,  and  bronze,  and 
bear  curious  projecting  horns  on  the  prothorax.  The  famous  Sacred  Scara- 
beus  of  the  Egyptians,  Ateuchns  sacer,  was  "held  in  high  veneration  by 
this  ancient  people.  It  was  placed  by  them  in  the  tombs  with  their  dead; 
its  picture  was  painted  on  their  sarcophagi,  and  its  image  was  carved  in 
stones  and  precious  gems.  These  sculptured  beetles  can  be  found  in  almost 
any  collection  of  Eg}'ptian  antiquities." 

Common  dung-beetles  are  the  numerous  species  of  Aphodius,  ^  to  ^ 
inch  long,  with  oblong,  convex,  or  cylindrical  body,  and  with  the  front 
of  the  head  expanded  shield-like  over  the  mouth-parts.  "These  insects 
are  very  abundant  in  pastures  in  the  dung  of  horses  and  cattle,  and  immense 
numbers  of  them  are  often  seen  flying  through  the  air  during  warm  autumn 
afternoons."     Common  species  are  yl.  fimetarius,  ^  inch  long,  with  red  elytra; 


Beetles 


275 


A.  oblongus,  ^  inch  long,  wholly  black;  and  A.  terminalis,  \  inch  long,  black 
with  reddish  legs  and  tips  of  elytra.  The  earth-boring  dung-beetles, 
Geotrupes,  have  ii-segmented  antennse,  and  the  upper  lip  and  mandibles 
can  be  seen  from  above.  "The  females  bore  holes  into  the  earth  either 
beneath  dung  or  near  it:  this  is  to  serve  as  food  for  the  larvae,  an  egg  being  laid 
in  each  hole."  G.  splendidus  (PI.  II,  Fig.  6),  f  inch  long,  dark  metallic 
green  to  purple;  G.  excrementi,  \  inch  long,  is  bronze-black;  G.  opacus,  J  inch, 
is  deep  black.  Common  on  dried  decaying  animal  matter,  especially  skins, 
and  on  the  hooves  and  hair  of  decaying  animals  are  small  (^  to  +  inch  long) 
rough  convex  beetles,  often  with  a  crest  of  dirt  on  their  elytra,  belonging 
to  the  genus  Trox.  They  have  the  thighs  of  the  front  legs  greatly  dilated. 
The  Scaraba^id  leaf-chafers  are  many  and  various  in  color  and  marking; 
they  feed,  when  adult,  on  leaves,  pollen,  and  flower-petals.  They  have  the 
abdomen  usually  projecting  beyond  the  wing-covers.  The  thick,  fat,  white, 
horny-headed  larvas  hve  either  in  rotten  wood  or  underground,  feeding  on 
the  roots  of  grasses  and  other  plants,  often  doing  much  damage  in  this 
way.  The  June-bugs  or  May-beetles  (Fig.  378),  familiar  big  brown  or 
blackish  buzzing  creatures,  belong  to  the  genus 
Lachnosterna,  of  which  sixty  or  more  species  are 
found  in  this  country.  They  are  but  few,  however, 
on  the  Pacific  coast.  The  larvae  are  famiUar  white 
grubs  that  live  underground  and  feed  on  the  roots 
of  grasses,  strawberries,  etc.  They  often  do  much 
damage  to  lawns.  They  live  as  larvae 
for  two  or  three  years,  and  pupate  in 
an  underground  cell.  The  adult 
beetles  fly  and  feed  at  night,  often 
injuring  the  fohage  of  cherry,  plum, 
and  other  trees.  The  familiar  rose- 
chafer,  Macrodactylus  siibspinosus 
(Fig.  379),  I  inch  long,  a  slender 
Pig.  :;y8.  Fig.  37Q.      yellowish   beetle   with   pale   red    legs, 

Fig.  378. — The  June-beetle,   Lachnosterna  does  great  damage  to  roses  and  grapes, 
fusca.    (One  and  one-half  times  natural  ^^ppgaring   in   early   summer  and  eat- 

FiG.  379.— The  rose-beetle,  Macrodactylus  ing   flowers   and   foliage.     The   larvae 
subspinosus.     (Twice  natural  size.)  jj^.g  underground,  feeding  on  the  roots 

of  various  plants,  but  especially  grasses.  The  spotted  vine-chafer,  Pelidnota 
punctata  (PI.  II,  Fig.  i^),  i  inch  long,  stout,  convex,  polished  reddish  or 
yellowish  brown,  with  three  large  black  dots  on  each  elytron,  with  under 
side  of  body  metallic  greenish  black,  flies  during  July  and  August  by  day, 
feeding  on  grape-leaves.  The  larva  lives  in  rotten  wood,  especially  the 
decaying  roots  of  apple,  pear,  hickory,  and  other   trees.     It   pupates  in  a 


2/6 


Beetles 


cell  in  the  wood.  The  goldsmith-beetle,  Cotalpa  lanigera,  of  similar  size 
and  shape,  is  gUstening,  burnished  lemon  yellow  above  with  metallic 
greenish,  golden,  and  rose  reflections;  below  it  is  copper-colored  and 
thickly  covered  with  whitish  wool,  hence  the  name  lanigera,  or  wool-bearer. 
It  appears  in  May  and  June,  flies  by  night,  and  feeds  on  the  foliage  of 
various  trees.  The  larva  lives  in  the  ground,  feeding  on  plant-roots.  It  is 
said  to  require  three  years  to  complete  its  growth. 

The  largest  beetles  in  our  country  are  the  oddly  shaped  rhinoceros-beetles, 
Dynastes,  found  in  the  south  and  west.  D.  titynis  (Fig.  380),  2^  inches  long, 
is  greenish  gray  with  scattered  black  spots  on  the  elytra;  the  male  has  a 
large  horn  on  the  head  and  three  horns,  one  larger  than  the  others,  on  the 
prothorax;  the  female  has  only  a  tubercle  on  the  head;  it  is  a  southern  species. 
D.  grantii,  of  the  west,  has  the  large  prothoracic  horn  twice  as  long  as  in 
tityrus.     In  the  West  Indies  occurs  D.  hercules,  six  inches  long!    The  larvae 


Fig.   380. — The  rhinoceros-beetle,   Dynastes  tityrus.     (Natural  size.") 

(Fig.  381)  of  these  beetles  live  in  the  roots  of  decaying  trees.  Allied  to 
Dynastes  is  the  genus  Ligyrus,  of  which  L.  rugiceps,  the  black  sugar-cane 
beetle  of  the  southern  states,  is  the  best -known  species;  it  burrows  into  the 
base  of  sugar-cane  and  sometimes  corn,  and  is  often  seriously  destructive. 
The  larva  lives  in  manure.  The  flower-beetles  are  Scarabseids  of  several 
genera,  which  are  commonly  seen  flying  from  flower  to  flower  and  feeding 
on  pollen.  The  bumble  flower-beetle,  or  Indian  Cetonia,  Euphoria  inda 
(Fig.  382),  a  common  species,  is  |  inch  long,  yellowish  brown,  with  the 
elytra  irregularly  covered  with  small  blackish  spots,  and  with  the  whole 
body  clothed  with  short  fox-colored  hairs,  it  appears  early  in  spring,  and 
flies  near  the  ground  with  a  loud  humming.  It  feeds  on  flower-pollen,  the 
tassels  and  green  silk  of  young  corn,  and  later  on  ripening  fruits  of  all  kinds; 
it  often  swarms  about  wounded  trees,  lapping  up  the  escaping  sap.  The 
larvae  feed  on  decaying  substances  underground.  The  fig-eater,  or  "southern 
June-beetle,"  AUorhina  nitida,  f  inch  to  i  inch  long,  is  rather  pointed  in 


Beetles 


277 


front,  velvety  green  with  the  sides  of  thorax  and  head  brownish  yellow;  the 
under  side  is  not  velvety,  but  metallic  green.  It  flies  with  a  loud  buzzing 
sound  and  feeds  on  ripe  fruit.  The  larva;  are  found  in  richly  manured 
soil,  feeding  on  decaying  matter.  They  cannot  use  the  short  legs  for  crawling, 
but  move  along  on  their  backs  by  means  of  stiff  bristles.     "If  put  on  a  table 


Fig.  381.  Fig.  382 

Fig.  381. — Larva  and  pupa  of  the  rhinoceros-beetle,  Dynasius  tityrus.     (After  Chittenden; 

one-half  natural    size.) 
Fig.   382. — Euphoria   inda.     (One   and  one-half  times  natural  size.) 

in  normal  position,  they  immediately  turn  upon  their  backs  and  by  the 
alternate  contractions  and  expansions  of  their  body-segments  they  wriggle 
away  in  a  straight  line." 

SECTION  TETRAMERA. 

In  the  four  families  of  beetles  constituting  this-  section  the  feet  are  appar- 
ently composed  of  four  tarsal  segments,  one  of  the  more  usual  five  being 
so  reduced  in  size  and  fused  with  the  last  segment  as  to  be  practically  indis- 
tinguishable as  a  distinct  segment  (except  in  the  Spondylidae) .  The  first 
three  tarsal  segments  are  dilated  and  furnished  with  brushes  of  hairs  on 
the  sole,  the  third  segment  being  plainly  bilobed  (Fig.  341,  12).  This 
section  is  sometimes  named  Phytophaga,  because  of  the  voracious  plant- 
feeding  habits  of  all  its  members.  The  three  principal  famihes  of  the 
section  can  be  separated  by  the  following  key: 

Body  short  and  more  or  less  oval;    antennae  short. 

Front  of  head  not  prolonged  as  a  short  broad  beak;    elytra  usually  covering  the  tip 
of  the  abdomen;    both  larvce  and  adults  live  on  green  plants. 

(Leaf-beetles.)     Chrysomelid^. 
Front  of  head  prolonged  as  a  short,  quadrate  beak;    elytra  rather  short,  so  that  the 
tip  of  the  abdomen  is  always  exposed;    larvae  live   in  seeds. 

(Pea-  and  bean-w^eevils.)     Bruchid.e. 

Body  elongate;    antennae  almost  always  long,   often  longer  than  the  body;    larvae  are 

wood -borers (Long-horn  beetles.)      Cerambycid.^. 

The  leaf-beetles,  Chrysomelidoe,  are  one  of  the  largest  of  the  beetle  fami- 
lies, over  600  North  American  species  being  known.     They  are  mostly  small, 


278  Beetles 

the  familiar  Colorado  potato-beetle  being  one  of  the  largest  species  in  the 

family;  the  body  is  short,  more  or  less  oval  in  outUne,  strongly  convex  above; 

the  head  small,  much  narrower  than  the  prothorax,  and  with  the  antennae 

inserted  widely  apart.     The  adults  walk  slowly  about  on  the  plants  on  which 

they  feed,  and  when  disturbed  usually  fold  up  the  legs  and  fall,  inert,  to  the 

ground.     However,   they   sometimes  take   readily   to   wing.     The   eggs  are 

usually  laid  in  little  groups  on  the  food-plants,  and  the  larvae,  rather  broad, 

thick,  and  roughened,  crawl  about,  exposed,  on  the  leaves  which  they  eat. 

Sometimes  they  eat  only  the  soft  tissue  of  the  leaf,  skeletonizing  it;  some  mine 

inside  the  leaf,  and  a  few  burrow  into- stems.     Most,  however,  eat  ragged 

holes  in  the  leaves,  and,  if  feeding  on   cultivated  plants,  do   great  injury. 

Indeed  there  are  perhaps  more  beetle  enemies  of  our  crops,  shade-trees,  and 

ornamental  plants  in  this  family  than  in  any  other  in  the  order. 

The    Colorado    potato-beetle,    Doryphora    lo-lineata    (Fig.    383),    with 

robust,  oval,  cream-colored  body,  and  elytra  with  five  longitudinal  black 

stripes  on  each,  is  a  notorious  Chrysomelid  whose  gradual  extension   or 

migration  eastward  from  its  native  home  in  Colorado 

created  much  excitement  forty  years  ago.     Its  native 

food-plant   is    the    sand-bur,    Solanum   rostratum,    a 

congener  of  the  potato,  but  after  1850  it  began  to  find 

its  way  to  the  potato-plants  of   the   early  settlers;    by 

1859   it   had   reached   Nebraska,  1861  Iowa,  in   1864 

and    1865    it    crossed   the    Mississippi    and  gradually 

Fig.  383.  —  The    Colo- gxtehded    eastward  until    1874,  when  it   reached    the 
rado      potato  -  beetle,    .    ,        .     ^ 
Doryphora   lo-lineata.  Atlantic  Ocean.     Fmally  It  obtained  a  partial  foothold 

(Twice  natural  size.)  jn  Europe,  creating  great  consternation  there,  but  it  has 
never  got  to  be  a  serious  pest  across  the  ocean.  The  orange-red  eggs  are 
laid  on  the  leaves,  and  the  larvae  are  curious  humpbacked  soft-bodied  crea- 
tures with  black  head  and  Venetian-red  body.  They  crawl  down  and  bur- 
row into  the  ground  to  pupate.  There  are  three  generations  a  year  in  the 
latitude  of  St.  Louis,  the  beetles  of  the  last  brood  crawling  underground 
to  hibernate. 

The  common  asparagus-beetle,  Crioceris  asparagi,  red,  yellow,  and  black, 
gnaws  holes  in  young  asparagus-heads,  and  the  brown  slug-Hke  larvae  which 
hatch  from  oval  blackish  eggs  laid  on  the  heads  also  eat  them.  The  three- 
lined  Lema,  Lema  trilineata,  of  similar  shape,  but  yellow  with  three  longi- 
tudinal black  stripes  on  each  elytron,  is  common  on  "ground-cherries." 
Their  larvae  have  the  curious  habit  of  covering  their  backs  with  their  own 
excrement.  Elm-trees  in  the  East  are  often  badly  infested  with  the  imported 
elm-leaf  beetle,  Galerucella  luteola  (Fig.  384),  a  common  European  pest. 
It  first  got  to  this  country  in  1834  and  is  now  "in  all  probability  responsible 
for  more  ruined  elm-trees  in  the  Hudson  River  valley  than  all  other  destruc- 


Beetles 


279 


tive  agencies  combined."  The  beetle,  ^  inch  long,  is  reddish  yellow  with 
black  spots  on  head  and  prothorax,  and  a  thick  black  stripe  on  each  elytron. 
From  orange-yellow  eggs  laid  on  the  under  side  of  the  leaves  hatch  larvae 
which  when  full  grown  are  ^  inch  long,  flattened,  marked  with  blackish 
and  yellow.  They  skeletonize  the  leaves.  When  ready  to  pupate  they 
crawl  down  into  the  ground.  The  beetles  themselves  after  issuance  fly  back 
to  the  tree-tops  and  eat  holes  in  the  leaves.  There  are  two  broods  a  year, 
and  the  adult  beetles  of  the  last  brood  hibernate  in  concealed  places. 


Fig.  384. — The  elm-leaf  beetle,  Galerucella  liiteola;  eggs,  larvae,  pupa,  and  adults.     (After 
Felt;    eggs  greatly  magnified;    larvae,  pupa,  and  adults  about  twice  natural  size.) 

Four  species  of  the  genus  Diabrotica  are  common  over  the  country  and 
very  injurious:  D.  vittata,  the  striped  cucumber-beetle,  is  greenish  yellow 
with  two  black  stripes  on  each  elytron,  and  feeds  on  cucumber-,  pumpkin-, 
squash-,  and  melon-vines,  the  larva  also  burrowing  into  the  stems  and  roots 
of  the  same  plants;  D.  12-piinctata  (Fig.  385)  is  greenish  yellow  with  six 
black  spots  on  each  elytron,  and  feeds  on  a  great  variety  of  plants,  the  larva 
often  being  injurious  to  corn  in  the  South;  D.  longicornis,  the  corn-root- 
worm  beetle,  is  grass-green  with  spots  or  stripes,  and  its  underground  larva 
is  very  destructive  to  corn  by  burrowing  into  its  roots;  D.  soror  (Fig.  386)^ 
of  the  Pacific  coast,  the  flower-beetle  or  "diabrotica,"  yellowish  green  with 


28o 


Beetles 


six  black  spots  on  the  wing-covers  (like  l2-punctata),  does  great  damage  as 
an  adult  by  eating  into  the  flower-buds  of  roses,  chrysanthemums,  and  a 
host  of  others,  the  larva  feeding  on  the  roots  of  alfalfa,  chrysanthemums, 
and  many  other  plants. 


Fig.  385.  Fig.  386. 

Fig.  385. — The  cucumber-beetle,  Diabrotica  12-punctata. 
Fig.  386.— The  California  flower-beetle,  Diabrotica  soror. 
Fig.  387. — Chrysomela  digsbyana.     (Twice  natural  size.) 


Fig.  387. 

(Three  times  natural  size.) 
(Three  times  natural  size.) 


Chrysochus  auratus  (PI.  II,  Fig.  4),  f  inch  long,  golden  green  in  color, 
found  in  the  East,  and  C  cobaltinus  (PI.  II,  Fig.  7),  of  same  size  and  shape, 
but  brilliant  blue,  found  in  the  West,  are  the  two  most  beautiful  Chrysomelids. 

Chrysomela  (Fig.  387)  is  a 
genus  whose  species  are  often 
curiously  marked  with  short, 
curved  lines  and  irregular 
spots.  The  active  little  flea- 
beetles,  with  swollen  hind 
femora,  and  able  to  leap  vigor- 


Fig.  388.  Fig.  389. 

Fig.   388.— Larvae  of  the  grape-vine  flea-beetle,  Haltica  chalybea.     (After  Slingerland; 

much  enlarged.) 
Fig.  389.— a  tortoise-beetle,  Coptocyda  aurichalcea.     (Two  and  one-half  times  natural 

size.) 

ously,  are  common  pests  of  grapes,  cucumbers,  melons,  cabbages,  turnips,  etc., 
numerous  species  being  known.  They  are  small,  usually  about  -^\  to  \  inch 
long,  and  commonly  blackish  or  steel-blue  in  color.  Haltica  chalybea,  the  steel- 
blue  flea-beetle  (Fig.  388),  is  common  on  grape-vines,  where  it  feeds  on  the 


Beetles 


281 


fruit  and  leaves;  Crepidodera  aicimieris,  the  cucumber  flea-beetle,  ^V  i^^ch 
long,  and  black,  attacks  melons,  cucumbers,  and  other  vegetables.  The 
tortoise-beetles  (Fig.  389)  are  curiously  shaped,  flat  beloM^,  convex  above,  and 
with  the  prothorax  and  elytra  thinly  margined  so  as  to  give  them  a  tortoise-like 
appearance  from  above;  they  are  usually  iridescent  greenish  and  golden  in  color, 
and  are  often  called  goldbugs.  The  colors  appear  and  disappear  strangely 
while  the  insects  are  alive,  but  are  always  lacking  in  the  dead  specimen. 
Coptocycla  clavata  has  two  projections  of  the  central  dark  color  of  each 
elytron  looking  like  the  four  short  broad  legs  of  a  tortoise;  Cassida  bicolor 
is  like  "a  drop  of  burnished  gold";  Chelymorpha  argiis,  |  inch  long,  brick- 
red  with  many  black  spots  on  prothorax  and  elytra,  is  found  on  milkweeds; 
Physonota  imipunctala,  ^  inch  long,  the  largest  of  our  tortoise-beetles,  yellow 
with  whitish  margins,  is  common  in  midsummer  on  wild  sunflowers. 

The  small  familv  Bruchidae  contains  two  common  and  important  beetles, 
viz.,  the  pea-weevil,  Bntchus  pisl  (Fig.  390),  and  the  bean-weevil,  B. 
obtectiis  (Fig.  391).  The  adult  pea-weevil  is  \  inch  long,  general  color  rusty 
or  grayish  black  with  a  small  white  spot  on  the  thorax.  The  eggs  are  small, 
fusiform,  and  yellow.  The  grubs  on  hatching  bore  through  the  pod  into 
the  peas.  The  hole  made  in  the  growing  pea  soon  closes  up,  leaving 
the  voracious  larva  within.  Here  it  often  comes  to  an  untimely  end, 
— which  is  uncomfortable  to  think  about.  If,  however,  the  peas  are 
allowed   to   ripen   and   are   put   away   for  seed,   it   eats   on   until   there    is 


Fig.  3QO.  Fig.  391. 

Fig.  390. — The  pea-weevil,  Bnichus  pisi,  and  an  infested  pea.     (Natural  size  of  beetle 

indicated  by  line.) 
Fig.    391. — The   bean-weevil,    Bnichus  ohtectus,   and   an   infested   bean.     (Natural  size 

of  beetle  indicated  by  line.) 


only  a  shell  left  of  the  pea.  Weeviled  peas  are  unfit  for  food,  and,  as 
proved  by  the  experiments  of  Professor  Popenoe,  should  not  be  used  for 
seed.  During  the  fall  and  winter  the  larvae  pupate  and  finally  mature  as 
weevils  (the  adult  beetles).  Some  of  the  beetles  emerge  from  the  peas, 
while  others  remain  in  them  until  they  are  planted. 


282 


Beetles 


"Weevily"  peas  should  be  put  into  a  tight  box  or  bin,  together  with  a 
small  dish  of  bisulphide  of  carbon,  the  fumes  of  which  will  kill  the  insects. 
Or  they  may  be  immersed  for  a  minute  or  two  in  water  heated  to  140'='  F.; 
this  will  kill  all  the  beetles  and  larvas. 

The  bean-weevil  is  a  little  larger  than  the  pea-weevil  and  lacks  the 
white  spot  on  the  thorax.  Its  Hfe-history  is  about  the  same  as  that  of  the 
pea-weevil,  the  eggs  being  laid  of  course  on  the  young  bean-pods.  Several 
eggs  are  frequently  laid  in  a  single  bean.  The  bean- weevil  continues  to 
breed  also  in  dry  stored  beans,  and  increases  its  damage  materially  if  the 
stored  beans  lie  long  untouched.  It  is  therefore  necessary  to  treat  weeviled 
beans  with  bisulphide  of  carbon  or  hot  water  before  storing  them  away. 


Fig.  393. 

Fig.  392. — Prionus  californiciis.     (Natural  size.) 

Fig.  393. — Larva  of  Ergates  spiculatiis.     (Natural  size.) 


Fig.  392. 
392. — Prionus  californiciis. 


The  other  principal  tetramerous  family  besides  the  Chrysomelids  is  the 
Cerambycidae,  or  family  of  long-horn  wood-boring  beetles:  "long  horn" 
because  of  their  long  slender  antennae,  and  "wood-boring"  because  their 
larvffi  live  in  burrows  in  the  trunks  of  trees.  The  beetles  themselves  are 
usually  large  and  strikingly  colored  and  patterned,  and  whenever  seen 
attract  attention.  Nearly  600  species  are  known  in  North  America,  and 
they  are  common  all  over  the  country.  As  might  be  concluded  from  the 
habits  of  the  larvae,  the  family  includes  numerous  serious  pests,  such  species 
as  the  round-headed  apple-tree  borer,  the  oak-pruners,  various  hickory- 
borers,  the  twig-girdlers,  the  giant  Prionids  et  al.,  all  causing  much  damage 
to  orchards  and  forests. 


Beetl 


es 


283 

The  eggs  are  usually  laid  on  the  bark,  and  the  whitish,  usually  footless 
soft-bodied  but  hard-headed  and  strong-jawed  larvae  burrow  about  in  the 
tree-trunk  for  a  year  or  two  or  even  three  (varying  with  the  different  species) 
feeding  on  the  chewed  wood.  They  pupate  in  the  burrow,  in  a  cell  par- 
titioned off  with  chips,  or  sometimes  specially  made  just  under  the  bark 
The  beetle  has  only  to  gnaw  its  way  through  the  bark  or  the  loosely  plugged 
burrow  to  escape  from  the  tree.  These  wood-borers  usually  select  a 
weakened  or  dying  tree  for  attack. 

The  largest  Cerambycids  belong  to  the  subfamily  Prionida?  (Fig    SQ2) 
whose   members   have   the   sides   of   the   prothorax   sharply   margined   and 
usually  toothed.     Prionus  laticoUis,  the  broad-necked  Prionus,  varies  from 


Fig.  394.— The  sugar-maple  borer,  Plagionotus  speciosiis,  larva;  and  adult  beetle.     (After 

Felt;    natural  size.) 

I  inch  to  2  inches  in  length,  and  is  pitchy  black  or  brown,  the  prothorax 
with  three  sharp  teeth  on  each  lateral  margin,  and  the  antennae  12-segmented; 
the  larvffi,  which  live  three  years,  are  great  footless  white  grubs,  2^  to  3 
inches  long,  which  burrow  in  the  roots  of  oak,  poplar,  cherry,  apple 
grape-vine,  and  blackberries.  The  tile-horned  Prionus,  P.  imbricornis 
a  similar  beetle,  has  nineteen  antennal  segments  in  the  male  and  usually 
Sixteen  in  the  female;    OrtJiosoma    brunnea,   is   long  (li  to  2*  inches)  and 


284 


Beetles 


narrow,  with  the  margins  of  the  body  nearly  parallel.  In  the  south  occurs 
the  genus  Mallodon,  and  on  the  Pacific  coast  the  genus  Ergates  (with  a 
single  species,  spiailatHs),  both  2 J  inches  long,  and  with  the  lateral  margins 
of  the  prothorax  with  many  fine  sharp  teeth.  The  larvae  (Fig.  393)  of 
Ergates  live  in  the  giant  sugar  and  yellow  pines  of  the  Sierra  Nevada  forests. 
The  cloaked  knotty-horn,  Desmocerus  palliatus  (PI.  II,  Fig.  i),  is  a 
beautiful  species,  dark  greenish  blue  with  the  bases  of  the  elytra  orange- 
yellow;  the  larvae  bore  in  elder-pith.     Cyllene  robinicr,  the  locust-borer  (PI.  II, 


Fig.  395. 


-Maple-tree  borer,  Elaphidion  villosum,  larva,  pupa,  and  adult  beetle, 
(After  Felt;    natural  size.) 


Fig.  15),  is  black,  with  striking  yellow  bands  often  found  on  goldenrod; 
its  larvae  live  in  locust-trees.  A  similar  species,  Cyllene  pictus,  attacks  the 
hickory.  The  red  milkweed-beetle,  Tetraopes  tetraopthalmus  (PI.  II, 
Fig.  10),  brick-red  with  black  spots,  is  a  common  species  on  milkweeds; 
the  larvae  bore  into  the  lower  stems  and  roots.  Two  beautiful  Cerambycids 
of  California  are  shown  in  Figs.  2  and  1 6  of  PI.  II. 

The  sugar-maple  borer,  Plagionotiis  speciosus  (Fig.  394),  is  a  serious 
pest  of  sugar-maples  in  New  York  and  elsewhere  in  the  East.  The  beetle, 
I  inch  long,  is  black,  brilliantly  marked  with  yellow;    the  eggs  are  laid  in 


Beetles  28  c 

July  or  August  in  the  bark,  the  young  borer  (a  footless,  flattened,  whitish 
grub)  burrowing  first  into  the  sap-wood,  where  it  passes  the  winter.  Dur- 
ing the  next  year  it  bores  vigorously  around  under  the  bark,  and  when  about 
sixteen  months  old  makes  a  final  deep  burrow  into  the  heart-wood,  in  the 
end  of  which  it  pupates.  Fig.  394  shows  all  the  stages  of  this  insect.  The 
maple-tree  pruner,  Elaphidion  villosum  (Fig.  395),  f  inch  long,  slender 
grayish  brown,  lays  its  eggs  on  small  twigs  in  maple-trees  in  July;  the  larvae 
bore  into  the  center  of  the  twig,  eat  out  a  large  portion  of  the  woody  fiber, 
plug  the  end  of  the  burrow  with  castings,  and  wait  for  a  strong  wind  to  break 
off  the  nearly  severed  branch.  In  the  fallen  twigs  thus  broken  off  the 
larvae  pupates,  and  the  beetles  issue,  the  life-history  taking  just  about  a  year 
for  completion.  This  pest  also  "prunes"  oaks,  and  apple,  pear,  plum,  and 
other  fruit  trees.  The  sawyers,  various  species  of  the  genus  Monohammus, 
are  beautiful  brown  and  grayish  beetles  with  extremely  long  delicate  antennc-e; 
the  larvae  bore  in  sound  pines  and  firs  and  do  great  injury  to  evergreen 
forests. 

One  of  the  worst  and  most  famihar  orchard  pests  is  the  round-headed 
apple-tree  borer,  Saperda  Candida  (Fig.  396).  The  beetle  is  f  inch  long, 
narrow,  and  subcylindrical,  pale  brown  with 
two  broad  creamy-white  longitudinal  stripes. 
The  eggs  are  laid  on  the  bark  at  the  base  of 
the  tree  in  June  and  July.  The  larva  works 
at  first  in  the  sap-wood,  making  a  flat  shallow 
cavity  filled  with  sawdust  and  castings;  later 
it  burrows  deeper  and  works  upward.  When 
nearly  three  years  old  it  bores  a  tunnel  from 
the  heart-wood  out  nearly  to  the  bark,  partly  F,o^3Q6.-The  round -heLd 

fallmg    the    outer    part  with    sawdust    and   then        apple-tree  borer,  Saperda  cau- 

retires  to    the  inner   end   and   pupates.     Two      f?/'  ^^^^"^  .''"'^  '"^''^^  ^^'^t'^- 

.1  1         r.  .         ,  .    ,  (After  Saunders;  natural  size.) 

or  three  weeks  after  pupation  the  adult  beetle 

issues  from  the  pupal  skin,  works  outward  along  the  tunnel  and  cuts  a 
smooth  circular  hole  in  the  bark  through  which  it  escapes.  When  several 
larvas  are  working  in  a  tree  they  may  completely  girdle  it,  so  that  it  dies. 
The  most  effective  remedy  is  to  apply  a  repellent  wash  of  lime  or  soft  soap 
from  the  base  of  the  trunk  up  to  the  first  branches  several  times  during  the 
egg-laying  time,  i.e.,  June  and  July. 

A  small  family,  Spondylida?,  called  the  aberrant  long-horned  beetles,  is 
represented  in  North  America  by  four  species,  of  which  the  most  common 
is  Parandra  brunnea  (PI.  II,  Fig.  14),  a  beautiful  polished  mahoganv- 
brown  beetle  found  under  the  bark  of  pine-trees. 


286  Beetles 


SECTION  TRIMERA. 

Only  one  family  is  included  in  this  section  of  beetles  with  but  three  tarsal 
segments  in  each  foot,  namely,  the  familiar,  little  ladybirds  or  plant-louse 
beetles,  the  Coccinellidte.  Their  uniformly  small  size,  the  semispherical  shape, 
and  the  "polka-dot"  pattern  distinguish  them  readily  from  all  other  beetles 
except  perhaps  the  Chrysomelids,  a  few  of  which  are  often  mistakenly 
called  ladybirds.  This  is  a  particularly  unfortunate  confusion  because  of 
the  radically  different  food-habits  and  consequent  economic  relation  to 
man  of  the  two  families.  The  Chrysomehdae,  or  leaf-eaters,  both  as  larvse 
and  adults,  attack  our  crops  and  trees  and  flowers;  the  CoccinelHdae,  or 
ladybirds,  both  as  larvae  and  adults,  feed  on  plant-lice  and  scale-insects, 
great  enemies  of  our  orchards  and  gardens,  and  thus  are  among  our  best 
insect  friends.  A  friend  of  mine  found  that  his  roses  were  suffering  from 
insect  attack;  he  saw  httle,  convex,  black-spotted  reddish  beetles  clamber- 
ing busily  up  and  down  the  stems,  and  he  set  to  work  to  pick  these  off  one 
by  one  and  drop  into  a  tin  cup  with  petroleum  in  the  bottom.     When  he  had 


#    i  ^   $ 


Fig.  397. — Some  Californian  ladybird -beetles;  beginning  at  left  of  upper  row  the  species 
are  Megilla  vitigera,  CoccineUa  caJijornica,  C.  ocidata,  Hippodamia  convergens; 
beginning  at  left  of  lower  row,  CoccineUa  trifasciata,  C.  sanguinea,  C.  ahdoniinalis, 
Megilla  maculata.     (Twice  natural  size.) 

a  full  pint  he  showed  them  proudly.  But  the  more  little  round  beetles  he 
picked  off  the  more  rapidly  wilted  his  roses.  And  for  the  wholly  sufficient 
reason  that  he  was  collecting  and  killing  the  ladybirds  that  were  making 
a  fight — a  losing  one  in  the  face  of  my  friend's  active  part  in  it — against 
the  hosts  of  tiny  inconspicuous  green  rose-aphids  that  were  sucking  the  sap 
out  of  the  rose-stems  and  buds.  So  be  it  remembered  that  not  all  bugs 
are  bad  bugs,  but  that  some,  like  the  ladybirds,  are  most  effective  helpers 
in  waging  war  against  the  real  pests! 

There  are  about  150  species  of  ladybirds  known  in  the  United  States^ 
and  almost  all  are  reddish  brown  with  black  dots  or  black  with  reddish 


Beetles  287 

spots.  Their  colors  and  markings  make  them  conspicuous,  and  vet  the 
natural  enemies  of  insects,  the  birds,  obviously  let  them  alone;  it  is  presumed, 
therefore,  that  these  beetles  are  ill-tasting  to  birds,  and  that  their  bright  colors 
are  of  the  nature  of  readily  perceived  warning  signs  (see  discussion  of 
this  subject  in   Chapter  XVII). 

The  eggs  are  laid  on  the  bark,  stems,  or  leaves  of  the  tree  or  plant  on 
which  aphids  or  scale-insects  are  present.  Sometimes  they  are  deposited 
in  little  patches  right  in  the  middle  of  a  colony  of  plant-lice.  The  larva? 
(Fig.  398)  are  elongate,  widest  across  the  prothorax  and  tapering  back  to 
the  tip,  with  the  skin  usually  roughened  or  punctate,  bearing  hairs  and  short 
spines,  and  marked  with  blackish,  reddish,  and  yellowish.  The  larvae  feed 
steadily  on  the  soft  defenceless  aphids  or  young  scale-insects,  or  on  the  eggs 
and  young  of  other  larger  insects.  When  full-grown  they  pupate,  attached 
to  the  leaves  or  stems  without  entirely  casting  off  the  last  larval  exuvia  (Fig. 
398).  This  cuticle  often  surrounds  the  pupa  "like  a  tight-fitting  overcoat 
with  the  front  not  closed  by  buttons."  In  other  cases  the  larval  skin  is 
forced  backwards  and  remains  as  a  little  crumpled  pad  about  the  posterior 
end. 

The    two-spotted    ladybug,   Adalia    bi punctata,    reddish  yellow    with   a 

single  black  spot  on  each  elytron,  is  common  in  the  East,  where  it  often 

enters  houses  to  hibernate.     The  nine-spotted 

ladybird,  Coccinella  novemnotata,  has  yellowish 

elytra  with  four  black  spots  on  each  in  addition 

to  a  common    spot    just  behind    the  thorax. 

The     "twice-stabbed"     ladybird,     Chilocorus 

bivulnerits,  is  shining  black  with  a  large  red 

spot  on  each  elytron.     Anatis  ij-punctata,  the 

fifteen-spotted  ladybird,  is  a  large  species  with 

dark  brownish-red   elytra  bearing   seven  black 

spots  each,  and   a   median   common  spot   just 

behind  the  thorax.  i?,^   •     o       ^    1  j  i,-  j  u    .1 

Fig.     398.  —  A    ladvbird-beetle, 

In    California    the     ladybirds    are    of    great        Coccinella    caliloriiica ;    larva, 

importance   to   the   fruit-growers,  their   steadv       P'^''''^'  ^"'^.^'^1'^  °''  Lawson's 
,     ,        ,       ,  .  r  1     •  ,     .  '         cvprees.     (Twice  natural  size.) 

wholesale  destruction  of  scale-msects  bemg  an 

important  factor  in  successful  fruit-raising.  Fig.  397  illustrates  eight  species 
found  on  the  Pacific  coast.  A  number  of  ladybird  species  have  been  imported 
from  Australia  and  other  countries  from  which  numerous  destructive  scale- 
insects  had  been  earlier  unwittingly  brought  on  nursery  stock.  Most  conspic- 
uously successful  of  these  attempts  to  introduce  and  disseminate  original  home 
enemies  of  imported  pests  has  been  the  estabhshment  of  the  small  red-and- 
black  ladybird,  Vedalia  cardinalis,  which  feeds  exclusively  on  the  fluted  or  cot- 
tony cushion-scale  (Icerya  purchasi)  (Fig.  254).     This  Australian  scale  first 


288  Beetles 

appeared  in  California  near  Menlo  Park  in  .1868  on  orange-trees,  and  in  a 
few  years  had  become  so  abundant  and  widely  spread  over  the  state  that 
it  seriously  threatened  the  extinction  of  the  great  orange  industry.  In  1888 
a  few  live  Vedalias  (altogether  about  500  specimens  in  five  separate  lots) 
were  brought  from  Australia,  put  on  trees  infested  by  the  fluted  scale,  and 
by  helpful  scattering  of  the  progeny  of  these  original  emigrants  this  lady- 
bird species  was  soon  distributed  to  all  scale-infested  localities.  In  a  few 
years  it  had  the  pest  completely  under  control,  and  has  ever  since  remained 
its  master.     And   California  continues   to  grow  Washington  oranges. 


SECTION  HETEROMERA. 

This  section  includes  those  beetles  which  have  the  front  and  middle 
feet  with  five  tarsal  segments,  the  hind  feet  with  four.  It  is  a  heterogeneous 
assemblage,  including,  besides  two  large  families  of  u'idely  differing  aspect 
and  habits,  a  number  of  small  ones  of  obscure,  little  known,  and  mostly 
uncommon  species  of  small  size,  which  present  a  wide  variety  of  structure 
and  life-history.  The  two  principal  families  can  be  distinguished  by  the 
following   diagnosis: 

Head  without  distinct  neck,  narrower  than  thorax  and  more  or  less  inserted  in  it; 
body-wall  hard;    color  usually  black. 

(Darkling  ground-beetles.)     Tenebrionid^. 

Head  as  wide  as  prothorax,  and  attached  to  it  by  a  visible  neck;    body  soft  and 

elytra  flexible;    colors  often  diversified,    frequently  metallic  blue  or  green 

(Blister-  and  oil-beetles.)     Meloid.c 

The  common  ground-beetles  of  the  North  and  East  are  the  swift  preda- 
ceous  Carabidae;  any  stone  or  log  turned  over 
will  reveal  them.  In  the  dry  warm  western  plains 
and  southwestern  semi-desert  states,  however,  the 
slower  vegetable-feeding  Tenebrionidae  are  the  com- 
mon ground-beetles.  The  most  familiar  of  them  on 
the  Pacific  coast  are  large,  awkwardly  moving,  shin- 
ing black  pinacate  bugs,  Eleodes  (Fig.  399)  which, 
when  disturbed  by  the  turning  over  of  their  covering 
stone,  stand  on  their  fore  legs  and  head  and  emit  an 
ill  -  smelling   fluid    from   the   tip    of    the    abdomen. 

Yi(y    ,gQ_ Pinacate  bug,     They  have  no  wings,  and  the  thick  horny  elytra  are 

Eleodes  sp.  (Natural  grown  fast  to  the  back.  All  the  rest  of  the  body 
^^^^■•^  is  similarly  armor-plated,  and  the  collector  has  to  use 

an  awl  to  make  a  hole  through  the  body-wall  for  pinning  up  his  specimens. 


Beetles  289 

The  darkling-beetles  constitute  a  large  family,  more  than  four  hundred  species 
being  known  in  this  country,  although  comparatively  few  of  them  are  at 
all  familiar.  They  are  mostly  dull  or  shining  black,  and  feed  on  dry  vege- 
table matter,  often  in  a  state  of  decay.  Some  live  in  grain,  flour,  meal,  or 
sawdust;  others  in  Hving  or  dead  fungi,  and  a  few  are  probably  predaceous. 
A  common  species  in  mills,  stables,  grocery-stores,  and  pantries  is  the  meal- 
worm beetle,  Tenehrio  nwlitor,  ^  to  f  inch  long,  flattened,  brownish,  with 
squarish  prothorax  and  longitudinally  ridged  elytra.  The  stout,  cylindrical, 
hard-skinned,  waxy,  yellowish-brown  larvae,  or  meal-worms,  infest  flour 
and  meal.  They  are  often  bred  by  bird-fanciers  as  winter  food  for  insect- 
eating  song-birds.  For  this  purpose  they  are  raised  in  large  numbers  in 
warm  boxes  partly  filled  with  bran,  in  which  they  undergo  all  their  metamor- 
phosis. T.  obscurus  is  a  darker,  almost  black,  species  found  also  in  mills 
and  granaries.  Both  of  these  species  have  been  spread  all  over  the  world 
by  commerce.  A  smafler  brown  species,  Echoceriis  maxillosiis,  ^  inch  long, 
is  common  in  the  southern  states  in  old  and  neglected  flour. 

Uloma  impressa,  J  inch  long,  deep  mahogany-brown,  is  common  in  the 
east,  occurring  in  decaying  logs  and  stumps.  Smaller  species  of  the  same 
genus,  lighter  in  color,  are  also  to  be  found  in 
similar  places.  An  odd-looking  species  called 
by  Comstock  the  forked  fungus-beetle,  Boleto- 

therus  bijurcus,  is  not  uncommon  in  the  north    Fig.  400. Larva    of   a   Tene- 

and  east  in  and  about  the  large  shelf-fungi  brionid,  Boletotherus  bifurcus. 
/r>  1  \   iU    i    "  iU         -J  r    i  (Twice  natural  size.) 

(rolyporus)  that   grow  on   the   sides   of   trees. 

The  surface  of  the  body  and  elytra  is  very  rough,  and  two  conspicuous 
knobbed  horns  project  forward  from  the  prothorax.  The  larva;  (Fig.  400) 
live  in  the  fungi. 

The  other  of  the  two  larger  heteromerous  families,  the  Meloidae,  numbering 
about  200  North  American  species,  includes  beetles  of  unusual  structural 
character  and  appearance,  of  peculiar  physiological  properties,  and  of  a 
highly  specialized  and  unique  kind  of  metamorphosis.  The  Meloids  are 
known  as  oil-beetles  from  the  curious  oily  fluid  emitted  by  many  species 
when  disturbed,  and  as  blister-beetles  from  the  inflammatory  and  blistering 
effect  of  the  application  of  the  pulverized  dry  body  svibstance  to  the  human 
skin.  This  powdered  blister-beetle  is  known  to  pharmacists  as  cantharides, 
and  is  a  recognized  therapeutic  substance.  The  beetles  are  rather  long 
and  slender-legged  and  have  a  soft  fleshy  body  with  flexible  wing-covers 
which  are  sometimes  rudimentary,  being  then  short  and  diverging  (Fig. 
401).  The  head  is  broad  and  set  on  a  conspicuous  neck,  and  hangs  with 
mouth  downward.  They  are  to  be  found  crawling  slowly  about  over  field- 
flowers,  as  goldenrod,  buttercups,  etc.,  often  in  companies  of  a  score  or  more 
individuals.     Many   of   the   species   are   brightly   colored,   metallic   bronze, 


290 


Beetles 


green,  blue,  and  steel-black  being  common  colors  (PL  II,  Fig.  12).     Some, 
however,  are  grayish,  dead  black,  or  yellowish  and  brown.    All  are  leaf-feeders- 
In  the  development  of  the  blister-beetles  an  extreme  condition  known 
as  hypermetamorphosis  occurs,  which  is  undoubtedly  the  result  of  a  purpose- 
ful adaptation  brought  about   by  long  selection,  but 
which   seems    an    almost    impossible  achievement  of 
such  "blind"  natural  forces.     The  eggs  are  deposited 
in  the  ground;  from  them  hatch  minute  active  strong- 
jawed  larvae  (Fig.  402)  with  three  pairs  of  long  legs, 
each  terminating  in   three   claw-like   spines.     These 
larvse    are    called    triungulins.       They    run    about 
seeking  food,  which,  varying  with  different   species, 
consists  of   the   eggs    of   locusts,   or   the    eggs    and 
honey  of  solitary  bees.     The  triunguhn  of  Epicauta 
Fig.    401.  — The   striped   vittata,  one  of  our  common  Meloid  species,  studied 
potato-beetle,   Epicauta   ]^y  Riley,  explores  cracks  and  burrows  in  the  ground 
^wLTnatimrsize^r''''   until  an  egg-pod  of  a  locust  (usually  of  one  of  the 
destructive  Melanoplus  species)  is  found.     Into  this 
the  triungulin  burrows  and  begins  to  devour  the  eggs.     After  a  few  days 
given  to  eating  a  couple  of  eggs  it  moults  and  appears  in  a  very  different 


Fig.  402. — Hypermetamorphosis  of  Epicauta  vittata.  A,  young  larva  or  triungulin; 
B,  caraboid  larva;  C,  coarctate  larva;  D,  scarabasoid  larva;  E,  pupa;  F,  adult. 
(After  Riley;    natural  size  indicated  by  line.) 

larval  guise  with  soft  skin,  short  legs,  small   eyes,  and  different  body  form 
and  proportions.     One  week  later  a  second  moult  occurs,  but  without  re- 


Beetles  291 

vealing  much  of  a  change  in  the  larva,  although  it  is  now  more  curved,  less 
active,  and  somewhat  like  a  small  June-beetle  grub;  after  a  third  moult  it  is 
still  more  helpless  and  grub-like.  It  now  grows  rapidly.  When  full-grown 
it  leaves  the  ruined  egg-pod,  makes  a  little  cell  in  the  ground  near  by  in 
which  it  lies  motionless  except  for  a  gradual  contracting  and  slow  fourth 
moulting,  after  which  it  appears  as  a  completely  helpless  semi-pupa,  or 
coarctate  larva.  In  this  state  it  passes  the  winter.  In  spring  the  fifth 
moult  takes  place,  leaving  the  larva  much  as  before,  only  smaller  and 
whiter.  It  becomes  now  rather  active  and  burrows  about,  but  takes  no 
food,  and  after  a  few  days  again  moults  for  the  sixth  time,  to  appear  at  last 
as  a  true  pupa.     Five  or  six  days  later  the  adult  beetle  emerges. 

Those  blister-beetles  which  live  parasitically  on  bees'  eggs  instead  of  on 
those  of  the  locust  probably  follow  about  the  course  described  by  Fabre 
for  Sitaris  humeralis,  a  European  species,  an  account  of  which  I  quote 
from  Sharp  (Cambridge  Natural  History,  vol.  vi):  "The  eggs  of  the  Sitaris 
are  deposited  in  the  earth  in  close  proximity  to  the  entrances  to  the  bees' 
nests,  about  August.  They  are  very  numerous,  a  single  female  producing, 
it  is  believed,  upward  of  two  thousand  eggs.  In  about  a  month — towards 
the  end  of  September — they  hatch,  producing  a  tiny  triungulin  of  black 
color;  the  larvas  do  not,  however,  move  away,  but,  without  taking  any  food, 
hibernate  in  a  heap,  remaining  in  this  state  till  the  following  April  or  May, 
when  they  become  active.  Although  they  are  close  to  the  abodes  of  the 
bees,  they  do  not  enter  them,  but  seek  to  attach  themselves  to  any  hairy  object 
that  may  come  near  them,  and  thus  a  certain  number  of  them  get  on  to  the 
bodies  of  the  Anthophora  [the  bees]  and  are  carried  to  its  nest.  They 
attach  themselves  with  equal  readiness  to  any  other  hairy  insect,  and  it  is 
probable  that  very  large  numbers  perish  in  consequence  of  attaching  them- 
selves to  the  wrong  insects.  The  bee  in  question  is  a  species  that  nests  in 
the  ground  and  forms  cells,  in  each  of  which  it  places  honey  and  lays  an 
egg,  finally  closing  the  receptacle.  It  is  worthy  of  remark  that  in  the  case 
of  the  Anthophora  observed  by  M.  Fabre  the  male  appears  about  a  month 
before  the  female,  and  it  is  probable  that  the  vast  majority  of  the  predatory 
larva2  attach  themselves  to  the  male,  but  afterwards  seize  a  favorable  oppor- 
tunity, transfer  themselves  to  the  female,  and  so  get  carried  to  the  cells  of 
the  bee.  When  she  deposits  an  egg  on  the  honey,  the  triungulin  glides  from 
the  body  of  the  bee  on  to  the  egg,  and  remains  perched  thereon  as  on  a  raft, 
floating  on  the  honey,  and  is  then  shut  in  by  the  bee  closing  the  cell.  This 
remarkable  act  of  slipping  on  to  the  egg  cannot  be  actually  witnessed,  but 
the  experiments  and  observations  of  the  French  naturalist  leave  little  room 
for  doubt  as  to  the  matter  really  happening  in  the  way  described.  The  egg 
of  the  bee  forms  the  first  nutriment  of  the  tiny  triungulin,  which  spends 
about  eight  days  in  consuming  its  contents;   never  quitting  it,  because  con- 


292  Beetles 

tact  with  the  surrounding  honey  is  death  to  the  httle  creature,  which  is 
entirely  unfitted  for  hving  thereon.  After  this  the  triunguhn  undergoes 
a  mouh  and  appears  as  a  very  different  creature,  being  now  a  sort  of 
vesicle  with  the  spiracles  placed  near  the  upper  part;  so  that  it  is  admirably 
fitted  for  floating  on  the  honey.  In  about  forty  days,  that  is,  towards  the 
middle  of  July,  the  honey  is  consumed,  and  the  vesicular  larva  after  a  few 
days  of  repose  changes  to  a  pseudo-pupa  within  the  larval  skin.  After 
remaining  in  this  state  for  about  a  month  some  of  the  specimens  go  through 
the  subsequent  changes,  and  appear  as  perfect  insects  in  August  or  Septem- 
ber. The  majority  delay  this  subsequent  metamorphosis  till  the  following 
spring,  wintering  as  pseudo-pupai  and  continuing  the  series  of  changes  in 
June  of  the  following  year;  at  that  time  the  pseudo-pupa  returns  to  a  larval 
form,  dififering  comparatively  little  from  the  second  stage.  The  skin, 
though  detached,  is  again  not  shed,  so  that  this  ultimate  larva  is  enclosed 
in  two  dead  skins;  in  this  curious  envelope  it  turns  round,  and  in  a  couple 
of  days,  having  thus  reversed  its  position,  becomes  lethargic  and  changes 
to  the  true  pupa,  and  in  about  a  month  subsequent  to  this  appears  as  a 
perfect  insect,  at  about  the  same  time  of  the  year  as  it  would  have  done 
had  only  one  year,  instead  of  two,  been  occupied  by  its  metamorphosis. 
M.  Fabre  employs  the  term  third  larva  for  the  stage  designated  by  Riley 
Scolytoid  larva,  but  this  is  clearly  an  inconvenient  mode  of  naming  the  stage. 
.  .  .  Meloe  is  also  dependent  on  Anthophora,  and  its  life-history  seems 
on  the  whole  to  be  similar  to  that  of  Sitaris;  the  eggs  are,  however,  not 
necessarily  deposited  in  the  neighborhood  of  the  bees'  nests,  and  the 
triungulins  distribute  themselves  on  all  sorts  of  unsuitable  insects,  so  that 
it  is  possible  that  not  more  than  one  in  a  thousand  succeeds  in  getting  access 
to  the  Anthophora  nest.  It  would  be  supposed  that  it  would  be  a  much 
better  course  for  these  bee-frequenting  triungulins  to  act  like  those  of  Epicauta, 
and  hunt  for  the  prey  they  are  to  live  on;  but  it  must  be  remembered  that 
they  cannot  live  on  honey;  the  one  tiny  egg  is  their  object,  and  this  appar- 
ently can  only  be  reached  by  the  method  indicated  by  Fabre.  The  history 
of  these  insects  certainly  forms  a  most  remarkably  instructive  chapter  in 
the  department  of  animal  instinct,  and  it  is  a  matter  for  surprise  that  it 
should  not  yet  have  attracted  the  attention  of  comparative  psychologists. 
The  series  of  actions  to  be  performed  once,  and  once  only,  in  a  lifetime  bv 
an  uninstructed,  inexperienced  atom  is  such  that  we  should,  a  priori,  have 
denounced  it  as  an  impossible  means  of  existence,  were  it  not  shown  that 
it  is  constantly  successful.  It  is  no  wonder  that  the  female  Meloe  produces 
five  thousand  times  more  eggs  than  are  necessary  to  continue  the  species 
without  diminution  in  the  number  of  its  individuals,  for  the  first  and  most 
important  act  in  the  complex  series  of  this  life-history  is  accomplished  by 
an  extremely  indiscriminating  instinct;    the   newly  hatched  Meloe   lias   to 


Beetles  293 

get  on  to  the  body  of  the  female  of  one  species  of  bee;  but  it  has  no  dis- 
crimination whatever  of  the  kind  of  object  it  requires,  and,  as  a  matter  of 
fact,  passes  with  surprising  rapidity  on  to  any  hairy  object  that  touches  it; 
hence  an  enormous  majority  of  the  young  are  wasted  by  getting  on  to  all 
sorts  of  other  insects;  these  larvae  have  been  found  in  numbers  on  hairy 
Coleoptera,  as  well  as  on  flies  and  bees  of  wrong  kinds;  the  writer  has  ascer- 
tained by  experiment  that  a  camel's-hair  brush  is  as  eagerly  seized,  and 
passed  on  to,  by  the  young  Meloe  as  a  living  insect  is." 

The  commonest  Eastern  species  of  blister-beetles  belong  to  the  genus 
Epicauta.  They  feed  when  adult  on  the  leaves  of  potato — being  therefore 
often  called  potato-beetles — and  on  the  pollen  of  goldenrod.  E.  pennsyl- 
vanica  is  uniformly  black;  E.  cinerea  is  grayish  black  or  even  ashy,  always 
with  the  margins  of  the  elytra  gray;  E.  vittata  (Fig.  401)  is  yellowish  or  reddish 
above,  with  head  and  prothorax  marked  with  black  and  with  two  black  stripes 
on  each  elytron.  In  Meloe  the  wings  are  lacking  and  the  elytra  short  and 
diverging;  M.  angusticollis ,  the  buttercup  oil-beetle,  i  to  f  inch  long, 
of  violaceous  color,  is  the  commonest  eastern  species.  In  the  west  the 
commonest  blister-beetles  are  metallic  green  and  blue  and  belong  to  the 
genus  Cantharis. 

Another  small  family  of  rarely  seen  heteromerous  beetles,  which,  how- 
ever, possess  an  extremely  interesting  and  wonderfully  specialized  life-history 
and  show  a  marked  degenerate  structure  due  to  their  parasitic  habits,  is 
the  Stylopidae,  or  wasp  parasites.  Indeed  these 
curiously  modified  beetles  difl'er  so  much  from 
all  the  other  Coleoptera  that  some  entomolo- 
gists look  on  them  as  composing  a  distinct  order 
which  these  naturalists  call  Strepsiptera.  The 
males  are  minute  with  large  fan-shaped  wings 
and  reduced,  short,  club-like  elytra.  The 
females  are  wingless  and  never  develop  bevond 

a  larval  or  grub-like  condition.     They  live    in     Fig.  403.-A  wasp  Po//5/r5  sp., 
°  -'  parasitized  by  (x)  Xeiws  sp. 

the  body  of  a  wasp   or  bee   (Fig.  403) — certain  (After  Jordan    and  Kellogg; 

foreign  species  parasitize  ants,  cockroaches,  and  slightly  enlarged.) 
other  insects — while  the  free-flying  males  live  from  only  fifteen  or  twenty  minutes 
to  a  day  or  two:  three  days  is  the  longest  observed  lifetime  of  active  adult 
existence!  The  youngest  larva  of  the  Stylopids — the  egg-laying  has  not 
been  observed — is  a  minute,  active,  six-legged  creature,  not  unlike  the  Meloid 
triungulin,  which  attaches  itself  to  the  larva  of  a  bee  or  wasp  and  burrows 
into  its  body.  There  it  Hves  parasitically,  meanwhile  undergoing  hypermeta- 
morphosis  in  that  after  its  first  moult  it  becomes  a  footless  maggot  or  grub. 
In  this  state  it  continues  until,  if  a  male,  it  pupates  in  the  host's  body  and 
issues  for  its  brief  active  adult  Ufe.     If  a  female,  there  is  no  pupation,  but 


294  Beetles 

when  the  host  larva  itself  pupates  the  Stylops  pushes  one  end  of  its  own 
body  out  between  two  abdominal  segments  of  the  host,  and  there  gives  birth 
alive  to  many  little  triunguHns.  How  the  triungulins  find  their  way  to 
their  bee-larva  hosts  is  not  very  clear,  but  they  probably  he  in  wait  in  flowers 
and  when  a  bee  comes  along  they  cHng  to  its  leg  and  are  thus  carried  to 
the  nest  where  the  larvae  are.  There  are  two  genera  of  Stylopidse  in  our 
country,  Xenos,  which  parasitizes  the  social  wasps,  Polistes,  and  Stylops, 
which  parasitizes  the  mining-bees,  Andrena.  The  triungulins  of  Xenos, 
being  born  in  a  community  nest,  can  simply  roam  about  over  the  brood- 
comb  until  they  they  find  a  wasp-larva  to  burrow  into. 

Rhynchophora. 

In  this  suborder  are  included  all  those  beetles  known  as  curculios,  wee- 
vils, bill-bugs,  and  snout-beetles  (excepting  the  pea-  and  bean  weevils,  see 
p.  281).  They  are  all  characterized  by  the  peculiar  prolongation  of  the 
front  of  the  head  into  a  beak  or  snout,  which  may  be  long,  slender  and 
curved,  or  straight,  short,  thick,  and  obtuse.  The  mouth-parts,  of  which  the 
small  sharp  jaws  are  the  conspicuous  feature,  are  situated  at  the  tip  of  the 
snout;  upper  lip  (labrum)  and  palpi  are  wanting.  The  antennae  arise 
from  the  sides  of  the  snout  and  are  angularly  bent  or  "elbowed"  in  the 
middle  and  end  in  a  knobbed  or  clavate  tip.  The  body  is  soHd  and  compact, 
usually  strongly  rounded  above,  and  many  species  are  thinly  or  thickly  cov- 
ered with  scales. 

Most  of  the  weevils  feed,  as  adults,  on  fruits,  nuts,  and  various  seeds, 
though  some  attack  stems  and  leaves,  and  others  hard  wood.  Many 
feign  death  when  disturbed,  folding  up  their  legs  and  head  and  lying 
inert  until  danger  is  past.  The  larvae  are  soft,  wrinkled,  white,  footless 
grubs  which  mostly  live  in  fruits,  nuts,  and  seeds.  The  larvae  and  adults 
of  the  important  family  Scolytidae,  variously  called  timber-beetles,  bark- 
borers,  or  engraver-beetles,  burrow  in  the  bark  and  wood  of  trees  living  or 
dead. 

The  principal  families  of  the  suborder  can  be  separated  by  the  following 
key: 

The  dorsum  of  the  last  segment  (pygidium)  of  the  male  divided  transversely,  so  that 
this  sex  appears  to  have  one  more  body-segment,  when  viewed  dorsally,   than 
the   female. 
Mandibles  with  a  scar  on  the  anterior  aspect. 

(Scarred  snout-beetles.)     Otiorhynchid.e. 

Mandibles  without  scar  on  the  anterior  aspect (Curculios.)     Curculionid-i:. 

Pygidium  of  both  sexes  undivided. 
Pygidium  vertical;    tibis  not  serrate. 

(Bill-bugs  and  gianary-weevils.)     Calandrid^. 
Pygidium  horizontal ;   tibiae  usually  serrate (B  ark-beetles.)     Scolytid^. 


Beetles  295 

The  scarred  snout-beetles,  Otiorhynchidae,  get  their  vernacular  name 
from  the  presence  of  a  distinct  little  scar  on  the  front  aspect  of  each  mandible. 
It  is  made  by  the  falling  off  of  a  mandibular  appendage  present  in  the  pupa. 
Most  of  these  beetles  are  covered  with  minute  scales,  much  like  those  of  the 
moths  and  butterflies,  which  give  them  often  a  bright  metallic  coloration. 
Several  species  of  the  family  are  injurious  to  fruits. 

The  imbricated  snout-beetle,  Epiccerus  imbricatiis,  J  inch  long,  dull 
silvery  white  with  darker  markings,  and  with  the  elytra  with  longitudinal 
lines  of  deep  pits,  has  the  posterior  ends  of  the  elytra  very  steep  and  cut  off 
almost  squarely  and  ending  in  a  pointed  process.  It  feeds  on  various  culti- 
vated plants,  as  garden  vegetables,  strawberries,  etc.,  and  gnaws  holes  in 
the  twigs  and  fruits  of  apple  and  cherry.  The  pitchy-legged  weevil, 
Otiorhynchus  ovatus,  ^  inch  long,  dark  brown  to  black  with  deeply  pitted 
thorax  and  striated  elytra,  with  deep  punctures  in  the  striae,  almost  egg- 
shaped  hind  body,  and  thorax  with  projecting  angle  on  each  side,  attacks  the 
roots  and  crowns  of  strawberry-plants,  and  also  the  leaves  of  apple-trees. 
Fuller's  rose-beetle,  Araniiges  julleri,  is  perhaps  the  most  familiar  species 
of  this  family,  as  it  attacks  garden  and  conservatory  roses,  and  in  Cali- 
fornia is  an  orange  pest  of  some  note.  It  is  \  inch  long,  oval,  smoky-brown, 
and  thinly  covered  with  scales;  its  "snout"  is  short  and  obtuse.  The  eggs 
are  laid  in  masses  in  concealed  places  on  rose-bushes, 
the  larvie  feeding  on  the  roots  of  the  bushes,  while  the 
adults  attack  the  leaves,  buds,  and  flowers.  The  beetles 
hide  during  the  day  on  the  under  side  of  the  leaves, 
and  can  readily  be  collected  and  destroyed. 

The  Curculionidae,  the  typical  curculios  and  weevils, 
compose  the  largest  and  most  important  family  of  the 
suborder,  comprising  over  600  species  of  North  Amer- 
ican  beetles,  and   including  many  seriously  destructive 

pests.      Such   enemies  of  the  fruit-grower  as  the  plum-   ^  ^, 

^         ,.  ,  ,  ^,  ,  ,  Fig.  404.— The  chest- 

curculio,   plum-gouger,    apple-weevil,   and    strawberry-       nut-weevil,    Balani- 

weevil,  and    such   a   destructive   pest   of   cotton  as  the       "'"  caryatrypes. 

boll-weevil    (for    the    study    and    combating   of   which       natural  sizeT' 

Congress  has  recently  appropriated  $250,000),  are  alone 

sufficient   to  give   this   family  a  high  rank  in   the   list  of  notorious  insect 

pests.     The  eggs  of  Curculionids  are  laid  singly  in  holes  bored  or  cut  by 

the  female  with   her  snout  in  stems  or  fruits  of  the   food-plant  and  pushed 

to  the  bottom  by  the  snout,  which  is  therefore  often  very  long  and  slender. 

The   nut-  and  acorn-weevils  of   the  genus  Balaninus  are  characterized  by 

their  possession  of  an  unusually  long,  slender,  curving  beak  (Fig.  404) ;   in 

the  females  this  beak  may  be  twice  as  long  as  the  rest  of  the  body;  in  the 

males  it  is  usually  about  the  length  of  the  body.     These  beetles  are  from 


296  Beetles 

^  to  I  inch  long,  clay-yellow  or  mottled  brownish,  and  lay  their  eggs  in 
chestnuts,  hazelnuts,  acorns,  walnuts,  hickory-nuts,  etc.  The  white,  yellow- 
headed,  maggot-like  larva  feeds  on  the  kernel,  and  is  full-grown  at  the 
time  the  nuts  drop.  It  either  lies  in  the  nut  over  winter  or  crawls  out  and 
into  the  ground,  where  it  pupates,  and  transforms  into  an  adult;  B.  rectus 
and  B.  quercns  are  common  acorn-weevils,  B.  caryatrypes  (Fig.  404)  a 
common  chestnut-weevil,  and  B.  nasicus  a  hickory-nut  weevil. 

The  genus  Anthonomus  includes  small  pear-shaped,  modestly  colored 
weevils  with  long  slender  snouts.  A.  qitadrigibbus,  the  apple-weevil,  ^  inch 
long,  dull  brown,  with  four  conspicuous  brownish-red  humps  on  the  hinder 
part  of  the  body,  lays  its  eggs  in  little  blackish-margined  holes  drilled  into 
apples;  the  white,  footless,  wrinkled,  brown-headed  larva  on  hatching  bur- 
rows into  the  core,  feeds  around  it,  ejecting  much  rusty-red  excrement,  and 
finally  pupates,  the  adult  weevil  gnawing  its  way  out  to  the  surface.  A .  sig- 
natiis,  the  strawberry-weevil,  blackish  with  gray  pubescence,  punctures 
the  buds,  laying  an  egg  in  each,  and  then  punctures  the  flower-pedicel  below 
the  bud,  so  that  it  drops  off;  the  larva  feeds  on  the  fallen  unopened  bud, 
changing  to  a  beetle  in  midsummer.  A.  grandis  is  the  notorious  boll- 
weevil  of  the  South,  which  has  made  its  way  since  1890  from  Mexico  into 
this  country  and  is  now  one  of  our  most  serious  insect  pests;  it  destroys  as 
much  as  ninety  per  cent  of  the  cotton-crop  in  badly  infested  localities.  The 
eggs  are  deposited  in  the  buds  and  bolls,  and  the  larva?  feed  on  seed  and 
shell,  pupating  inside  the  wall  of  the  boll,  through  which  the  issuing  beetle 
gnaws  its  way.     This  pest  seems  to  feed  only  on  cotton. 

Next  to  the  codlin-moth  and  San  Jose  scale  probably  the  most  notorious 
and    destructive    frviit-pest    is    the   plum-curculio,    Conotrachelus   nenuphar 

(Fig.  405),  a  small  beetle,  \  inch  long,  brown, 
and  with  four  small  elevated  excrescences  on 
the  hard  wing-covers.  The  beetles  hibernate 
in  rubbish,  such  as  accumulated  leaves,  about 
the  orchard,  and  come  out  in  early  spring  to  feed 
on  the  tender  buds,  leaves,  flowers,  and    even 

^  ^,        ,  ,.      green    bark.      When   the  plums  have   set,   the 

Fig.  40s. — The    plum-curcuho,   '^  .  ...  .       , 

ConStrachelus   nenuphar,  females  begm  to  deposit  their  eggs  m  them  by 

(After  photograph  by  Slinger-  driUing   a.  tiny  hole  and    pushing    an   egg  into 

,  en  arge  .  each.     Then  a  concentric  slit    is    cut    near  the 

hole  so  as  to  leave  the  egg  in  a  little  flap  in  which   the  tissue  is  so  injured 

that  the  rapid  growing  of  the  fruit  does  not   injure  the  delicate  egg  buried 

in  it.     The  whitish  larva  bores  in  until  it  reaches  the   stone  around  which 

it  feeds.      (The  larva  of  the   plum-gouger,  Coccotorus   sciitellaris ,  another 

destructive   Curculionid  pest   of  the  plum,   bores  into   the   stone.)     When 

the  larvae  are  full-grown  the  infested  plums  fall  to  the  ground,  and  the  larvae 


Beetles 


297 


crawl  out  and  into  the  soil  to  pupate.  The  adult  beetles  soon  issue  and 
hunt  up  hibernating  quarters.  The  plum-curculio  attacks  cherries,  and 
also  peaches,  nectarines,  and  apricots.  In  many  regions  of  this  country 
it  has  wholly  stopped  the  growing  of  plums.  Curiously  enough,  but 
fortunately,  this  pest  does  not  seem  to  be  able  to  maintain  itself  in  California, 
where  plum  (prune)  growing  is  one  of  the  chief  industries.  A  remedy  of 
some  effectiveness  is  to  jar  each  plum-tree,  under  which  a  sheet  has  been 
spread,  repeatedly  during  blossoming  and  fruit-setting  time.  The  curculios, 
alarmed  by  the  jarring,  fold  up  their  legs  and  snout  and  fall  to  the  ground 
(sheet),  where  they  feign  death.     This  feigning  can  be  turned  into  reality 


Fig.  406. — Larva  and  pupa  of  the  quince-curculio,  Conotrachelus  cratmgi.  (After  photo- 
graphs by  Slingerland;  at  left,  larva,  natural  size  and  enlarged;  at  right,  pupa  much 
enlarged.) 


by  any  one  of  various  means.  Excellent  "curculio-catchers"  consist  of 
wheelbarrows  on  each  of  which  is  mounted  a  large  inverted  umbrella  split 
in  front  to  receive  the  tree-trunk,  against  which  the  barrow  (with  a  padded 
bumper)  is  driven  with  force  enough  to  do  the  jarring.  All  fallen  plums  also 
should  be  promptly  gathered  and  burned  or  scalded  so  as  to  kill  the  larvae 
within. 

The  family  Calandridas  includes  about  eighty  North  American  species 
of  weevils,  of  which  several  are  common  and  famihar  under  the  names  of 
corn  bill-bugs  and  rice-  and  grain-weevils.  To  the  large  genus  Sphenophorus 
belong  the  species  known  as  corn  bill-bugs,  blackish,  brown,  or  rarely  gray 
in  color,  from  i  to  J  inch  long,  with  thick  and  hard  elytra  which  are 
ridged  and  punctured,  as  is  also  the  thorax.     By  day  they  hide  in  the  soil 


298 


Beetles 


at  the  base  of  young  corn-plants,  and  at  night  bore  little  round  holes  into 
their  stems.  The  larvae  live  in  the  stems  of  timothy,  sedges,  or  bulb-rooted 
grasses,  pupating  in  fall  or  early  spring.  To  the  genus  Calandra  belongs 
the  destructive  rice-w^eevil,  C.  oryza,  \  inch  long,  blackish  to  pale  chestnut, 
which  attacks  all  kinds  of  stored  grains  and  is  especially  injurious  in  the 
southern  states  to  rice,  and  the  granary- weevil,  C.  granaria,  ^  inch  long, 
dark  brown,  also  common  in  grain-bins.  Both  these  species  have  been 
widely  distributed  by  commerce,  and  by  their  rapid  multiphcation  and  the 
concealment  afforded   them    by  the  grain  often  attain  such  abundance  as 

to  cause  great  loss  in  mills,  breweries, 
and  elevators.  The  preventive  remedy 
is  cleanliness  and  the  rapid  removal  of 
the  stored  grain.  They  prefer  dark 
places,  therefore  a  flood  of  sunHght 
will  prevent  their  rapid  increase.  In 
bins  that  can  be  made  nearly  air-tight 
these  pests  may  be  killed  by  the  fumes 
of  carbon  bisulphide. 

One  may  often  see  in  the  woods  the 
curious  hieroglyphics  of  the  engraver- 
beetles  (Scolytidae).  Where  bark  has 
been  torn  from  a  tree  -  trunk  both 
the  exposed  trunk-wood  and  the  inner 
surface  of  the  stripped-off  bark  reveal 
the  tortuous  branching  mines  or  tunnels 
of  the   Scolytidae.     A  common   way   of 

„  .  1-     /-         making  these  tunnels  is  as  follows:    The 

Fig.   407. — ^The   quince -curculio,   Cono-  & 

trachelus  cratagi.  (After  photograph  beetles  (a  male  and  a  female  together) 
by  Slingerland;  natural  size  and  en-  burrow  from  the  outside  through  the 
larged.)  ,  .  ,  ,  ,       ,  „     T       • 

thick  rough  outer  bark,  usually  leaving 

a  little  betraying  splotch  of  fine  sawdust,  to  the  inner  live  bark  or  sap- 
wood;  here  the  pair  turn,  keep  to  this  Uve  sap-filled  region,  laying  their 
eggs  in  masses  or  scattered  along  a  tunnel.  Soon  the  larvae  hatch,  where- 
upon each  digs  a  tunnel  for  itself,  all  of  the  new  larval  mines  branching  out 
from  the  original  tunnel  made  by  the  parent  beetles.  When  full-grown 
the  larva  digs  a  cell  at  the  end  of  its  tunnel  and  pupates  in  it.  The  issuing 
beetle  finds  its  way  out  through  the  tunnels  and  is  soon  ready  to  begin  a  new 
mine.  But  there  is  much  variation  in  the  mining  habits  of  the  various  species. 
The  beetles  are  small,  often  microscopic,  the  larger  ones  rarely  more  than 
\  inch  long.  They  are  brown  to  blackish,  with  stout,  nearly  cylindrical 
hard  bodies,  the  hind  end  of  the  body  usually  obliquely  or  squarely  truncate, 
and  the  head  short,  bent  downward;  and  so  covered  by  the  thorax  as  to  be 


Beetles 


299 


almost  invisible  from  above.  The  larvK  are  white  and  footless  little  grubs 
with  very  strong  jaws.  The  family  includes  1 50  species  in  North  America,  and 
because  of  the  recently  awakened  interest  in  forestry  is  now  being  given  special 
attention  by  entomologists.  The  losses,  by  the  death  of  trees  and  the  rid- 
dling of  timber,  caused  by  these  obscure  little  insects  are  enormous.  Pinchot, 
chief  of  the  United  States  Bureau  of  J'orestry,  has  recently  estimated  the 
annual  forest  losses  caused  by  insects  to  be  $100,000,000,  and  most  of  the 
ravages  are  due  to  the  Scolytidae. 

Among  the  most  destructive  genera  are  Dendroctonus  and  Tomicus, 
each  with  numerous  species.  They  often  work  in  the  same  tree.  For 
example,  the  famous  Monterey  pines  of  California  are  attacked  by  Dendroc- 


FiG.  408. — Galleries  in  Monterey  pine,  with  larvas,  pupae,  and  adults  of  the  engraver- 
beetle,  Tomicus  plaslographus.  (Natural  size  except  the  single  beetle  outside, 
which  is  enlarged  three  times.) 


tonus  valens  in  the  lower  three  or  four  feet  of  the  trunk,  as  many  as  four 
hundred  individuals  (larvae,  pupae,  and  adults)  occurring  in  this  limited 
space  in  badly  infested  trees,  while  above  this  zone  on  up  to  the  top  of  the 
tree  are  the  mines  of  Tomicus  plaslographus  (Fig.  408),  from  thirty  to  forty 
pairs  burrowing  into  each  yard  of  trunk.  It  is  plain  that  such  a  combined 
attack  on  a  single  tree  means  death  to  it. 

The  ambrosia-beetles,  including  half  a  dozen  genera  and  many  species, 


300 


Beetles 


have  special  habits  which  make  them  comparable  in  some  ways  with  the 
social  wasps,  bees,  and  ants,  and  with  the  termites.  They  live  in  mines — 
the  "black  holes"  often  seen  in  timber — bored  into  the  heart-wood  of  sick 
or  dead  trees,  in  colonies  including  numerous  adults  and  many  larvae.  Their 
food  is  not  the  wood  of  the  tree,  but  consists  of  certain  minute  and  succulent 
bodies  produced  by  a  fungus  which  grows  on  the  walls  of  their  burrows. 
This  fungus  does  not  grow  there  by  chance,  but  is  "planted"  by  the  beetles. 
It  is  started  by  the  female  upon  a  carefully  packed  bed  or  layer  of  chips, 
sometimes  near  the  entrance  of  a  burrow,  in  the  bark,  but  generally  at  the 
end  of  a  branch  gallery  in  the  wood.  It  spreads,  or  is  spread,  from  this 
forcing-bed  to  the  walls  of  the  various  galleries  and  chambers  of  the  mine. 
The  young  larvae  nip  off  the  tender  tips  of  the  fungus  stalks  "as  calves  crop  the 
heads  of  clover,"  but  the  older  larvae  and  adult  beetles  eat  the  whole  structure 
down  to  its  base,  from  which  new  hyphae  soon  spring  up  afresh.  The  fungus 
is  suitable  for  the  insects  only  when  fresh  and  juicy:  if  allowed  to  ripen,  the 
tender  protoplasm  is  shut  up  in  spores,  and  the  galleries  are  soon  filled  to 
suffocation  with  these  spores  and  the  ramifying  mycelial  threads.  Indeed 
the  colony  of  ambrosia-beetles — ambrosia  being  the  name  applied  to  the 
tender  fungus  food — is  often  overwhelmed  and  destroyed  by  the  quick 
growth  of  their  garden-patch.  If  anything  happens  to  interrupt  the  constant 
feeding  on  and  cutting  back  of  the  fungus,  the  colony  is  almost  always 
destroyed 


CHAPTER  XIII 
THE  TWO-WINGED  FLIES  (Order  Diptera) 


EXT  to  the  name  ''bug"  there   is   no   other   name  so 
popular  in  point  of  miscellaneous  application  to  insects 
as  "fly."     This  looseness  of  popular   nomenclature 
may  be  largely  due  to  the  fact  that  entomologists  them- 
selves apply  the  term  "fly  "  in  several  compound  words, 
as  butterfly,  alder-fly,  caddis-fly,  May-fly,  saw-fly,  and 
the  Hke,  to  widely  differing  kinds  of  insects.     Used  as 
a  simple  word,  however,  by  fly  an  entomologist  means 
some  species  of  the  order  Diptera.     The  various  kinds  of 
true  flies  have  of  course  special  names,  as  mosquitoes, 
midges,   punkies,    gnats,   or    as    in    the    compounds 
horse-flies,  bee-flies,  flower-flies,  robber-flies,  etc. 
The  order  Diptera  is  so  large  and  includes  insects  of  such  widely  differing 
form  and  habit  that  it  is  difficult  to  formulate  any  general  account  of  it.     The 
gj—ju  .  name  itself  is  derived  from  the  most  conspicuous 

structural  condition  of  flies,  namely,  their  two- 
winged  state.  All  Diptera  have  but  a  single 
pair  of  wings,  if  any;  a  few  are  wingless.     The 


tiG.   409.  Fig.  410. 

Fig.  409. — Mouth-parts  of  a  female  mosquito,  Culex  sp.  lep.,  labrum-epipharynx;  md., 
mandible;  mx.L,  maxillary  lobe;  ntx.p.,  maxillary  palpus;  hyp.,  hypopharynx;  li., 
labium;  gl.,  glossa;    pg.,  paraglossa. 

Fig.  410. — Mouth-parts  of  the  house-fly,  Miisca  domestica.  lb.,  labrum;  mx.p.,  maxil- 
lary palpi;    li.,  labium;    la.,  labellum. 

hind  wings  of  other  forms  are  replaced  by  a  pair  of  strange  little  structures 

301 


302 


The  Two-winged  Flies 


Fig.  411.  —  Head,  antennae, 
and  beak  of  mosquito,  lat- 
eral aspect. 


called  balancers,  or  halteres,  whose  use  seems  to  be  chiefly  that  of  orienting 
or  directing  the  fly  in  its  flight.  The  possession  of  these  balancers 
is  a  certain  diagno.stic  character  in  distinguishing  Diptera  from  all 
other  insects.  The  wings  are  membranous  and  usually  clear,  and 
supported  by  a  few  strong  veins.  No  flies  can  bite  in  the  sense 
of  the  chewing  or  crushing  biting  common  to  beetles,  grasshoppers,  and 
other  insects  with  jaw-like  mandibles,  but  some  have  mandibles  elongate, 
slender,  and  sharp-pointed,  so  that  they  act  as  needles  or  stylets  to  make 
punctures  in  the  flesh  of  animals  or  tissues  of  plants.  The  great  majority 
of  flies,  however,  have  no  mandibles  at  all  and  no  piercing  beak,  but  lap  up 

liquid  food  with  a  curious  folding  fleshy  proboscis, 
which  is  the  highly  modified  labium  or  under-lip. 
They  feed  on  flower-nectar,  or  any  exposed  sweet- 
ish Hquid,  or  the  juices  of  decaying  animal  or 
plant  substance.  To  take  solid  food  as  the 
house-fly  does  from  a  lump  of  sugar,  the  solid 
has  to  be  rasped  off  as  small  particles  which  are 
either  dissolved  or  mixed  in  a  salivary  fluid 
that  issues  from  the  fleshy  tip  of  the  proboscis. 

All  the  Diptera  have  a  complete  metamorphosis,  the  young  hatching 
from  the  egg  as  footless  and  often  headless  larvae  (maggots,  grubs),  usually 
soft  and  white,  and  in  many  cases  ob- 
taining food  osmotically  through  the 
skin.  The  life-history  is  usually  rapid, 
so  that  generation  after  generation  suc- 
ceed one  another  quickly.  Thus  it  may 
be  true,  as  an  old  proverb  says,  that 
a  single  pair  of  flesh-flies  (and  their 
progeny)  will  consume  the  carcass  of 
an  ox  more  rapidly  than  a  lion.  The 
pupae  of  the  more  specialized  flies  are 
concealed  in  the  thickened  and  darkened 
last  larval  moult,  the  whole  puparium 
looking  much  like  a  large  elliptical  brown 
seed. 

The   Diptera   include    the    famihar 
house-flies,   flesh-flies,    and    bluebottles 

of  the  dwelling  and  stables;  the  horse-flies  and  greenheads,  that  make 
summer  hfe  sometimes  a  burden  for  horses  and  their  drivers;  the  buzzing 
flower-  and  bee-flies  of  the  gardens;  the  beautiful  little  pomace-flies  with 
their  brilliant  colors  and  mottled  wings  that  swarm  like  midges  about 
the  cider-press  and  faUen  and  fermenting  fruit;    the  bot-flies,  those  disgust- 


FiG.  412. — The  blow-fly,  Cclliphoraery- 
throcephala.     Larva,  pupa,  and  adult. 


The  Two-winged  Flies  303 

ing  and  injurious  pests  of  horses,  cattle,  rabbits,  rats,  etc. ;  the  fierce  robber- 
flies  that  prey  on  other  insects,  including  their  own  fly  cousins;  the  midges 
and  gnats,  that  gather  in  dancing  swarms  over  pastures  and  streams;  the 
black-flies  and  punkies,  dreaded  enemies  of  the  trout-fisher  and  camper; 
and,  worst  of  all,  the  cosmopolitian  mosquito,  probably  the  most  serious  insect 
enemy  of  mankind.  Only  in  recent  years  have  we  come  to  recognize  the 
mosquito's  real  capacity  for  mischief.  Annoying  and  vexatious  they  have 
always  everywhere  been,  by  day  and  night,  from  tropics  to  pole,  from  the 
salt  marshes  by  the  sea  to  the  alpine  lakes  on  the  shoulders  of  the  mountain- 
peaks.  But  that  the  mosquito-bite  not  only  annoys  but  may  kill,  by  infect- 
ing the  punctured  tissues  with  the  germs  of  malaria  or  yellow  fever  or  filari- 
asis,  three  of  the  most  wide-spread  and  fatal  diseases  of  man — this  alarming 
fact  is  a  matter  which  has  come  to  be  really  recognized  only  recently,  and 
the  general  recognition  of  which  has  given  to  the  practical  study  of  insects 
an  importance  which  years  of  warning  and  protesting  by  economic  entomol- 
ogists have  been  wholly  unable  to  do. 

The  Diptera  include  about  7,000  known  species  in  North  America,  thus 
ranking  among  the  principal  orders  of  insects  in  degree  of  numerical  represen- 
tation in  this  country.     About  50,000  species  are  known  in  the  whole  world. 

The  order  may  be  separated  into  certain  principal  subdivisions  by  the 
following  table: 

Living  as  external  parasites  on  mammals,   birds,   or  honey-bees;    body  flattened  and 
often  wingless;    the  young  born  alive  as  larvae  nearly  ready   to  pupate. 

Suborder  Pupipara  (see  p.  351). 
Not  living  on  the  bodies  of  other  animals;    young  usually  produced  as  eggs. 

Suborder  Diptera  genuina  (see  p.  304). 

Antennae  with  numerous  (more  than  five)  segments.  .Section  Nematocera  (see  p.  304). 

Antennae  with  not  more  than  five  segments,  usually  with  three,  the  third  sometimes  annu- 

lated,  showing  it  to  be  a  compound  segment,  i.e.,  composed  of  several  coalesced 

segments Section   Brachycera   (see   p.    327). 

Third  segment  of  antennae  annulated,  showing  it  to  be  composed  of  several  coalesced 

segments (see    p.    327). 

Antennae  consisting  of  four  or  five  distinct  segments (see  p.  330). 

Antennae  with  but  three  segments  (rarely  less),  the  third  segment  with  or  without  a 
style  or  bristle (see  p.  332). 

Of  the  two  suborders  the  smaller  one,  the  Pupipara,  including  certain 
strangely  speciahzed  and  degraded  parasitic  flies,  will  be  considered  last.  Of 
he  first  suborder,  the  Diptera  genuina,  the  various  famihes  of  small  midge- 
and  mosquito-Hke  flies  composing  the  section  Nematocera  (flies  with  slender 
several-segmented  antennas)  will  be  discussed  first,  as  they  are  believed  by 
entomologists  to  be  the  more  generalized  or  simpler  flies. 


304  The  Two-winged  Flies 

Of  this  section  the  mosquitoes,  black  flies,  and  punkies  are  perhaps  best 
known  because  of  the  annoyance  and  irritation  caused  by  their  "bites," 
that  is,  the  punctures  made  by  the  sharp  beak  of  the  females  in  their  blood- 
sucking forays.  But  the  swarms  of  dancing  midges  and  the  sprawhng  long- 
legged  crane-flies,  or  leather-jackets,  are  not  unfamiliar  members  of  this  group. 
In  addition  there  belong  here  a  few  famiHes  of  flies  httle  known  but  possessed 
of  most  interesting  habits  and  form. 

KEY  TO  FAMILIES  OF  NEMATOCERA. 

(The  references  to  the  names  and  character  of  the  veins  in  the  wings  which  occur  in 
this  and  other  keys  used  in  this  chapter  may  be  understood  by  a  comparison  of  the 
venation  of  the  specimen  being  examined  with  Fig.  18,  and  with  the  figures  of  the 
venation  of  various  families,  as  Figs.  425,  436,  444,  etc.) 

A.      Antennae  slender,  longer  than  thorax;    usually  nearly  as  long  as  body  or  longer; 
legs  long  and  slender,  and  abdomen  usually  so. 

B.      Very  small  moth-like  flies,  with  body  and  wings  hairy;   wings  with  9-1 1  longi- 
tudinal veins,  but  no  cross-veins  except  sometimes  near  the  base  of  the  wing. 

(Moth-like  flies.)     Psychodid^. 
BB.  Not  as  above. 

C.  Wings  with  a  network  of  line  vein-like  lines  near  the  outer  and  hinder 

margins  in  addition  to  the  regular  (heavier)  venation. 

(Net-winged  midges.)     Blepharocerid^. 
CC.         The  margin  of  the  wings  and  the  veins  fringed  with  scales. 

(Mosquitoes.)     Culicid^. 
CCC.      With  a  distinct  V-shaped  suture  on  the  back  of  the  thorax. 

(Crane-flies.)      Tipulid^, 
CCCC.  Without  distinct  V-shaped  suture  on  the  back  of  the  thorax. 

D.      Anal  veins  entirely  wanting;    medial   vein  wanting  or  at  most 
represented  by  a  single  unbranched    fold. 

(Gall-gnats.)     Cecidomyiid^. 

DD.  Anal  veins  present  or  represented  by  folds;  medial  vein  present 

or  at  least  represented  by  a  fold  which  is  usually  branched. 

E.       Ocelli    present;     hgs    slender    and    with    greatly    elongate 

ccxse  (basal  segment). .  .  (Fungus-gnats.)     Mycetophilid^. 

EE.  Ocelli  absent. 

F.      Wing-veins  well  developed  in  all  parts  of  the  wing. 

(Dixa-flies.)     DixiD^. 
FF.    Wing-veins    much    stouter    near    the    costal    (front) 
margin  of  the  wing  than  elsewhere. 

(Midges.)      Chironomid^. 
AA.  Antennse  shorter  than  the  thorax  and  rather  stout. 

B.      OcelH  present (March-flies.)     Bibionid^. 

BB.  Ocelli  absent;    wings  very  broad (Buffalo-gnats.)     Simuliid^. 

Of  the  ten  families  included  in  the  above  key  the  members  of  five  pass 
the  young  stages,  larval  and  pupal,  in  fresh  water;  of  the  members  of  two 


The  Two-winged  Flies 


305 


some  have  aquatic  immature  stages  and  some  terrestrial;  while  the  larvae 
and  pupaj  of  all  the  members  of  the  remaining  three  live  in  plants  or  in  the 
ground,  none  being  aquatic. 

Best  known  of  the  aquatic  famihes,  and  indeed  of  the  whole  suborder, 
is  the  mosquito  family,  the 
Culicidc'e.  While  the  different 
kinds  of  mosquitoes  are  much 
alike,  so  much  so  indeed  that 
most  of  us  are  quite  content  if 
we  can  determine  an  insect  to  be 
a  mosquito  without  carrying  the 
identification  farther,  there  are 
known  in  the  world  at  least  300 
different  mosquito  species,  rep- 
resenting two  dozen  distinct 
genera.  In  North  America 
nearly  60  species  are  already 
known,  representing  10  genera, 
and  new  ones  are  being  found 
constantly.  In  the  family  Culi- 
cida;  are  included  two  distinct 
general  types  of  mosquito,  one 
with  mouth-parts  forming  a  long, 
slender,  sucking  proboscis,  pro- 
vided with  sharp,  needle-like 
stylets  for  piercing  (Fig.  411),  the 
other  with  the  mouth-parts  short 
and  better  adapted  for  lapping 
or  sucking  up  freely  exposed 
liquids.  The  latter  type  of 
mouth  is  possessed  by  but  two 
genera,  all  the  others  being 
piercers  and  blood  suckers  (in 
the  female  sex).  Of  these  pierc- 
ing genera  three  are  of  especial 
importance  and  interest  to  us 
because  of  their  abundance  and 

their  definitely  determined  relation  to  the  development,  incubation,  and  dis- 
semination of  certain  serious  diseases  of  man.  These  three  genera  are  Culex, 
Stegomyia,  and  Anopheles.  To  Culex  belong  the  great  majority  of  familiar 
mosquitoes  which  pursue  and  harass  us  with  their  songs  and  bites;  to  Stego- 
myia (and  Culex)  belong  the  mosquitoes  held  responsible  for  the  dissemination 


Fig.  413. — The  life-history  of  a  mosquito, 
Culex  sp  A  small  raft  of  eggs  is  shown  on 
the  surface  of  the  water,  several  larvae 
("wrigglers"),  long  and  slender,  and  one 
pupa  ("tumbler"),  large-headed,  are  shown 
in  the  water,  and  an  adult  in  the  air  above. 
(From  life;  much  enlarged.) 


306  The  Two-winged  Flies 

of  yellow  fever  and  filariasis,  and  to  Anopheles  belong  the  malaria  breeding 
and  distributing  mosquitoes. 

All  the  mosquitoes  agree  in  having  strictly  aquatic  immature  stages.  The 
eggs  are  laid  on  the  surface  of  standing  or  slowly  moving  water,  usually 
fresh,  although  several  species  breed  abundantly  and  probably  exclusively 
in  brackish  water.  These  eggs  are  in  small  one-layered  packets  or  rafts  (usual 
in  Culex)  (Fig.  413)  or  are  scattered  singly  (in  Stegomyia  and  Anopheles)  (Fig. 
414)  and  hatch  in  from  one  to  four  days,  varying  with  the  species,  and  in 
the  same  species  with  the  temperature  and  hght 
conditions.  The  water  oviposited  on  may  be,  for 
Culex,  that  of  a  pond,  a  pool,  or  any  temporary 
puddle,  or  even  that  in  an  exposed  trough,  barrel, 
pail,  or  can.  With  Anopheles  only  natural,  usually 
Fig.  414.— The  eggs  of  permanent,  pools  are  selected.  I  have  found  the 
Anopheles  sp.  (After  gggg  of  Culex  incidens  on  the  surface  of  a  bubbhng 
Giles;  much  enlarged.)  g^^^^.^pj-jng  jn  CaHfornia,  and  of  Stegomyia  in  water 
held  in  sUght  depressions  in  a  number  of  ship's  metal  parts  in  Samoa. 
The  brackish-water  species  of  Culex  usually  lay  their  eggs  on  the  small 
clear  pools  scattered  through  the  marshes.  A  few  entomologists  have 
recorded  their  belief,  based  on  various  indirect  observations,  that  the  eggs 
of  Anopheles  at  least  may  be  deposited  on  the  soil,  but  no  direct  proof  of 
this  is  yet  on  record. 

The  larvs  (Figs.  413  and  415)  of  mosquitoes  are  the  familiar  wrigglers  of 
ponds  and  ditches.  The  long,  slender,  squirming  body,  with  its  forked  posterior 
extremity  and  thick  head  end,  is  thoroughly  characteristic.  The  head  is 
provided  with  a  pair  of  vibratile  tufts  or  brushes  of  fine  hairs  which  are 
kept,  most  of  the  time,  in  rapid  motion,  creating  currents  of  water  setting 
toward  the  mouth,  and  thus  bringing  to  it  a  constant  supply  of  food,  which 
consists  of  organic  particles  and  microscopic  animals.  Breathing  is  accom- 
plished by  the  wrigglers  coming  to  the  surface  and  hanging  head  downward 
from  it  with  the  open  tip  of  the  respiratory  tube,  one  of  the  prongs  of  the 
posterior  forking  of  the  body,  projecting  just  through  the  surface  film.  If  a 
mosquito  wriggler  is  prevented  from  coming  to  the  surface,  or  if,  once  there,  it 
finds  some  impediment  which  restrains  it  from  getting  its  respiratory  tube 
into  connection  with  the  free  air  above  the  surface,  it  will  drown.  And 
this  fact  partly  explains  the  fatal  effectiveness  of  a  film  of  kerosene  spread 
over  the  surface  of  a  pool  in  which  mosquitoes  are  breeding.  The  larval 
stage  lasts  from  one  to  four  weeks,  varying  in  different  species  and  also 
varying  in  the  case  of  each  species  at  different  seasons  and  under  different 
conditions  of  food-supply,  temperature,  and  light.  Larva?  of  Culex  have 
lived  in  breeding-jars  in  my  laboratory  for  three  months.  The  larvae  moult 
twice,  and  on  the  third  casting  of  the  skin  appear  as  active,  non-feeding 


The  Two-winged  Flies  307 

pupae  (Figs.  413  and  415)  with  thick,  broad  head  end  (the  thick  part  includes 
thorax  and  head)  and  slender,  curving  abdomen,  bearing  two  conspicuous 
swimming-iiaps  at  the  tip.  The  pupa  rests  at  the  surface  of  the  water  with 
its  two  short  horn-like  respiratory  tubes,  which  rise  from  the  dorsum  of  the 
thorax,  extending  through  the  surface  film  to  the  air  above.  When  dis- 
turbed it  swims  swiftly  down  into  the  water  by  quick  bendings  or  flappings 
of  the  abdomen  with  its  terminal  flaps.  The  pupal  stage  lasts  from  two  to 
five  days,  with  comparatively  little  variation  beyond  these  extremes. 

The  adults  issue  through  a  longitudinal  rent  in  the  back  of  the  pupal 
cuticle,  and  while  drying  their  wings,  legs,  and  body  vestiture  rest  on  the 
surface  of  the  water,  often  partly  supported  by  the  floating  discarded  skin. 
The  two  wings  are  long  and  narrow,  the  legs  long  and  slender,  the  thorax 
humped  with  the  small  head  hanging  down  in  front  and  the  slender  sub- 
cylindrical  abdomen  depending  behind.  The  body  is  clothed  with  scales,  as 
are  the  veins  of  the  wings,  and  on  the  scales,  which  are  of  different  shapes 
and  sizes  on  different  parts  of  the  body,  and  vary  in  different  species,  depend 
the  colors  and  pattern,  often  striking  and  beautiful,  just  as  all  the  color  pat- 
terns of  the  butterflies  and  moths  are  produced  by  a  covering  over  body  and 
wings  of  similar  scales.  The  males  of  all  mosquitoes  differ  from  the  females 
in  having  the  slender,  many-segmented  antennas  provided  with  many  long 
fine  hairs  arranged  in  whorls  and  combining  to  give  the  antennae  a  bushy  or 
feathery  appearance.  .  These  hairs,  as  has  been  proved  by  experiment  and 
histologic  study,  are  a  part  of  an  elaborate  auditory  apparatus,  their  special 
function  being  to  be  set  into  vibration  when  impinged  on  by  sound-waves  of 
certain  rates  of  vibration,  and  to  transmit  this  vibration  to  a  complex  nervous 
organ  in  the  second  antennal  segment  (Figs.  56  and  57).  The  males,  while 
having  a  long,  slender,  sucking-proboscis,  do  not  possess  the  piercing  sty- 
lets characteristic  of  the  female,  and  hence  are  not  blood-suckers,  but  prob- 
ably feed,  if  at  all,  on  the  nectar  of  plants  or  on  other  exposed  liquids.  The 
females  suck  blood  when  they  can  get  it,  but  in  Heu  of  this  animal  fluid 
feed  on  the  sap  of  plants.  In  experimental  work  in  the  laboratory  cut 
pieces  of  banana  are  provided  the  imprisoned  adult  mosquitoes. 

At  this  writing  about  fifty  species  of  Culex,  one  species  of  Stegomyia,  and 
four  species  of  Anopheles  have  been  found  in  this  country.  These  three 
genera  may  be  distinguished  by  the  following  key: 

Palpi  (the  mouth-feelers  projecting  by  the  side  of  the  proboscis)  long  in  both  male  and 

female,  about  as  long  as  the  proboscis Anopheles. 

Palpi  as  long  as  proboscis  in  male,  but  only  one-third  as  long  in  female. 

Scales  on  the  head  narrow  and  curved Culex. 

Scales  on  the  head  flat  and  broad Stegomyia. 

Our  particular  interest  in  being  able  to  distinguish  these  genera  lies,  as 
already  said,  in  the  special  relation  which  their  members  bear  to  certain 


3o8 


The  Two-winged  Flies 


wide-spread  and  serious  human  diseases.  The  role  played  by  mosquitoes 
in  the  breeding  and  dissemination  of  the  microscopic  germs  of  malaria  has 
been  so  well  exploited  in  newspapers  and  magazines  that,  although  a  matter 
of  comparatively  recent  determination,  it  is  already  common  knowledge,  at 
least  in  its  more  general  outline.  For  a  somewhat  detailed  account  of  the 
etiology  of  the  diseases  known  to  be  disseminated  by  mosquitoes,  including 
the  exact  relation  of  the  mosquito  host  to  the  disease-germs,  see  Chapter 
XVIII  of  this  book.  It  is  sufficient  to  say  here  that  the  malarial  germs  seem 
to  live  parasitically  in  and  be  disseminated  by  the  various  species  of  Ano- 
pheles only,  the  yellow- fever  germs  only  by  the  species  Stegomyia  jasciata,  and 
the  minute  worms  of  filariasis  by  the  same  species  and  two  or  three  tropical 
forms  of  Culex,  while  the  score  and  more  of  North  American  species  of 


Fig.  415. — A  malaria-carrying  mosquito,  Anopheles  maculipennis ;  larva  at  left,  in 
middle  two  eggs  below  and  pupa  above,  male  adult  at  right.  (From  life;  much 
enlarged.) 

Culex  compose  most  of  the  hordes  of  piercing  and  blood-sucking  mosqui- 
toes which  in  so  many  localities  make  life  distressful.  Stegomyia  jasciata  is 
found  in  this  country  only  in  the  Gulf  states.  In  our  colonies,  the  Hawaiian 
and  American  Samoan  Islands,  I  have  found  it  to  be  the  most  abundant  mos- 
quito species,  although  yellow  fever  is  yet  unknown  in  these  islands.  But 
it  seems  not  improbable  that,  with  the  cutting  of  a  canal  through  the  Isthmus 
of  Panama  so  that  ships  can  sail  directly  from  the  West  Indies  to  Hawaii 
continuously  within  the  tropics,  Stegomyia  individuals  infested  with  yellow- 
fever  germs  might  be  readily  carried  to  our  tropical  Pacific  colonies.  Such 
a  possible  contingency  should  at  least  be  had  in  mind  by  those  charged  with 
the  responsibility  of  public-health  affairs  in  Hawaii  and  Samoa.  Stegomyia 
is  already  terrible  enough  in  its  disease-spreading  capacity  in  unfortunate 
Samoa,  as  explained  in  Chapter  XVIII,  the  frightful  scourge  elephantiasis, 


The  Two-winged  Flies 


3^9 


an  incurable  and  hideously  deforming  kind  of  filariasis,  from  which  quite 
one-third  of  the  natives  of  Samoa  suffer,  being  disseminated  chiefly  (so 
far  as  our  present  knowledge  permits  us  to  affirm)  by  mosquitoes  of  the 
species  Stegomyia  fascia ta. 

With  a  few  English  investigators  and  our  own  government  and  state 
entomologists  in  the  lead,  a  great  campaign  is  being  waged  against  mos- 
quitoes. Despite  the  hosts  of  the  enemy,  its  great  capacity  for  providing 
new  individuals  to  supply  the  places  of  the  fallen,  i{s  effective  means  of 
locomotion,  and  its  easily  managed  de- 
partment of  commissary,  local  foraging 
being  exclusively  relied  on  for  sustain- 
ing its  armies,  we  are  making  headway 
against  it.  Our  modes  of  attack  are 
various:    by  draining  swamps,  ponds, 


Fig.  416.  Fig.  417. 

Fig.  416.— a  short-beaked  mosquito,  Corethra  sp.     (From  life;    four  times  natural  size. 
Fig.  417. — Pupa   (at  left)  and  larva   (at   right)  of  short-beaked  mosquito,  Corethra  sp. 
(From  life;    six  times  natural  size.) 

and  puddles  we  restrict  the  multipHcation  of  these  pests,  and  rid  particular 
localities  of  them  altogether;  by  introducing  into  ponds  and  pools  which 
cannot  be  drained  substances,  as  kerosene,  etc.,  which  are  poisonous  to  mos- 
quitoes, we  kill  them  in  their  adolescence;  by  encouraging  and  disseminating 
their  natural  enemies,  such  as  dragon-flies,  we  pursue  them  in  their  own 
elements,  water  and  air.  Mosquitoes  do  not  fly  far;  when  abundant  in  a 
locality,  breeding-places  are  to  be  looked  for  close  at  hand.  The  open  rain- 
water barrel,  a  little  puddle  by  the  lawn  hydrant,  a  cistern  with  unscreened 
openings,  all  of  these  are  welcome  invitations  to  the  mosquito  to  come  and 
rear  a  large  family.     Put  close  screen  tops  over  water  in  cisterns  and  barrels; 


3 


lO 


The  Two-winged  Flies 


leave  no  standing  puddles  in  the  back  yard  or  decorative  lily-pools  in  the 
front;  pour  kerosene  on  the  surface  of  ponds  and  ditches  in  the  neighbor- 
hood, and  the  mosquito  problem  for  localities  not  adjacent  to  swamps  and 
marshes  is  nearly  solved.  Where  the  problem  includes  swamps  larger 
measures  must  be  undertaken,  community  effort  may  be  necessary,  and  the 
rhunicipal  or  county  administration  called  on  to  take  official  action.  But 
when  it  is  remembered  that  aboHshing  the  mosquito  pest  means  doing  away 
with  malaria,  and  in  the  subtropic  and  tropic  region  with  yellow  fever  and 
filariasis,  no  pains  will  seem  too  troublesome,  no  expense  too  large  in  this 
warfare  of  man  against  mosquitoes. 


Fig.  418.  Fig.  410. 

Fig.  418. — Scales  on  the  wings  of  Culex  fatigans.     (After  Theobald;   greatly  magnified.) 
Fig.  419. — A  midge,  male,  Chironomiis  sp.     (From  life;    much  enlarged.) 


Looking  not  unlike  mosquitoes  are  the  larger  species  of  the  family  Chiro- 
nomidae,  whose  members  are  popularly  known  as  midges  and  punkies,  the 
name  blood-worm  being  applied  to  the  reddish  aquatic  larvae  of  certain 
species.  Like  the  mosquitoes,  the  males  are  distinguished  from  the  females  by 
their  very  bushy  or  feathery  antennae,  but,  unlike  the  mosquitoes,  the  females, 
except  in  the  case  of  the  minute  punkies  or  "no-see-ums"  of  the  New  Eng- 
land and  Canadian  mountains  and  forests,  and  their  near  relatives  in  the 
western  forests,  are  not  blood-suckers.  The  midges  are  particularly  notice- 
able in  "dancing-time,"  that  is,  when  they  collect  in  great  swarms  and  toss  up 
and  down  in  the  air  over  meadows,  pastures,  and  stream  sides. 

The  larvae  (Fig.  420)  of  most  species  are  aquatic,  some  of  them  forming 
small  tubular  cases,  as  caddis-fly  larvae  do,  and  most  oi  them  being  distinctly 
reddish  in  color.  They  wriggle  about  in  the  slime  and  decaying  leaves  at 
the  bottom  of  ponds  or  lakes,  feeding  on  vegetable  matter.  The  pupae 
(Fig.  421)  are,  like  those  of  the  mosquitoes,  active,  although  of  course  non- 
feeding,  and  are  provided  with  two  bunches  of  fine  hair-like  tracheal  gills 
on  the  dorsum  of  the  thorax,  or  with  a  pair  of  short  club-shaped  processes 


The  Two-winged  Flies 


311 


which  have  a  sort  of  sieve-like  skin.     In  both  cases  the  pupa  breathes  the 

oxygen  which  is  mixed  with  water  and  is  thus  not 

compelled,  as  are  the  mosquito  pupae,  to  come  to  the 

surface  for  air.     The  larvae  of  the  genus  Ceratopogon 

and  its  alhes,  which  include  the  fiercely  biting  and 

blood-sucking  httle  punkies  (Fig.  422),  so   irritating 

to   the   fisherman   and  hunter  in  the  north   woods, 


Fig.  420.  Fig.  421. 

Fig.  420. — Larva  of  a  midge,  Chironomus  sp.     (From  life:    natural  length  t  inch.) 
Fig.  421. — Pupa  of  midge,  Chironomus  sp.     (From  life;    natural  length  \  inch.) 

live,  according   to  Comstock,  "under  the  bark  of  decaying  branches,  under 
fallen  leaves,  and  in  sap  flowing  from  wounded  trees. " 

Running  and  half  flying  about  over  the  spray- wet  rocks  and  on  the  surface 
of  the  smaller  tide-pools  between  tide-lines  on  the  ocean  shore  near  Mon- 


FiG.  422.  Fig.  423. 

Fig.    422. — Mouth-parts   of   a   female    "punkie,"   Ceratopogon   sp.      lb.,    labrum;    md., 

mandible;  «;x.,  maxilla;  ?«:x:./.,  maxillary  lobe;  m^x;./).,  maxillary  palpus;  //.,  labium; 

p.g.,   paraglossa;    hyp.,   hypothorax. 
Fig.  423. — The  tide-rock  fly,  Eretmoptera  browni.     (Natural  length  ^  inch.) 


terey,  California,  may  be  seen  in  the  winter  months  many  small,  long-legged, 
spider-Hke  flies  (Fig.  423)  whose  wings  are  reduced  to  mere  oar-like  veinless 
rudiments.  The  larvae  and  pups  live  submerged  in  the  salt  water  of  the 
outer  and  most  exposed  tide-pools,  where  the  ocean  water  is  held  in  shallow 
depressions  in  the  rocks,  and  is  changed  many  times  daily  by  the  dashing 
of  the  waves.     Where  the  flies  go  when  the  tide  is  in  and  these  rocks  are 


312 


The  Two-winged  Flies 


either  whouy  submerged  or  at  least  constantly  dashed  over  by  the  breaking 
waves,  I  have  not  been  able  to  determine;    but  the  larvae  and  pupje  cling 


Fig.  424. 


Fig.  424.- 
Fig.  425.- 


FiG.  425. 
(Four  times  natural  size.) 


-A  black-fly,  Simuliiim  sp. 

-Diagram  of  wing  of  black-fly,  Simnliitm,  showing  venation. 


tight  and  secure  in  their  rock  basins  to  small  but  strong  silken  nets  spun 
by  the  larvae.  They  rest  on  the  under  side  of  these  nets,  indeed  are  aknost 
enclosed  in  them  as  in  a  cocoon.  This  little  fly  is  a  most  interesting  insect 
because  of  its  ocean-water  habitat — very  few  insects  live  in  salt  water,  and 


1/ 


almost  no  others  have  so  truly  an  ocean  home,  except 
the  curious  salt-water  striders,  Halobates  (see  p. 
197),  which  live  on  the  surface  of  the  ocean  far  out 
at  sea.  It  is  interesting,  too,  because  of  its  structu- 
ral modifications,  the  atrophied  wings,  rudimentary 
balancers,  etc.,  which  set  it  off  widely  from  all 
other  flies.  Its  tide-pool  habitat  is  undoubtedly  the 
result  of  a  slow  migration  and  adaptation  in  the 
course  of  many  generations  on  the  part  of  some 
shore-inhabiting  fly.  There  are  many  small  flies 
which  frequent  ocean  beaches  and  rocks,  feeding  on 


Fig.  426. — Larvae  and  pupas  of  Simidium  sp.  on  edge  of  stream,  May-fly  on  projecting 

twig.     (After  Felt.) 


The  Two-winged  Flies 


313 


decaying  seaweed,  etc.,  and  from  among  these  this  species  has  no  doubt 
gradually  worked  its  way  out  to  the  very  verge  of  the  shore-line,  becoming 
gradually  adapted  in  habit  and  structure  to  the  conditions  of  its  new 
habitat. 

^  Besides  the  mosquitoes  and  punkies  a  third  kind  of  fly  assails  the  rod- 
and-Hne  fisherman,  the  hunter,  and  the  camper  in  forests  and  along  the  streams; 
black,  stout-bodied,  hump-backed,  short-legged,  broad-winged  flies  (Fig. 
424)  from  one-sixth  to  one-fourth  of  an  inch  long,  with  short  but  strong 
piercing  proboscis.  These  are  black-flies,  buffalo-gnats  or  turkey-gnats,  as 
they  are  variously  called,  composing  the  small  family  Simuliidas,  distributed 
all  over  this  country,  but  especially  abundant  in  the  southern  states,  where 
they  attack  cattle  so  fiercely  and  in  such  great  swarms  that  the  animals  are 
driven  frantic  and  sometimes  even  killed  by  a  violent  fever  produced  by  the 
terrible  biting. 

The  larvae  (Fig.  426)  are  odd,  squirming,  slippery,  little  black  "worms," 
which,  clinging  by  the  hind  tip  of  the  body,  occur  in  dense  colonies  or  patches 
on  the  smooth  rock  bed  in  shallow  places 
of  swift  streams.     The  lip  of  a  fall  is  a 

favorite    place    for    them.       The   swift-         f^  }^[fp.  \       \md. 

running  water  constantly  affords  them 
an  abundant  air  and  food  supply.  The 
free  or  head  end  of  the  body  is  provided  j^""  ^"^^  // 


mjrp 


Fig.  427-  Fig.  428. 

Fig.  427.— Mouth-parts  of  female  black-fly,  Simuliiim  sp.  lep.,  labrum;  hyp.,  hypo- 
pharynx;  md.,  mandible;  mx.,  maxilla;  7nxp.,  maxillary  palpus;  li.,  labium;  pg., 
paraglossa.     (Much  enlarged.) 

Fig.  428.— Mouth-parts  of  larva  of  black-fly,  Simulium  sp.  lb.,  labrum;  ep.,  epipharvnx; 
md.,  mandible;  mx.,  maxilla;  mxp.,  maxillary  palpus;  mxl.,  maxillary  lobe;'  li., 
labium;    hyp.,  hypopharynx.     (Much  enlarged.) 


with  a  conspicuous  pair  of  freely  movable  brushes  which  collect  food  from 
the  water.  The  cHnging  to  the  rock  is  effected  by  means  of  silk  spun 
from  the  mouth,  and  by  the  skilful  use  of  silken  threads  the  larva?  can 
move  about  over  the  submerged  rock  bed  without  being  washed  away  by 
the  swift  water.     When  ready  to  pupate,  which  is  after  about  a  month  of 


3 1 4  The  Two-winged  Flies 

larval  life  (under  favorable  conditions  of  temperature  and  food-supply),  the 
larva  spins  a  little  silken  cornucopia-like  cocoon  (Fig.  426)  fastened  to  the 
rock  by  the  httle  end,  and  often  fastened  by  the  sides  to  adjacent  cocoons. 
The  large  free  end  is  left  open.  In  this  cocoon  it  pupates,  and  after  about 
three  weeks  the  winged  fly  issues.  The  eggs  are  laid  in  patches  on  the  rocks 


Fig.  429. — Longitudinal  section  of  head  of  old  larva  of  black-fly,  Simulium  sp.,  showing 
adult  mouth-parts  developing  inside  of  or  corresponding  with  the  larval  mouth- 
parts.  /.OT(/.,  larval  mandible;  /.wix.,  larval  maxilla;  /./?.,  larval  labium;  /.c,  larval 
cuticle;  /.a.,  larval  antenna ;  i.w J.,  adult  mandible;  i.wx.,  adult  maxilla;  i./i.,  adult 
labium;  i.d.,  adult  hypoderm  (cell-layer  of  skin);  i.a.,  adult  antennae;  i.e.,  adult 
eye.     (Much  enlarged.) 


just  below  the  surface  of  the  water,  or  on  the  spray-dashed  sides  of  boulders 
in  the  stream  or  on  its  margin. 

'  In  the  same  places  where  the  Simulium  larvae  live,  that  is,  on  the  smooth 
rock  faces  of  stream  bed  and  lip  of  fall  under  the  thin  apron  of  swift  silver 
water  of  mountain  streams,  live  also  the  curious  flattened  larvae  (Fig.  430)  of 
the  net-winged  midges  or  Blepharoceridae.  This  small  family  of  interesting 
flies,  comprising  only  eighteen  species  in  the  whole  world,  of  which  seven 
belong  to  this  country,  is  one  with  which  the  general  collector  will  hardly 
become  acquainted  unless  he  takes  particular  pains  to  do  so.  But  the  pains 
are  well  worth  while,  for  they  are  not  pains  at  all,  but  pleasures.  In  the  first 
place,  the  larvce — and  they  must  be  looked  for  first,  the  winged  flies  being  very 
rare,  very  retiring,  and  hardly  distinguishable,  until  captured,  from  a  number 
of  other  common  and  less  interesting  kinds — live  only  in  the  most  attractive 
parts  of  the  most  attractive  mountain  brooks.  I  have  found  them  in  a  tiny 
swift  stream  near  Quebec,  in  two  or  three  hillside  brooks  near  Ithaca, 
N.  Y.,  in  roaring  mountain  torrents  in  the  Rocky  Mountains,  and  in  similar 
plunging  streams  in  the  Sierra  Nevada  and  Coast  Range.  Clinging  by  a 
ventral  series  of  six  suckers  to  the  smooth  shining  rock  bed,  the  short  broad 


The  Two-winged  Flies 


315 


larvae  squirm  slowly  around,  feeding  on  diatoms  and  other  microscopic  water 


\    A      /  . 


Fig.  430.  Fig.  431. 

Fig.  430. — Larva  of  net-winged  midge,  Bihiocephala  comstocki.  At  left,  dorsal  view; 
at  right,  ventral  view,  ant.,  antennae;  l.p.,  lateral  processes;  t.g.,  tracheal  gills; 
s.,  sucker.     (Natural  length,  f  to  \  inch.) 

Fig.  431. — Cross-section  of  body  of  larva  of  net-winged  midge,  showing  anatomical 
details  of  sucker  and  other  parts,  h.,  heart;  al.c,  alimentary  canal;  l.p.,  lateral 
process;  v.c,  ventral  nerve-cord;  r.,  rim  of  sucker;  s.,  stopper  of  sucker;  m.s.c, 
muscles  for  retracting  sucker  and  contracting  body;  t.,  tendon  at  end  of  muscles. 
(Much  enlarged.) 


organisms,  and  never  suffering  themselves  to  get  into 
planted  from  the  highly  aerated  swift  water  of  the 
stream's  center  to  the  slow  water  of  eddies  or  pools 
along  the  bank,  they  die  very  soon.  When  ready 
to  pupate  they  gather  in  small  patches,  still  keeping 
in  the  swift  water,  and  each  changes  into  a  curious 
flattened,  turtle-shaped,  motionless,  non-feeding  pupa 
(Fig.  432)  which  is  safely  glued  to  the  rock  face  by 
its  under  surface.  The  dorsal  wall  is  thick  and  black, 
and  projecting  from  it  at  the  broad  front  head  end 
is  a  pair  of  breathing-organs,  each  composed  of  three 
or  four  thin  plate-like  gills.  When  the  fly  is  ready 
to  emerge  the  pupal  skin  splits  longitudinally  along  the 
back,  and  the  delicate  body  pushes  up  through  this 
slit,  and  through  the  shallow  swift  water  until  the 
wings  can  be  outspread.  All  this  is  quickly  done, 
the  fly  being  enchained  by  its  long  legs,  which  cling 
to  the  pupal  shell   until  it    can   fly  away.     But  the 


slow  water.      Trans- 


FiG.  432. — Pupa,  dorsal 
aspect,  of  net-winged 
midge,  Bihiocephala 
comstocki.  Note  re- 
spiratory leaves  on 
dorsum  of  prothorax. 
(Natural  length,  J  inch.) 


3i6 


The  Two-winged  Flies 


Fig.  433.  Fig.  434. 

Fig.  433. — Net-winged  midge,  Bibiocephala  elegantuliis,  female.  (Natural  length  of 
body,  f  inch.) 

Fig.  434. — Mouth-parts  of  female  net-winged  midge,  Bibiocephala  doanei.  l.ep.,  labrum- 
epipharynx;  ind.,  mandible;  mx.,  maxilla;  mxl.,  maxillary  lobe;  mxp.,  maxillary 
palpus;    li.,   labium;    pg.,   paraglossa;    hyp.,  hypopharynx.     (Much  enlarged.) 


Fig.  435. — Heads  of  female  (at  left)  and  of  male  (at  right)  of  net-winged  midge,  Bibio- 
cephala comstocki,  showing  division  of  eyes  into  two  parts,  the  upper  part  with  fewer 
and  larger  facets  than  the  lower  part.     (Much  enlarged.) 


The  Two-winged  Flies 


317 


swift  water  works  great  havoc  among  the  weak,  soft-bodied  emerging  creatures. 
I  have  watched  many  flies  issuing,  and  a  large  proportion  of  them  get  swept 
away  and  presumably  drowned  before  they  can  get  their  wings  unfolded 
and  themselves  clear  of  the  torrent.      It  is  an  extraordinary  life-history  that 


Fig.    436. — Primarv   venation   of   wing   of   net-winged   midge,    Bibiocephala   comstocki. 
R^,  R^,  etc.,  branches  of  the  radial  vein.     (Much  enlarged.) 

these  files  have,  and  the  great  danger  attending  the  transformation  to  the 
adult  stage  probably  partly  explains  why  the  species  are  so  few.  It  is  an 
unsuccessful  type  of  insect  hfe;  the  family  is  probably  becoming  extinguished. 
Because  the  few  living    species  are  so  widely  distributed   over  the  world — 


A 

Fig.  437.  Fig.  438. 

Fig.  437. — Diagram  of  cross-section  of  head  through  compound  eyes  of  net-winged 
midge,  Blepharocera  capitata,  female,  o,  ocelli;  br.,  brain;  o.l.,  optic  lobes;  /./.,  large 
facets;    s.}.,  small  facets. 

Fig.  438. — Mouth-parts  of  larva  of  net-winged  midge,  Bibiocephala  doanei.  md.,  man- 
dible; mx.,  maxilla;  l.ep.,  labrum-epipharynx;  li.,  labium;  hyp.,  hypopharynx. 
(Much  enlarged.) 


theV  occur  in  North  America,  South  America,  and   Europe — entomologists 
believe  that  in  past  ages  the  family  was  much  larger  than  it  now  is. 

The  flies  (Fig.  433)  themselves  can  be  distinguished  when  in  hand  by 
the  curious  secondary  or  pseudo  net-veining  of  the  wings.     These  faint  cross 


3i8 


The  Two-winged  Flies 


and  diagonal  veins  are  the  marks  of  the  creases  made  by  the  compact  folding 
of  the  wings  in  the  pupal  shell.  The  females  are  provided  with  long  saw- 
edged  mandibles  (Fig.  434),  and  are  predatory  in  habit,  catching  smaller 
flying  insects,  especially  Chironomid  midges,  lacerating  their  bodies  with 
the  mandibular  saws  and  sucking  the  blood.  The  males  have  no  mandibles, 
and  probably  take  flower-nectar  for  food.  Both  males  and  females  of  several 
genera  have  the  compound  eyes  divided 
into  a  large-facetted  and  a  small-facetted 
part  (Figs.  435  and  437).  The  egg-laying 
has  not  yet  been  observed,  although  the 
eggs  must  almost  certainly  be  deposited 
on  rocks  in  the  stream  or  on  its  edge. 

With  the  mosquito  wrigglers  and  the 
blood-worms  (larvae  of  the  Chironomidae) 
may  perhaps  be  found  a  third  kind  of  fly 
larva  (Fig.  440),  a  slender,  pale-colored, 
cylindrical  Httle  "worm,"  about  one- 
third  of  an  inch  long,  which  can  be 
distinguished  from  the  other  aquatic 
larvae  by  its  two  pairs  of  short  leg-like 
processes  borne  on  the  under  side  of  the 


Fig.  439.  Fig.  440. 

Fig.  430. — Diagram  of  horizontal  section  through  head  of  old  larva  of  net-winged  midge, 
Bibiocephala  doanei,  showing  formation  of  adult  head-parts  inside,  l.md.,  larval 
mandible;  /.wx.,  larval  maxilla;  /.c,  larval  cuticle;  i.wrd.,  adult  mandible;  i.mx.p., 
adult  maxillary  palpus;  id.,  hypoderm  (cell-layer  of  adult  skin  of  head);  i.e.,  adult 
eye.     (Much  enlarged.) 

Fig.  440. — Larva  of  Dixa  sp.,  with  dorsal  aspect  of  head  in  upper  corner.  (From  life; 
much  enlarged.) 


fourth  and  fifth  body  segments.     It  usually  keeps  the  body  bent  almost  double, 
and  when  feeding  near  the  surface  the  head  is  twisted  so  that  the  under  or 


The  Two-winged  Flies 


319 


mouth  side  faces  up  although  the  rest  of  the  body  has  its  ventral  aspect  facing 
down.  This  larva  belongs  to  one  of  the  midge-Hke  flies  of  the  genus  Dixa 
(Fig.  440),  which  is  the  only  genus  in  the  family  Dixidae,  represented  by  about 
a  dozen  North  American  species.  The  winged  flies  (Fig.  442)  are  found  in 
moist  places,  densely  grown  over  with  bushes  or  rank  herbage,  in  woods. 
Although  resembling  mosquitoes  and 
Chironomid  midges  in  general  appear- 
ance, they  can  be  readily  distinguished 
from  them  by  the  arrangement  of 
the  wing-veins  (Fig.  444). 

An  interesting  small  group  of 
readily  recognizable  flies  is  the 
family  Psychodida%  or  "moth-fly" 
family.  The  vernacular  name  comes 
from  the  slight  resemblance  to  minute 
moths  shown  by  these  flies  because 
of  the  hairy  broad  wings,  which  are 
held  over  the  back  when  the  fly  is  at 
rest  in  the  roof-like  manner  of  the 
moths  (Fig.  445).     The  largest  of  these   Fig.  441. — ^Pupa  of  Dixa  sp. 

flies  are  onlv  about   one-sixth  of  an   -p^^^^f.  ''    n- 

riG.  442. — Dtxa  sp. 

inch  long,  and  are  rarely  distinguished 
except  by  careful  observers.     I  have  found  them  especially  common  in  gar- 
dens  near   the  seashore  in  CaUfornia,  and  also  in  the   overhanging  foliage 


Fig. 


442. 

(Much  en-> 

(Much  enlarged.) 


Fig.  443. — Mouth-parts  of  Dixa  sp.,  female,  l.ep.,  labrum-epipharynx;  tnd.,  mandible; 
OTjf.,  maxilla;  wx./.,  maxillary  lobe;  wjc./).,  maxillary  palpus;  /i.,  labium;  /»^.,  para- 
glossa;    gl.,  glossa;    hyp.,  hypopharynx. 

of  trees  and  shrubs  bordering  the  swift  little  mountain  streams  of  the  Coast 
Range.      In  one  of  these    streams   I   was   fortunate    enough    to   find   the 


320 


The  Two-winged  Flies 


immature  stages  of  one  moth-fly  species,  Pericoma  calijornica,  which  is,  so 
far,  the  only  North  American  member  of  this  family  whose  life-history  is 
known.  The  larvae  (Fig.  446),  which  are  Httle  slug-hke  creatures,  one- 
tenth  of  an  inch  long,  cling  by  a  row  of  eight  suckers  on  their  ventral  side 
to  stones  in    or   on  the    margin  of  the  stream,  where  they  are   constantly 


■n^ 


Fig. 


Fig.  444.  Fig.  445. 

444. — Diagram  of  wing  of  Dixa  sp.,  showing  venation. 


Fig.  445. — A   moth-fly,    Pericoma   calijornica.     (Much   enlarged.) 

wetted  by  the  dashing  water.  When  ready  to  pupate  the  larvae  crawl  a  little 
higher  on  the  stones,  where  only  the  spray  will  reach  them,  and,  fixing  them- 
selves to  the  rock  face  by  a  gummy  exudation,  change  to  small  flattish, 
turtle-backed  pupae  (Fig.  446),  each  with  a  pair  of  club-  or  trumpet-shaped 
respiratory  horns  on  the  back  of  the  prothorax.  They  look  indeed  much 
like  dwarf  net-winged  midge  pupae.     After  ^     ^-i^i  lmuPS^ 

about  three  weeks  the  adults  issue  and  fly 

mxp. 


tax. 


Fig.  446.  Fig.  447. 

Fig.  446. — Larva,  ventral  surface  (at  left),  and  pupa,  dorsal  surface  (at  right),  of  the 
moth-fly,  Pericoma  calijornica;  also  enlarged  prothoracic  respiratory  tube  of  pupa. 
(Much  enlarged.) 

Fig.  447. — Mouth-parts  of  moth-fly,  Psychoda  sp.  Ih.,  labrum;  inx.,  maxilla;  inx.p., 
maxillary  palpus;  mx.l.,  maxillary  lobe;  li.,  labium;  pg.,  paraglossa;  hyp.,  hypo- 
pharynx. 

up    into   the   overhanging   foliage,  where    they   spend   most    of    their    time 
resting  on  the  under  side  of  the  leaves. 

The  largest  family  of  nematocerous  flies  in  point  of  number  of  species, 


The  Two-winged  Flies  321 

and  that  one  containing  the  largest  flies  in  the  whole  order,  is  the  family 
Tipulida;,  whose  long-legged,  narrow-winged  members  are  famiharly  known  as 
crane-flies,  leather-jackets,  and  "  granddaddy-long-legs. "  The  granddaddy- 
long-leg  flies,  which  have  wings,  should  not  be  confused  with  the  often  simi- 
larly named  harvestmen,  which  are  alhes  of  the  spiders,  have  no  wings,  and 
have  four  instead  of  three  pairs  of  legs.  The  Tipulid  legs  are '  extremely 
fragile,  breaking  off  at  a  touch.  Most  slender-bodied,  long-  and  thin-legged; 
two-winged  insects  of  more  than  one-half-inch  length  of  body  are  Tipulids. 
There  are  some  smaller  species, 
however,  which  might  be  mis- 
taken for  midges  or  mos- 
quitoes, were  it  not  that  all 
Tipuhds  bear  a  distinct  V- 
shaped   mark    (suture)    on   the    Fig.  448.— Diagram  of  wing   of  crane-fly,  Sim- 

;       .    ,        ,  -  ^  ,  plecta  sp.,  showing  venation, 

back  of  the  thorax.     More  than 

three  hundred  species  of  this  family  are  known  in  the  United  States,  and  they 
are  common  all  over  the  country,  in  meadows,  pastures,  along  roadsides, 
stream-banks,  and  in  viroods.  The  flight  is  uneven,  slow,  and  weak,  and 
the  ungainly  fhes  with  their  long  middle  and  hind  legs  training  out  behind, 
and  the  front  legs  held  angularly  projecting  in  front,  are  unmistakable 
when  seen  in  the  air. 

The  eggs  are  laid  in  the  ground  at  the  bases  of  grasses  and  pasture  plants, 
or,  by  some  species,  in  mud  or  slime.  The  footless,  worm-like,  dirty-white 
larvae  feed  on  decaying  vegetable  matter,  fungi,  or  on  the  roots  or  leaves  of 
green  plants.     The  root-feeders  do  some  damage  to  meadows  and  pastures. 

The  largest  Tipulid,  and  the  largest  species  in  the  whole  order  of  flies,  is 
the  giant  crane-fly,  Holorusia  ruhiginosa  (Fig.  449),  common  in  CaHfornia. 
Its  body  is  nearly  two  inches  long,  and  its  legs  are  from  two  to  two  and  one- 
half  inches  long,  so  that  the  spread  of  legs  is  four  inches.  The  eggs  are 
laid  in  the  ooze  of  wet  banks  of  little  streams  where  faUen  leaves  are  decay- 
ing and  subdrainage  water  is  always  slowly  trickling  out  from  the  soil.  The 
larvae  (Fig.  450)  lie  in  this  slimy  bed,  in  crevices  or  on  narrow  ledges  of  rock, 
with  the  posterior  tip  of  the  body  bearing  the  two  breathing-openings  (spi- 
racles) held  at  the  surface.  The  soft  ooze,  composed  of  soil  and  slowly 
decomposing  leaves,  is  swaUowed,  and,  as  it  passes  through  the  ahmentary 
canal,  the  organic  material  digested  out  of  it.  The  footless,  worm-like 
larvae  grow  to  be  two  and  one-half  inches  long,  but  can  contract  to  less  than 
an  inch.  The  duration  of  the  larval  life  is  not  yet  known,  but  it  is  at  least 
several  months.  The  pupae  (Fig.  450),  which  are  provided  with  a  pair  of 
long,  slender  respiratory  horns  on  the  prothorax,  lie  motionless  in  the  slime 
for  twelve  days,  when  the  great  flies  emerge  and  fly  up  into  the  foHage  of 
the   stream  bank. 


322 


The  Two-winged  Flies 


Next  to  the  mosquitoes,  the  worst  pests  among  the  nematocerous  flies  are 
various  species  of  the  gall-midge  family,  Cecidomyidae,  a  family  in  which 
all  the  stages,  larval,  pupal,  and  adult,  of  all  the  species  are  terrestrial.     The 

gall-midges  are  the  frailest, 
smallest,  and  least  conspicuous 
of  all  the  flies,  but  their  great 
numbers  and   vegetable   feeding 


Fig.  449.  Fig.  450, 

Fig.  449. — The  giant  crane-fly,  Holorusia  rubiginosa,  male.      (Three-fourths  natural 

size.) 
Fig.  450. — Larva  (at  left)  and  pupa  (at  right)  of  giant  crane-fly,  Holorusia  rubiginosa; 

in  middle   of   figure   enlarged   posterior  aspect   of  larval   body,  showing   spiracles. 

(Larva  and  pupa  three-fourths  natural  size.) 


and  gall-making  habits  make  them  formidable  enemies  of  many  of  our 
cultivated  plants.  The  tremendous  aggregate  losses  suffered  by  the  wheat- 
growers  of  this  country  from  the  ravages  of  the  Hessian  fly,  the  damage 
to  clover-fields  by  the  clover-leaf  and  clover-seed  midges,  and  the  injuring 
,  or  killing  of  thousands  of  pine-trees  from  the  attacks  of  the  minute 
pine  Diplosids,  are  evidences  of  the  great  economic  importance  of  the 
delicate  little  gall-gnats.  About  one  hundred  species  are  known  in  this 
country,  and  of  these  most  are  more  or  less  destructive  to  cultivated  herbs, 
shrubs,  or  trees. 

The  tiny  bodies  of  the  flies  are  usually  covered  with  fine  hair,  easily 
rubbed  off,  and  the  antennae  bear  whorls  of  larger  hairs,  which,  with  some 
species,  are  attached  by  both  ends,  thus  making  little  hair  loops.  The 
minute  eggs,  reddish  or  white,  are  usually  deposited  in  or  on  growing  plant- 
tissue,  and  the  little  footless,  headless,  maggot-like  larvae  probably  derive 
most  of  their  food  by  imbibing  it  through  the  skin.     Lying  with  the  body 


The  Two-winged  Flies  323 

practically  immersed  in  plant-sap,  the  thin  body-wall  acts  as  an  osmotic 
membrane  through  which  an  interchange  of  fluids  takes  place  automati- 
cally. The  Cecid  larva  has  to  eat  whether  it  will  or  not,  and  has  to  eat 
practically  all  of  the  time!  These  larvai  may  be  distinguished  by  their 
possession  of  a  strange  little  cliitin  plate  on  the  under  side  of  the  front  part 
of  the  body,  called  the  breast-bone.  What  the  exact  use  of  this  little  sclerite 
is  has  not  yet  been  determined.  Perhaps  it  helps  in  locomotion,  perhaps 
in  rasping  or  lacerating  the  soft  plant-tissue  to  increase  the  flow  of  sap.  The 
larvae  pupate  where  they  lie,  sometimes  spinning  a  thin  silken  cocoon,  some- 
times transforming  within  the  hardened  last  larval  moult,  sometimes  with 
no  special  protecting  covering  at  all. 

The  most  notorious  gall-gnat  is  the  wheat-pest,  known  as  the  Hessian 
fly,  Cecidomyia  destructor,  and  distributed  over  all  the  United  States  east  of 
meridian  100°,  as  well  as  in  California.  By  the  ravages  of  its  larvae,  feeding 
as  they  do  on  the  sap  of  growing  wheat,  this  minute  fly  causes  an  annual  loss 
in  this  country  of  approximately  ten  million  dollars.  This  enormous  direct 
tax  is  paid  by  those  farmers  who  prefer  to  farm  in  the  good  old  way,  with  a 
strong  belief  in  the  dispensations  of  an  erratic  Providence,  rather  than  to 
do  their  farming  as  modified  by  modern  knowledge  and  practice.  The 
tax-collecting  insect,  which  is  a  tiny  delicate  blackish  midge  about  one- 
tenth  of  an  inch  long,  lays  its  eggs  in  the  creases  or  furrows  of  the  upper 
surface  of  the  leaves  of  young  wheat,  and  the  hatching  larva;  wriggle  down 
to  the  sheathing  bases  of  the  leaves,  where  they  lie  and  drain  away  the  sap 
of  the  growing  plant.  When  full-grown  they  pupate  within  the  outer  hardened 
brown  last  larval  cuticle,  and  resemble  very  much  a,  small  spindle-shaped 
seed.  This  is  called  commonly  the  "flaxseed"  stage.  The  adult  soon 
issues  and  after  a  few  days  of  flight  and  egg-laying  dies.  There  may  be  as 
many  as  four  or  five  generations  in  a  year,  both  spring  and  winter  wheat 
being  attacked.  The  remedies  are  the  late  planting  of  winter  wheat,  the 
burning  or  plowing  in  of  the  stubble  after  harvesting,  and  the  early  planting 
of  strips  of  decoy  wheat  about  the  field,  which  shall  attract  the  egg-laying 
females  and  may  be  afterwards  plowed  under  with  the  myriad  eggs  it  contains. 
The  Hessian  fly  is  a  European  insect  brought  unintentionally  to  this  country 
about  1778,  but  probably  not,  as  often  said,  with  the  straw  brought  by  the 
Hessian  troopers  of  the  Revolutionary  War.  It  attacks  rye  and  barley  as 
well  as  wheat,  and  has,  in  turn,  to  withstand  the  combined  attacks  of  half 
a  dozen  hymenopterous  parasites,  which  are  said  to  destroy  nine-tenths 
of  all  the  Hessian-fly  larvae.  Without  these  natural  checks  to  its  increase 
this  pest  would  destroy  every  wheat-field  in  this  country  in  a  very  few 
years. 

In  1896  the  Monterey  pines,  Pinus  radiata,  much  grown,  together 
with  the  famous  Monterey  cypresses,  as  ornamental  trees  on  the  San  Fran- 


324 


The  Two-winged  Flies 


Cisco  peninsula,  showed  a  peculiar  stunting  and  gall-like  swelling  of  the 
leaves.  Since  then  this  deformation  has  appeared  so  abundantly  and  widely 
within  the  range  of  this  tree  that  the  species  is  actually  threatened  with 
extinction,  the  shortened,  swollen  needles  not  being  able  to  perform  the 
essential  food-assimilating  functions  of  green  leaves.  This  injury  is  due 
to  a  single  species  of  Cecid  fly  known  as  Diplosis  pini-radiata  (Fig.  451), 


Fig.  451. — The  Monterey-pine  midge,   Diplosis  pini-radiata;    eggs  in  upper  left-hand 
corner;   pupa,  larva,  breast-bone  of  larva,  and  adult  female.     (Much  enlarged.) 

which  lays  its  eggs  at  the  base  of  the  growing  new  needles  and  whose  larvae 
hatching  and  lying  here  use  up  the  sap  necessary  for  the  development  of 
the  needles.  Hundreds  of  Monterey  pines  have  been  cut  down,  and  unless 
the  natural  enemies  of  this  little  fly,  of  which  two  or  three  have  been  dis- 
covered, get  the  upper  hand  of  the  pest,  this  splendid  species  of  pine  may 
be  wholly  destroyed.  A  half-dozen  other  species  of  Diplosis  are  known 
in  this  country  and  Europe  as  pests  of  conifers,  but  no  other  pine  species 
seems  to  have  suffered  quite  so  severely  as  this  interesting  Cahfornian  one, 
whose  whole  geographical  range  extends  over  but  a  thousand  square  miles, 
and  which  is  thus  specially  liable  to  destruction  by  concentrated  insect 
attack. 

If  the  collector  will  break  up  and  examine  carefully  almost  any  old  or 
partially  decaying  toadstools  or  shelf  fungi  from  trees,  he  will  find  in  the 
soft  fungous  body  numerous  small  translucent  white  maggot-like  larvae,  the 
larvae  of  fungus  gnats  or  members  of  the  family  Mycetophilidae.  The  gnats 
themselves  are  slender  delicate  flies,  mostly  with  clear  wings,  though  some 
common  species  have  dark  wings,  with  the  basal  segment  (coxa)  of  the  legs 
unusually  long  and  the  antennae  in  most  cases  free  from  the  whorls  of  long 
hairs  so  characteristic  of  the  Chironomidae,  Culicidae,  and  other  families  of 
flies  otherwise  much  resembling  the  fungus-gnats.  The  flies  are  to  be  looked 
for  on  decaying  vegetable  matter,  especially  fungi,  and  in  damp  places. 

The  eggs  are  laid  variously:  on  fungi,  in  decaying  wood,  among  decom- 
posing leaves,  in  animal  excrement,  and  under  the  bark  of  trees.     The  larvae 


The  Two-winged  Flies 


325 


feed  on  the  decomposing  substance  in  which  the  eggs  are  ^aid,  sometimes 
spinning  silken  webs  for  protection.  They  pupate  in  the  food-substance  or 
crawl  away  to  some  more  sheltered  spot,  often  forming  a  thick  cocoon  in 


Fig.  452. — A  fungus-gnat  of  the  family  Mycetophilida;    larva,   pupa,   and  adult. 

(Much  enlarged.) 

which  to  transform.  Perhaps  the  most  singular  habits  noted  in  the  family 
are  those  connected  with  the  strong  gregarious  instinct  which  leads  the 
larv£e  of  many  species  to  hve  closely  together.  Some  of  the  species  of  Sciara, 
known  as  "army-worms,"  have  "the  singular  propensity  of  sticking  to- 
gether in  dense  patches,  and  will 
form  processions  sometimes  twelve 
or  fourteen  feet  in  length  and  two 
or  three  inches  broad.  This  phe- 
nomenon has  been  observed  fre- 
quently both  in  Europe  and  Amer- 
ica, but  the  reason  therefor  is  not 
yet  well  understood,  though  the 
object  of  the  migration  seems  to  be 
the  search  for  better  feeding-grounds."  Various  species  of  this  genus  live 
in  potatoes  and  other  vegetables,  while  the  serious  injury  to  potatoes  called 
"scab"  is  caused  by  a  fungus-gnat  known  as  Epidapus  scabies. 

With  larger  and  more  robust  bodies  and  relatively  shorter  and  thicker  an- 
tenncT,  the  March-flies,  Bibionida?,  serve  as  a  sort  of  transition  family  between 
the  long-legged,  slender -bodied  midge  type  of  fly  with  its  thread-like  hairy 
antennae,  and  the  compact,  heavy-bodied,  short-legged  type  of  fly  with  short 
and  club-Hke  three-segmented  antennae,  characteristic  of  the  many  families 
grouped  in  the  section  Brachycera.  The  March-flies  (Fig.  454)  are  from 
one-eighth  to  one-half  inch  long,  with  fairly  robust,  often  hairy,  body,  black- 


FiG.  453. — Diagram   of  wing  of  fungus-gnat, 
Mycetophila  sp.,   showing  venation. 


326 


The  Two-winged  Flies 


ish  or  blacK  and  red,  strong  legs,  large  clear  or  smoky  wings,  and  stout  an- 
tennae about  as  long  as  head  and  thorax  together  and  composed  of  nine  to 
twelve  segments.  They  may  be  seen  often  in  large  numbers  flying  heavily 
over  gardens  and  fields  or  in  woods,  early  in  the  spring.  The  eggs  are  laid 
in  the  soil  or  in  decaying  vegetation  or  in  sewers  and  excrement,  the  larvae 
feeding  usually  on  decom.posing  substances.  With  some  species,  however, 
the  larvas  feed  on  the  roots  of  grains  or  grasses  and  in  this  way  may  do  serious 
damage.  Bibio  tristis,  discovered  in  Kansas  in  1891,  appeared  in  great 
numbers  in  wheat-fields  and  frightened  many  wheat-growers.  As  a  matter 
of  fact,  Httle  injury  seemed  to  be  done.  B.  jemorata,  a  common  species, 
is  deep  red  with  black  wings;  B.  albipennis,  another  abundant  and  wide- 
spread one,  is  black-bodied  with  white  wings.  A  common  CaHfornian  species 
appears  from  the  ground  in  damp  woods  in  great  numbers  in  March.  I 
have  watched  these  flies  issuing  in  countless  numbers 
from  the  soft  rich  forest  floor  in  the  extensive 
Monterey    pine    woods    near    the    Bay    of    Monterey 


Fig.  454.  Fig.  455. 

Fig.  454. — March-fly,    Bibio  albipennis.      (Three  times  natural  size.) 
Fig.  455. — Diagram  of  wing  of  Bibio  albipennis,  showing  venation. 

The  air  danced  with  them,  and  the  pine-trees  and  shrubs  bore  countless 
myriads  on  their  branches.  Professor  Needham  records  a  similar  sight 
in  which  individuals  of  B.  jraternus  formed  the  hosts,  and  a  woodland  pasture 
near  Lake  Michigan  was  the  scene  of  their  appearance.  "I  have  rarely 
come  upon  a  scene  of  greater  animation  than  a  sheltered  hollow  in  this  wood 
presented,"  writes  Professor  Needham.  "There  was  the  undulating  field 
clad  in  waving  grass  and  set  about  with  the  pale-hued  foliage  of  the  white 
oaks;  there  were  the  flowering  hawthorns;  and  there  were  the  myriads 
of  Bibios  floating  in  the  sunshine,  streaming  here  and  there  like  chaff  before 
sudden  gusts  and  swirls  of  air.  All  the  spiders'  webs  in  the  bushes  were 
filled  with  captives;  Httle  groups  of  ants  were  dragging  single  flies  away  to 
their  nests,  and  once  I  saw  overhead  a  chestnut-sided  warbler,  perched  on 
a  bare  bough  directly  in  a  stream  of  passing  flies,  rapidly  pecking  to  right 
and  to  left,  persistently  stuffing  his  already  rotund  maw.  I  counted  a  number 
of  flies  I  could  see  resting  on  the  grass  in  several  small  areas  wide  apart,  and 


The  Two-winged  Flies  .327 

found  the  counts  averaged  fifteen  Bibios  per  square  foot;    and  there  were 

here  in  one  place  forty  acres  of  such  Bibio  territory." 

Two  famihes  of  nematocerous  flies  are  not  included  in  the  key,  and  have 

not  heretofore  been  referred  to.     They  are  the  Orphnephihdae,  of  which  but 

a  single  species  is  known  in  this  country,  viz.,  Orphnephila  testacea,  a  small 

reddish-yellow  fly  without  hairs  or  bristles  on  its  body,  and  with  short  antennae 

apparently  composed  of  two  segments,  but  really  of  ten,  the  apparent  first 

segment   being   made   up   of    three    closely 

opposed  segments,  and  the  second  of  seven. 

The  fly  itself  is  found  along  stream  banks, 

but  nothing  is  known  of  its  immature  stages. 

The  other  family,  Rhvphidae,  or  false  crane-    ^ 

....  .       1      ^  1*10.    456. — Diagram    of    wing 

flies,  is  represented  in  this  country  by  two  Rhyphus  sp. 

genera  containing  several  species.     The  flies 

are  small  and  slender,  with  broad  spotted  wings  veined  in  a  character- 
istic way  (Fig.  456).  The  larvas  of  Rhyphus  are  worm -like,  legless,  naked, 
more  or  less  transparent,  with  snake-like  movements.  They  live  in  water, 
brooks,  pools,  or  puddles,  or  in  rotting  wood,  hollow  trees,  or  manure. 


SECTION    BRACHYCERA, 

The  Brachycera,  or  flies  with  "short  horns,"  i.e.,  short  thick  antennae 
composed  of  few  segments,  in  contrast  with  the  many-segmented  antennae, 
usually  slender  and  long,  of  the  Nematocera,  are  separable  into  three  groups 
of  famihes,  as  indicated  in  the  key  on  page  303,  based  on  a  further  analysis 
of  the  structural  character  of  the  antennae.  These  groups  are,  first,  one  includ- 
ing flies  in  which  the  antennae  are  composed  of  more  than  five  segments  but 
with  all  those  beyond  the  second  coalesced  to  form  a  single  compound 
segment,  bearing  more  or  less  distinct  annulations  indicating  the  component 
subsegments;  second,  one  including  flies  having  antennae  made  of  four  or 
five  distinct  segments;  and  third,  and  by  far  the  largest,  one  including  flies 
with  but  three  segments  in  the  antennae. 

In  the  first  group  are  two  families  and  part  of  a  third;  this  division  of  a 
family  indicating  plainly  the  artificial  character  of  the  subdivision  into 
groups,  the  subdivision  being  merely  convenient.  The  three  famihes  may  be 
distinguished  as  follows: 

The  branches  of  the  radial  vein  (see  Fig.  460)  crowded  together  near  the  costal  (front) 

margin  of  the  wing (Soldier-flies.)     Stratiomyid.*;. 

Venation  normal. 

Alulets,  i.e.,  little  whitish  wing-like  membranous  flaps  at  the  base  of  the  true  wings, 

large (Horse-flies.)       Tabanid^. 

Alulets  small (Snipe-flies.)     Leptid^  (in  part). 


328 


The  Two-winged  Flies 


The  most  familiar  and  interesting  flies  in  this  group  are  the  well-known 
horse-flies,  gad-flies,  or  deer-flies,  Tabanidas.  They  are  all  fairly  large, 
some  indeed  being  among  the  largest  of  our  flies. 

The  great,  black,  swift  horse-flies  that  in  summer  dart  suddenly  at  our 
carriage-horses  and  with  quick  shifting  flight  seem  to  be  fairly  carried 
along  in  the  air  close  to  the  horses,  are  the  most  familiar  representatives  of 


Fig.    457. — Greenhead,    or   horse-fly,    Tabanus   lineola. 

indicated  by  line.) 


(After    Lugger;     natural    size 


the  order.  Many  of  the  smaller  horse-flies  show  gleaming  metalHc  colors, 
especially  about  the  head.  Much  of  this  color  is  in  the  large  compound 
eyes,  and  almost  any  horse-fly  caught  alive  or  just  killed  will  astonish  the 
collector  by  the  brilliant  bands  and  flecks  of  iridescent  green,  violet,  purple. 


Fig.  458. — Diagram  of  wing  ot  Chrysops  sp.,  a  horse-fly,  showing  venation. 

and  copper  on  the  eyes.  The  biting  and  blood-sucking  are  done  by  the 
females  alone,  the  males  lacking  the  sharp  dagger-like  piercing  mandibles 
and  contenting  themselves  with  lapping  up  flower-nectar. 

The  brown  elongate  eggs  of  horse-flies  are  laid  either  on  stems  or  leaves 
of  terrestrial  plants,  or  on  aquatic  plants  or  submerged  stones.  The  larvae, 
whitish,  cylindrical,  tapering  at  both  ends,  and  with  a  series  of  slightly  raised 
roughened  ridges  running  around  the  body,  either  live  in  water,  in  slimy 
places  along  pond  and  brook  shores,  or  in  soft  rich  soil,  and  are  predaceous, 


The  Two-winged  Flies 


329 


feeding  on  small  aquatic  or  underground  creatures,  especially  insect    larva 
and  snails  or  slugs. 

Nearly  200  species  of  horse-flies  are  known  in  North  America.  The 
large  bluish-black  and  brownish-black  ones,  an  inch  long  and  with  dusty 
wings  expanding  for  two  inches  or  more,  belong  to  the  genera  Tabanus  and 
Therioplectes;   the  smaller  "greenheads"  with  banded  wings  and  briUiantly 


^'''■«J^/~^°'^n^"P''ri°^  ^  horse-fly,  Therioplectes  sp.  md.,  mandible;  mx.,  maxilla; 
mx.l.,  maxillary  \ohy  mx.p.,  maxillary  palpus;  hyp.,  hypopharynx;  lb.,  labrum 
ep.,   epipharynx;    h.,   labium;    la.,   labellum.  ^        -'i'  1        ^      >        . 

colored  eyes  and  black  or  brown  and  yellow  bodies  mostly  belong  to  the 
genus  Chrysops.  Silvius  pollinosiis  is  a  beautiful  small  species  with  a  milk- 
white  bloom  over  its  body,  and  with  clear  whitish  wings  with  a  few  small 
brown  spots. 

The  soldier-flies,  Stratiomyidae,  are  unfamiliar  insects,  although  as  many 
species  of  them  as  of  horse-flies  occur  in  this  country.  Many  of  the  species 
have  bright  yellow  or  green  markings,  and  most  of  them  have  the  abdomen 
curiously  broad  and  flattened. 
They  are  found  about  flowers, 
and  can  readily  be  classified, 
after  capture,  by  the  unusual 
character  of  the  venation  (see 
Fig.  460).  The  eggs  are  laid 
on  the  ground  or  on  ^leaves  in  or 
near  water,  some  of  the  larvc-e 
being  terrestrial,  while  others  are 
aquatic.  The  food  seems  to  be  mostly  vegetable,  although  the  larva  of  some 
species  are  believed  to  be  carnivorous.  One  or  two  species  live  in  salt  or 
brackish  water,  and  Sharp  records  that  some  Stratiomyid  larva  were  found 
in  a  hot  spring  in  Wyoming  with  the  water  temperature  only  20°  to  30°  F. 
below  boihng.     They  pupate  within  the  last  larval  skin,  which  is  long  and 


Fig.  460.  —  Diagram    of    wing    of  Odontomyia 
sp.,  showing  venation. 


33°  The  Two-winged  Flies 

tapering  at  one  end.     Some  species  inhabit  ants'  nests,  and  one  is  suspected 
of  living  parasitically  in  bee-hives. 

Stratiomyia  is  a  genus  containing  rather  large  conspicuous  yellow-banded 
flies  with  broad  flattened  abdomen,  while  Sargus,  a  genus  whose  species 
are  common,  has  a  subcyhndrical  abdomen  with  the  whole  body  metallic 
green. 

The  snipe-flies,  Leptidae,  are  a  small  family  represented  by  about  fifty 
North  American  species,  including  flies  having  no  habits  or  structural  pecu- 
liarities appealing  specially  to  popular  interest.  They  are  rather  slender 
and  plainly  colored,  and  rather  heavy  and  slow  in  movement.     They  are 

apparently  all  predatory  in  both  larval 

and  adult  stages.     The  adults  may  be 

best  found,  according  to  Comstock,  in 

low  bushes  and  grass.     The  larvae  Hve 

in  the  ground,  in  moss,  or  in  decaying 

wood,    sometimes   penetrating   to    the 

Fig.  461.— Diagram  of  wing  oi  Chryso-     burrows  of  wood-boring  insects.     The 

phila      thoracica     (LeptiQEe),     showing  .  k   ^      •       ^ 

venation.  species   of   the   genus  Atherix  deposit 

their  eggs  "in  dense  masses  attached 
to  dry  branches  overhanging  water.  Not  only  do  numerous  females  con- 
tribute to  the  formation  of  these  masses,  but  they  lemain  there  themselves 
and  die.     The  larvae  on  hatching  escape  into  the  water." 

In  the  second  group  of  Brachycera,  including  flies  which  have  their  anten- 
nae composed  of  four  or  five  distinct  segments,  there  are  two  famihes,  the 
Asilidae,  or  robber-flies,  and  the  Midaidae,  or  Midas-flies.  These  latter  resemble 
the  robber-flies  in  size  and  general  appearance,  but  differ  from  them  by  having 
the  antennae  rather  long  and  clubbed  at  the  tip.  They  are  predaceous, 
catching  and  devouring  other  flying  insects,  and  the  larvae  of  the  few  species 
whose  life-history  is  known  are  also  carnivorous,  and  seem  to  have  a  special 
fancy  for  the  larvae  of  the  great  wood-boring  grubs  of  the  giant  Prionus 
beetles.  Howard  believes  that  the  large  species,  Mydas  luleipennis,  found 
in  the  Southwest,  mimics  in  coloration  and  general  appearance  for  protection 
or  aggression  the  tarantula-killer  wasp  found  commonly  in  this  country. 

The  Asilidae,  or  robber-flies,  compose  a  considerable  family — nearly  1000 
species  occur  in  this  country — of  large,  swift,  hairy,  ferocious-looking  flies 
which  hve  wholly  by  predatory  attacks  on  other  insects.  The  body  is  usually 
long  and  slender,  tapering  behind  (Fig.  462),  although  in  a  few  genera  the 
abdomen  is  flattened  and  not  unusually  elongate.  The  proboscis  is  strong 
and  sharp,  the  eyes  large  and  keen,  and  the  wings  long  and  narrow  and 
capable  of  carrying  this  insect  hawk  swiftly  and  strongly  in  pursuit  of  its 
prey.  Some  of  the  robber-flies  are  very  large,  an  inch  and  a  half  or  even 
two  inches  long,  and  they  do  not  hesitate  to  attack  other  large  and  strong  and 


The  Two-winged  Flies 


331 


well-defended    insects,   as   bumble-bees,    dragon-flies,    and    the   fierce    and 
active  tiger-beetles.     The  robber-flies  usually  rest  on  the  ground  or  on  low 


Fig.  462.  Fig.  463. 

Fig.  462. — A  robber-fly,   Stenopogon  inquinatus.     (Natural  size.) 
Fig.  463. — A  bumble-bee-like  robber-fly,   Dasyliis    soceata.     (Natural  size.) 

foliage,  and  fly  quickly  up  with  a  buzzing  sound  when  disturbed  or  attracted 
by  prey.  All  the  prey  is  caught  on  the  wing,  held  in  the  long  spiny  feet  of 
the  robber-fly,  and  torn  and  sucked  dry  by  the  sharp  piercing-beak. 


Fig.   464. — ^Diagram  of  wing  of  robber-fly,   Erax  cinerascens,  showing  venation. 

The  larvae  live  chiefly  in  decaying  wood  or  in  soil  containing  decom- 
posing vegetable  matter,  and  are  also  predatory,  feeding  on  grubs  and  other 


Fig.  465. — Mouth-parts  of  robber-fly,  Erax  cinerascens.   li.,  labium;  hyp.,  hypopharynx; 
lb.,  labrum;    mx.,  maxilla;    mxL,  maxillary  lobe;    mxp.,  maxillary  palpus. 

underground  or  wood-boring  insects.  The  pupje  are  curiously  spiny,  the 
spines  being  used  as  a  sort  of  pushing  or  pulling  organ  when  they  get  ready 
to  come  to  the  surface  of  the  ground  or  dead  tree  to  change  into  imagines 

Some  of  the  species  of  the  genera  Laphria  and  Dasyliis  (Fig.  463)  look 
astonishingly    like  bumble-bees  and  wasps,  probably  a  case   of   protective 


332  The  Two-winged  Flies 

mimicry  (see  Chap.  XVII).     Erax  is  a  gemis  with  many  common  gray  and 
black  species  about  an  inch  long,  with  sharp-pointed  tip  of  the  abdomen. 

The  third  section  or  group  of  Brachycerous  famihes  includes  many 
families,  in  all  of  which  the  antennae  have  the  first  two  segments  small  and 
the  third  curiously  large  and  club-like,  and  usually  bearing  a  single  con- 
spicuous bristle-like  hair.  The  families  of  this  group  can  be  distinguished 
by  the  following  table: 

A.      Antennae  composed  of  three  segments,  the  third  usually  large  and  either  with  or 
without  a  bristle  or  style. 
B.      Empodium  pulvilliform,  i.e.,   feet  with  three  little  pads  instead  of  two. 

(Snipe-flies.)     LEPXiDiE  (in  part). 
BB.  Empodium  not  pulvilliform,  i.e.,  feet  with  two  little  pads  and  a  median  bristle 
or  nothing. 
C.      Radial  vein  four-branched. 

D.      Second  branch  of  cubital  vein  extending  free  to  the  margin  of  the 
wing  or  coalesced  with  the   first  anal  vein   for   a   short   distance 

(see  Fig.  466) (Bee-flies.)     Bombyliid^. 

DD.    Second   branch   of   cubital    vein    joining    first   anal    far   from   the 
margin  of  the  wing  (see  lig.  471). 

(Dance-flies.)     Empidid^  (in  part). 
CC.  Radial  vein  with  not  more  than  three  branches. 

D.       Head  with  a  curving  suture  immediately  above  the  antennas. 

(House-flies  and  allies.)     MusciD^. 
DD.  Head  without  such  suture. 

E.      Radial  vein  with  a  knot-shaped  swelling  at  the  point  where 
it  forks,  with  a  small  cross-vein  running  back  iust  at  or  near 
this sweUing  (Fig.  474).  .(Long-legged  flies.)    Dolichopodid^. 
EE.  Wings  without  such  characteristics. 

F.  Second  branch  of  cubital  vem  appearing  as  a  cross- 
vein  or  curved  back  towards  the  base  of  the  wings 
(Fig.  479). 

G.  Proboscis  rudimentary;  mouth-opening  small;  palpi 
wanting;    antennae    with    dorsal    arista. 

(Bot-flies.)     CEsTRiD^. 
GG.  Proboscis  not  rudimentary;    palpi  present;    antennae 
with   terminal   style   or  arista  or  dorsal   arista. 

Empidid^  (in  part). 
FF.  Second    branch    of    cubital    vein    not    appearing    like    a 
cross-vein. 
G.       Front    with    grooves    or   a    depression    beneath    the 

antennae (Wasp-flies.)      CoNOPiDiE. 

GG.  Front  convex  beneath  the  antennae;  a  spurious 
vein  usually  present  between  radius  and  media 
(Fig.  479) (Flower-flies.)     SyRPHiD.E. 

The  famihes  of  flies  named  in  the  above  key  contain  many  hundreds  of 
species  but  few  of  which  are  at  all  popularly  known.  The  bot-flies  (CEstridae), 
house-flies,  flesh-flies,  bluebottles  and  stable-flies  (Muscidas  calyptrata),  and 


The  Two-winged  Flies  333 

the  cheese-skippers  and  pomace-flies  (Muscidae  acalyptratae)  are  about  the 
only  names  in  the  Hst  of  these  hundreds  which  seem  at  all  familiar.  The 
flower-flies  (Syrphida?)  and  bee-flies  (BombyHidaj)  are  numerous,  often 
seen,  and,  what  is  more,  often  definitely  noted  and  admired,  but  "beautiful 
flies"  is  about  as  specific  a  name  as  they  ever  get.  The  bristly  parasitic 
Tachinid  flies  are  noticed  now  and  then  by  the  nature  student,  and  the 
dancing  Empidids  interest,  in  a  decided  but  irritating  way,  drivers  and 
bicyclers  in  the  dance-fly  mating-time.  But  even  entomologists,  professional 
as  well  as  amateur,  unless  they  are  special  collectors  and  students  of 
Diptera,  recognize  but  few  of  the  hosts  of  small  flies  that  fill  the  air  during 
the  long  summer  days. 

In  the  above  key  only  the  larger  and  more  commonly  represented  famihes 
are  included,  so  that  it  will  be  possible  for  a  collector  using  this  book  to 
find  himself  possessed  of  a  fly  which  will  prove  intractable  when  an  attempt 
is  made  to  classify  it  into  its  proper  family.  But  such  unfortunate  happen- 
ings will  be  very  infrequent,  as  only  small  families  of  obscure  or  rare  species 
are  thus  omitted. 

Poised  almost  motionless  in  the  air  a  few  inches  above  a  sunny  path  or 

roadway,  or  darting  away,   when   disturbed,  with  lightning  swiftness  and 

having  all  the  seeming  of  bees,  hairy,  plump-bodied,  and  amber-colored,  certain 

bee-flies  (Bombyhidas)  are  rather  familiar  acquaintances  of  the  summer  field 

student.     Other  bee-flies,  as  swift 

and  as  beautiful,  are  less  bee-like 

because  of  the  striking  "pictures" 

in   the  wings,  blackish  or   brown 

blotches  conspicuous  in  the  thin, 

otherwise    clear    wing-membrane. 

Some  of   these    bee-flies  have '  an 

1,       ,  ,      J  ,         .     Fig.  466. — Diagram    of  wing   of   Anthrax  ful- 

unusually   long   slender   proboscis  ^/a,°,  showing  venation. 

held  straight  out  in   front  of  the 

head  like  a  spear  at  rest  (Fig.  467).  But  this  beak  has  no  bloodthirstiness;  it 
is  used  to  suck  up  sweet  nectar  from  flower-cups.  The  larvae  of  the  bee-flies, 
however,  are  carnivorous,  Hving  parasitically  in  the  egg-cases  of  grasshoppers 
or  on  the  bodies  of  wild  bees  and  various  caterpillars.  One  of  these  bee- 
fly  larvas  burrowing  into  a  grasshopper's  egg-pod  can  do  awful  harm  to  the 
embryo  grasshoppers,  but  at  the  same  time  much  good  to  us,  by  the  satisfac- 
tion of  its  egg-eating  propensities.  Beautiful,  velvet-clothed,  swift-winged, 
and  nectar-feeding  as  a  fly,  maggot-Hke  and  parasitic  as  larva,  the  bee-fly 
is  a  good  example  of  the  great  differences  in  structure  and  habit  which  are 
possible  between  young  and  old  of  the  speciaHzed  insects. 

Bombylius  (Fig.  467)  is  a  genus  in  which  the  proboscis  is  very  long  and 
slender,  the  body  short  and  plump  and  covered  with  a  thick  soft  coat  of  longisb 


334 


The  Two-winged  Plies 


hair  usually  light  brown  or  whitish  in  color.  The  wings  are  blotched  with 
brown  or  blackish.  Anthrax  contains  numerous  species  with  short  proboscis, 
and  broad  flattened  body  covered  with  short  hair.  The  wings  are  either 
clear  or  partly  colored  with  brown  or  black.  In  the  species  of  the  genus 
Exoprosopa  (Fig.  468)  the  hair  of  the  body  is  very  short  and  often  in  silvery 

bands  across  the  abdomen,  the  pro- 
boscis is  short,  and  the  wings  usually 
beautifully  "pictured"  with  brown  and 
black. 


Fig.  467. 
Fig.   467. — A  bee-fly,    Bombylius  major 
Fig.  468. — A  bee-fly,  Exoprosopa  sp 


Fig.  468. 
(Twice  natural  size.) 
(One  and  one-half  times  natural  size.) 


In  California  the  roads  and  paths,  especially  along  streams  and  through 
woods  and  parks,  are  made  almost  intolerable  in  part  of  the  spring  for  driving 
or  bicychng  because  of  hosts  of  small  slender  blackish  flies 
in  swiftly  dancing  swarms.  These  are  dance  -  flies, 
Empididas,  and  their  aerial  dance  is  their  mating  flight. 
I  do  not  know  that  such  hordes  of  dance-flies  occur  in 
the  East,  but  some  species  of 
the  family  have  the  same  danc- 
ing habit  there,  and  can  be  dis- 
tinguished by  it  and  by  the 
structural  characters  given  in 
the  key.  The  midges,  Chirono- 
midae,  also  dance  in  swarms  in 
the  air,  but  are  readily  dis- 
tinguished from  the  Empidids 
by  their  small  fragile  body, 
and  long  many-segmented  hairy 
antennae.  All  the  dance -flies 
are  predaceous,  sometimes 
catching  their  prey  in  the  air, 
sometimes  chasing  it  on  the 
ground.    The  larvae,  slender  cylindrical  grubs  living  in  the  soil  or  under  leaves 


Fig.  469.  Fig.  470. 

Fig.  469. — Mouth-parts  of  a  bee-flv  Bombylius  sp 

(Much  enlarged.) 
Fig.  470. — A  dance-fly,  Rhamphomyia  longicauda 

(Three  times  natural  size.) 


The  Two-winged  Flies  nor 

or  other  vegetable  matter,  are  also  probably  predaceous,  feeding  on  smaller 
insects  living  in  the  same  places. 

The  commoner  species  that  dance  in  large  swarms  belong  to  the  genera 
Empis  and  Rhamphomyia  (Fig.  470).  The  males  of  certain  species  of  Empis 
and  Hilara  have  the  odd  habit  of  blowing  out  bubbles  of  a  whitish  viscid  sub- 
stance which  they  carry  about  with  them  in  the  air.  It  is  believed  that  these 
toy  balloons  are  attractive  to  the  females.  At  least,  Professor  Aldrich,  a 
well-known  student  of  flies,  has  seen  a  female  choose  that  male  among  several 
which  was  carrying  the  largest  balloon! 

An  attractive  lot  of  small  slender  flies,  usually  of  iridescent  green  or 
greenish-black  or  blue  color,  with 
unusually  long  slender  legs,  are 
the  Dohchopodidas,  or  long-legged 
flies.  They  are  found  especially 
in  marshy  or  low  places  where 
vegetation  grows  lush  and  rank. 
They  flit  about  searching  for 
lesser  insects,  which  they  catch 
and  devour.     They  often  get  their 


•    471-  — Diagram    of    wing    of   dance-fly, 
Rhamphomyia   sp.,   showing   venation. 


prey  by  swift  chasing  over  leaves  or  ground  or  even  on  the  surface  of  water. 
Like  the  Empidids  the  larvas  are  also  predaceous,  living  underground  or  in 
decaying  vegetable  matter.     Some  have  been  found  in  the  exuding  sap  of 


wjrf 


mjc 


Fig. 


Fig.  472.  Fij,   ^^^ 

472.— Mouth-parts   of   dance-fly,   Rhamphomyia  sp.     lb.,   labrum;  \,!x.,   maxilla; 
Ftp  "!^;  '  "^^  r  ^"I   ""Yi  f  ^•/'•'  "^^^^iHary  palpus;    li.,  labium;    hyp.,  hypopharynx. 
I'lG-  473-— Dohchopus  lobatus.     (Three  times  natural  size.) 


trees  and  elsewhere  on  or  under  bark.  The  larvae  of  certain  species  spin 
little  thin  cocoons  when  ready  to  pupate,  but  with  most  the  pupa  is 
naked. 


33^ 


The  Two-winged  Flies 


Dolichopus  (Fig.  473)  is  the  largest  genus  of  the  family,  nearly  100  species 
occurring  in  this  country.  The  males  are  curiously  ornamented  by  special 
outgrowths  or  expansions  on  the  feet.  These  make  the  feet  at  the  end  of 
the  long  legs  very  conspicuous  and  are  believed  to  serve  the  male  to  help 
attract  the  female  in  his  courtship  of  her.  These  ornaments  are  not  con- 
fined to  the  males  of  this  genus,  other  genera  of  the  family  showing  similar 


Fig.  474. — Diagram  of  wing  of  a   Dolichopodid,  Psilopics  ciliatus,  showing  venation. 


characters.  Other  ornaments,  too,  are  found  in  various  species,  some  occur- 
ring on  the  face,  others  on  the  antennae  and  elsewhere.  Aldrich  says  that 
the  males  of  the  flies  of  this  family  show  more  pronounced  and  various  special 
ornamentation  than  the  males  of  any  other  single  family  of  animals.  He 
has  seen  the  males  dangle  their  tufted  feet  in  the  faces  of  the  females  during 
courtship. 

Occasionally  the  general  collector  or  nature  observer  will  find  an  insect 
that  he  has  taken  at  first  glance  for  a  wasp,  but  which  on  examination,  after 
capture,  is  found  to  have  but  a  single  pair  of  wings,  and  short,  clubbed  anten- 
na; like  a  fly.  The  puzzle  is  readily  solved  with 
these  clues:  the  insect  is  a  fly,  not  a  wasp;  it  simply 
looks  so  much  hke  a  wasp  that  it  undoubtedly  is 
frequently  mistaken  for  a  wasp  by  certain  enemies 
which  are  afraid  to  attack  the  well-defended  hornet, 
but  would  make  short  work  of  a  defenceless  fly. 
The  wasp-flies,  Conopida;,  thus  save  their  lives  by 
an  innocent  deception;  they  are  protected  by  their 
curiously  close  mimicry  of  wasps.  All  of  them  are 
narrow-waisted,  and  most  have  the  abdomen  spindle- 
shaped  and  tapering  like  a  wasp's,  and  often  banded 
and  colored  so  as  to  increase  the  similitude.  All 
of  them,  too,  have  robust  heads  and  have  been  sometimes  called  "thick- 
head-flies." They  are  all  flower-flies,  feeding  on  nectar  and  pollen,  and 
hovering  on  heavy  wing  about  blossoming  shrubs.  The  oval  or  pear-shaped 
larvje  are  parasitic,  living  in  the  bodies  of  other  insects,  especially  wasps, 


Fig.  475.  — A  wasp-like 
Qy,PhysocephaIa  affinis. 
(One  and  one-half  times 
natural  size.) 


The-Two-winged  Flies  007 

bumble-bees,  and  locusts.  "The  eggs,"  according  to  Williston,  "are  laid 
directly  upon  the  bodies  of  the  bees  or  wasps  during  flight.  The  young 
larvae  burrow  within  the  abdominal  cavity  of  their  host  and  there  remain, 
the  posterior  end  directed  toward  the  base  of  the  abdomen,  feeding  upon 
the  non-vital  portions,  until  ready  to  transform  into  the  mature  fly,  when  they 
escape  from  between  the  abdominal  wings  of  the  insect.''  The  quiescent 
pupal  stage  is  then  passed  within  the  body  of  the  host,  a  rather  unusual 
phenomenon  in  insect  Hfe. 

In  the  genera  Conops  and  Physocephala  (Fig.  475)  the  abdomen  is  distinctly 
peduncled  as  in  the  thread-waisted  wasps,  while  in  Myopa,  Zodion,  Oncomyia, 
and  others  the  abdomen  is  sessile  or  constricted  only  at  the  very  base. 

Under  the  name  bot-flies  (CEstridae)  some  of  the  most  interesting  members 
of  the  order  Diptera  are  widely,  but  superficially,  known.  The  flies  themselves 
are  much  less  familiar  than  their  eggs  and  larvae,  the  glistening  white  eggs 
of  some  species  being  often  seen  attached  to  the  flanks,  legs, 
or  feet  of  a  horse  or  cow,  and  the  stomach-inhabiting  larvoe 
being  well  known  to  stockmen  as  the  cause  of  much  suffer- 
ing and  injury  to  their  animals.  In  addition  to  the  "bots" 
which  live  in  the  stomach  and  intestines  of  horses  and 
cattle,  several  other  species  live  under  the  skin  of  the  same 
animals,  as  well  as  of  goats,  sheep,  antelope,  rabbits,  rats.     Fig.  476.  —  Larva 

dogs,  cats,  and  even  man.     The  larvae  of  still  other  species      ?  "°^""7'  yj''^''^- 
°  '  '  ^  bra  cimtculi,  from 

burrow  in  the  nasal  passages  of  the  sheep,  the  antelope,  wood-rat,  Neoto- 
the  horse,  the  camel,  the  buffalo,  and  various  deer  species,  "f*^  ^P-  (Natural 
The  flies  are  heavy-bodied,  often  densely  hairy,  banded  in- 
sects, looking  rather  like  small  bumble-bees  whose  mouth-parts  are  so  atrophied 
that  they  can  probably  take  no  food  at  all.  They  lay  their  eggs  on  the  hairs 
or  skin  of  their  special  host  animal,  and  the  larvae  on  hatching  bore  directly 
through  the  skin  and  into  the  tissues  of  the  host,  or,  as  in  the  case  of  the 
familiar  bot-fly  of  the  horse  and  the  heel-fly  or  warble  of  cattle,  the  eggs  are 
taken  into  the  mouth  of  the  host  by  hcking,  swallowed,  and  thus  introduced 
directly  into  the  stomach,  to  whose  walls  the  larvae  either  attach  themselves  or 
through  which  they  burrow  into  the  true  body-cavity  of  the  host. 

Less  than  100  species  of  bot-flies  are  known  in  the  whole  world, 
but  the  parasitic  habits  and  resulting  economic  importance  of  these  flies 
have  resulted  in  making  the  family  well  known.  The  most  widely  dis- 
tributed and  best  known  species  is  probably  the  horse  bot-fly,  Gastrophiliis 
equi  (Fig.  477).  This  fly,  which  may  be  seen  in  open  sunny  places  along 
the  roadways,  is  about  ^  inch  long,  brownish  yellow,  with  some  darker 
markings,  but  much  resembling  a  honey-bee  in  appearance.  The  female 
has  the  abdomen  elongate  and  bent  forward  underneath  the  body.  The 
light-yellow  eggs  are  attached  by  a  sticky  fluid   to  the  hair  of  the  horse 


338 


The  Two-winged  Flies 


on  the  shoulders  or  legs  or  belly.  They  are  licked  off  by  the  horse  and 
swallowed,  and  the  larvae  hatch  in  the  mouth  or  stomach  and  attach  themselves 
to  the  stomach  lining,  living  at  the  expense  of  the  host.  When  many  larvae 
thus  live  in  the  stomach  (and  as  many  as  several  hundred  have  been  found 
in  one  animal)  the  horse  suffers  serious  injury.     The  larvae  live  in  the  stomach 


Fig.  477.- 


-Bot-fly  of  horse,  male,  Gastrophilus  eqiii,  abdomen  of  female  and  egg. 
Lugger;    natural  size  of  fly  indicated  by  line.) 


(After 


and  intestines  through  fall  and  winter,  and  late  in  the  spring  release  their 
hold,  pass  through  the  intestine  with  the  excretions,  and  burrow  into  the 
ground  to  pupate.  The  pupal  stage  lasts  about  a  month,  when  the  flies 
issue  and  the  life-cycle  begins  again.  A  smaller  species  of  bot-fly,  Gastro- 
philus nasahs,  with  bright-yellow  band  across  the  abdomen,  lays  its  eggs 
in  the  lips  and  nostrils  of  horses.  For  the  rest  its  life-history  is  about  like 
that  of  G.  equi. 

The  bot-flies,  warble-flies,  or  heel-flies  of  cattle,  whose  larvae  are  found  in 
small  tumors  under  the  skin,  also  have  their  eggs  swallowed,  and  the  young 
larvae  may  be  found  in  the  mouth  and  oesophagus.  But  from  here  they  burrow 
out  into  the  body-tissues  of  the  host,  finally  coming  to  rest  underneath  the 
skin  along  the  back.  When  the  larva  or  grub  is  full-grown  it  gnaws  through 
the  skin,  drops  to  the  ground,  pupates,  and  in  from  three  to  six  weeks  changes 
to  the  adult  fly.  The  hides  of  cattle  attacked  by  these  flies  are  rendered 
nearly  valueless  by  the  holes,  and  are  known  as  "grubby"  hides.  Osborn 
estimates  that  these  warble-flies,  of  which  we  have  two  species,  Hypoderma 
bovis  and  H.  lineata,  cause  a  loss  of  $50,000,000  annually  in  this  country. 

The  genus  Cuterebra  includes  a  number  of  species  of  which  the  rabbit 
bot-fly,  C.  cuniculi,  is  most  familiar.  The  larvae  lie  in  large  warbles  or  tumors 
under  the  skin  of  the  infested  rabbit,  and  late  in  the  summer  the  jack-rabbits 
and  cottontails  are  so  badly  infested  in  some  localities  that  hardly  one  can 
be  found  free  from  the  pest.     The  adult  is  a  large  fly  resembling  a  bumble- 


The  Two-winged  Flies  339 

bee,  with  black  head,  yellow-brown  thorax,  and  the  abdomen  blue-black 
with  yellow  base.     The  full-grown  larva  is  a  large  black  spiny  grub. 

One  or  two  species  of  bot-flies  infest  man,  and  also  (probably  the  same 
species)  monkeys  and  dogs  and  perhaps  other  animals.  Numerous  instances 
are  recorded  in  which  the  larvae  of  Dermatobia  noxialis  and  D.  cyaniventris 
have  been  found  under  the  skin  of  persons  in  tropical  America,  and  a  few 
instances  of  such  cases  in  the  United  States.  The  larvae  are  thick  and  broad 
at  one  extremity  and  elongate  and  tapering  at  the  other. 

The  family  SyrphidiE,  Syrphus-flies,  flower-flies,  or  hover-flies,  as  the 
Enghsh  call  them,  is  one  of  the  largest  in  the  order;  including  fully  2500 
species  in  the  whole  world,  of  which  over  300  are  found  in  this  country. 
For  so  large  a  family  few  generalizations  regarding  the  appearance  or 
habits  of  the  flies  can  be  made.  Many  of  the  Syrphus-flies  resemble  bees 
and  wasps  in  appearance,  and  almost  all  are  rather  bright  and  handsome 
insects.  They  feed  on  nectar  and  pollen,  and  hence  are  to  be  found  in  sun- 
shiny hours  at  flowers,  hovering  like  tiny  humming-birds  in  front  of  open 


Fig.  478.  Fig.  479. 

Fig.  478. — A  flower-fly,  Eristalis  tenax.     (One  and  one-half  times  natural  size.) 
Fig.  479. — Diagram  of  wing  of  Syrphus  continuax,  showing  venation. 

blossoms,  or  crawling  bee-like  in  and  out  of  deep  flower-cups.  Some  make 
a  distinct  humming  or  buzzing  as  they  fly  about  and  thus  heighten  their 
suggestion  of  bees.  All  can  be  distinguished,  after  capture,  by  the  so-called 
false  vein  of  the  wings  (see  Fig.  479).  The  larva?  live  variously  in  decaying 
wood  or  other  vegetation,  or  decomposing  flesh,  or  in  the  stems  of  green 
plants,  or  in  toadstools,  or  in  water.  Some  crawl  about,  slug-like  in  manner, 
over  leaves,  preying  on  aphids  and  scale-insects.  Some  live  as  guests  in  ants' 
nests,  and  others  in  the  underground  nests  of  bumble-bees. 

Those  Syrphid  larvae  most  often  written  about  are  the  curious  "rat-tailed 
maggots"  (Fig.  480),  larvae  which  live  in  stagnant  water  or  slime  and  have 
the  posterior  extremity  of  the  body  greatly  elongate  and  projecting  to  serve 
as  a  breathing-tube.  There  is  a  spiracle  (breathing-pore)  at  the  tip  of  this 
"tail,"  and  the  tail  projects  upward  so  that  its  tip  reaches  the  air,  while  the 
rest  of  the  larva's  body  remains  underneath  the  water.     The  larvae  of  Micro- 


34< 


The  Two-winged  Flies 


don,  which  live  in  ants'  nests,  look  like  little  mollu^s,  and  when  first  found 
were   actually   described   as   new   molluscous  genera.     Their   body  is  fiat. 


Fig.  480.  Fig.  481. 

Fig.  480. — Rat-tailed  larva  of  a  Syrphid.     (Twice  natural  size.) 
Fig.  481. — Larva  of  Microdon  miUabilis,  dorsal  view.     (Four  times  natural  size.) 

broad,  unsegmented,  and  looks  Hke  a  fiat  broadly  elliptical  little  shell  or 
plant-seed  (Fig.  481). 

Among  the  more  common  flies  of  this  family  which  may  be  taken  by  the 
collector  are  various  species  of  Eristalis,  with  black,  yellow,  and  amber  colors, 
heavy-bodied,  bee-like  forms,  and  especially  E.  tenax,  the  drone-fly,  which 
resembles  very  much  a  honey-bee  drone.  Its  larva  is  a  rat-tailed  maggot. 
The  species  of  Syrphus  are  black  with  yellow  bands,  with  the  abdomen 
not  so  heavy  as  in  Eristalis.  The  larvae  are  predatory,  doing  great  havoc 
in  aphid  colonies,  but  being  thus  of  great  benefit  to  florists  and  gardeners. 


Fig.  482. 


-Mouth-parts  of  Eristalis  sp.     li.,  labium;    hyp.,  hypopharynx;    Ih.,  labrum; 
mx.,  maxilla;    mx.l.,  maxillary  lobe;    mx.p.,  maxillary  palpus. 


The  species  of  Volucella  are  bee-like  in  appearance  and  their  larvae  live  in 
the  nests  of  bees,  but  whether  as  parasites  or  tolerated  guests  seems  not 
to  be  yet  known.  Sharp  thinks  that  they  act  as  scavengers  in  the  nests, 
and  thus  are  helpful  rather  than  harmful  to  their  hosts.  Syritta  pipiens  is 
a  common  Syrphid  fly,  with  slender,  elongate,  subcyUndrical  body,  blackish 
with  reddish-yellow  markings. 


The  Two-winged  Flies 


341 


The  abundant  house-flies  are  the  most  famihar  representatives  of  the 
largest  of  all  the  Dipterous  families:  largest  if  the  great  heterogeneous 
group  of  flies  called  Muscidae  is  to  be  looked  on  as  a  single  family,  a  point  of 
view  taken  by  some  entomologists,  but  not  so  if  this  group  is  called  a 
superfamily^  composed  of  a  large  number,  about  twenty  in  all,  of  distinct 
small  families.  The  group  includes,  besides  the  house-flies,  the  buzzing 
bluebottles,  the  disgusting  flesh-flies  and  stable-flies,  the  parasitic  Tachina 
flies,  the  pomace-flies,  fruit-flies,  grass-stem  flies,  brackish-water  flies,  and 
numerous  other  kinds  not  familiar  enough  to  have  a  vernacular  name.  To 
get  acquainted  with  some  of  the  more  abundant  and  interesting  kinds,  and 
to  enable  us  to  classify  them  to  subfamiHes  (if  the  whole  group  is  called 
family),  we  may  scrutinize  any  fly  which  our  key  on  page  332  leads  us  to 
call  a  Muscid,  in  the  hght  of  the  following  key: 

(The  first  posterior  cell  is  the  space  between  the  little  cross-vein  in  the  middle  of 
the  wing  and  the  outer  margin  of  the  wing.     See  in  Fig.  490.) 

Alulets  small Acalyptrate    Muscid.i;. 

Alulets    large Calyptrate     Muscid.e. 

First  posterior  cell  widely  open Subfamily  Anthomyiin.e. 

First  posterior  cell  narrowly  open  or  closed  (Fig.  490). 

Antennal  bristle  wholly  bare Subfamily  Tachinin.e. 

Antennal  bristle  with  some  distinct  hairs. 

Antennal  bristle  bare  near   the  tip Subfamily  Sarcophagin^. 

Antennal  bristle  plumose  or  pubescent  to  the  tip. 

Back  of  abdomen  bristly,  legs  unusually  long Subfamily  Dexiin.e. 

Back  of  abdomen  not  bristly,  except  sometimes  somewhat  so  near  tip. 

Subfamily    MusciN^. 

The  Acalyptrate  Muscidae  include  a  host  of  small,  mostly  unfamiliar, 
flies,  distributed  among  a  score  of  subfamilies.      We  shall  refer  to  a  few 


Fig.  483.  Fig.  484 

Fig.   483. — House-fly,   Musca  domestica.      (After  Howard     and    Marlatt;     three   times 

natural   size.) 
Fig.   484. — Foot   of  house-fly,    showing  claws,   pulvilli,   and   clinging  hairs.      (Greatly 

magnified.) 

of  the  more  interesting  kinds  in  the  group  after  taking  up  briefly  the  five 
subfamilies  of  larger,  more  noticeable  Calyptrate  Muscids. 


342 


The  Two-winged  Flies 


Most  abundant,  most  wide-spread,  and  most  important  to  us  of  all  the 
Muscid  flies  are  the  common  house-flies.  They  belong  with  some  other 
similar  forms  to  the  subfamily  Muscinas.  A  number  of  species  may  be 
found  in  houses,  but  the  true  house-fly,  Musca  domestica  (Fig.  483),  is  by 
far  the  most  numerous.  Dr.  Howard,  government  entomologist,  who  has 
paid  special  attention  to  the  life  of  house-flies  and  mosquitoes,  because  of 
their  dangerous  disease-germ  carrying  habits,  says  that  house-flies  undoubtedly 
contribute  materially  in  the  dissemination  of  infectious  diseases  by  carrying 
germs  in  the  dirt  and  filth  on  their  feet,  collected  during  their  pilgrimages 
to  the  contents  of  cuspidors,  slop-pails,  and  closets.  He  advocates  a  definite 
crusade  against  the  house-fly  like  the  one  now  being  undertaken  in  this 
country  against  the  mosquito. 


Fig.  4S5. 


Fig.  486. 


Fig.  485. — Larva   of  house-fly,  Musca  domestica.     (After  Howard   and   Marlatt;    three 

times  natural  size.) 
Fig.  486.^Pupa,   in  puparium,   of    house-fly,   Musca  domestica.      (After  Howard  and 

Marlatt;    three  times  natural  size.) 


The  eggs  of  the  house-fly  are  laid  in  horse-manure,  occasionally  in  other 
excrementitious  or  decaying  matter.  Each  female  lays  about  one  hundred  eggs. 
These  eggs  hatch  in  six  or  seven  hours,  and  the  slender  pointed  white  larvae 
called  maggots  (Fig.  485)  lie  in  their  plentiful  food-supply  for  the  five  or  six  days 
necessary  for  their  full  growth.     They  pupate  within  the  last  larval  skin,  which 

thickens  and  turns  brown  at  the  time  of  pupation 
(Fig.  486).  The  pupal  stage  lasts  five  days,  and 
then  the  fly  issues.  Its  food  is  liquid  and  taken 
up  by  lapping.  The  "house-fly"  that  bites  is 
not  the  true  house-fly,  but  usually  the  fiercely 
piercing  stable-fly,  Stomoxys  calcitrans,  another 
member  of  the  subfamily,  which  looks  much  like 
Musca  and  which  is  a  not  infrequent  visitor  in 
the  house. 

This  stable-fly  and   another  ally  of  the  house- 

moxys    calcitrans.    (Three   fly^  called  the  hom-fly,  are  great  pests  of  stock. 

The  horn-fly,  Hcematobia  serrata  (Fig.  488),  which 

gets  its  popular  name  from  the  habit  of  clustering,  when  not  feeding,  on  the 

bases  of  the  horns  of  cattle,  is  a  European  insect  that  was  accidentally  brought 

to  this  country  in  1886  or  1887. 

It  quickly  established  itself,  and  in  two  years  had  spread  over  the  eastern 


Fig.  487. — A   stable-fly,  Stp- 


The  Two-winged  Flies 


343 


states  so  widely  as  o  cause  much  alarm.  By  1895  i^  ^^^  spread  over  all 
of  the  United  States  east  of  the  Rocky  Mountains.  The  flies  pierce  the 
skin  and  suck  the  blood,  thus  causing  such  an  irritation  and  loss  of  blood 
that  the  affected  animals  cease  feeding  and  soon  show  great  loss  in  milk  or 
weight.  The  eggs  are  laid  in  fresh  cow-manure,  and  the  larvcc  become  full- 
grown  and  pupate  in  less  than  a  week.  The  pupal  stage  lasts  from  five 
to  ten  days.     Probably  half  a  dozen  generations  appear  annually.     Infested 


Fig. 


-The  horn-fly,  Hcsmatobia  serrata.     (After  Lugger;    natural  size  indicated 
by  Hne.) 


cattle  may  be  smeared  with  a  mixture  of  resh  oil  and  tar,  equal  parts,  which 
repels  the  flies,  and  lime,  which  kills  the  larvae,  may  be  thrown  on  the  manure. 
The  stable-fly,  like  the  house-fly,  lays  its  eggs  in  horse-manure,  and  Dr. 
Howard  foresees  a  curious  benefit  to  result  from  the  gradual  increase  in  the 
use  of  automobiles  in  cities,  and  the  corresponding  decrease  in  number  of 
horses  maintained,  in  the  gradual  doing  away  with  the  breeding-places  of 
house-flies  and  stable-flies. 

Next  to  house-flies  the  commonest  ones  about  houses  and  outbuildings 
are  the  bluebottles  and  blow-flies  or  flesh-flies.  These  all  lay  their  eggs 
or  deposit  living  larvae  on  meat,  and,  with  some  other  allied  species  which, 
however,  do  not  all  restrict  their  egg-laying  to  animal  substances,  belong 
to  the  subfamily  Sarcophaginas,  so  named  from  the  flesh-eating  habits  of  the 
larvae  or  maggots  of  the  best-known  species  The  most  abundant  flesh- 
fly  in  this  country  is  named  Sarcophaga  sarracenicc  (Fig.  489),  and  looks  like 
an  extra-large  house-fly.  It  gives  birth  to  larvae  (hatched  from  eggs  retained 
in  the  body  of  the  female)  which  are  deposited  on  fresh  meat,  sometimes  in 
open  wounds.  The  larvae  (maggots)  feed  and  grow  rapidly,  attaining  their 
full  .size  in  three  or  four  days.     They  pupate  within  the  thickened  brown  last 


344 


The  Two-winged  Flies 


larval  skin,  and  issue  as  adults  in  ten  or  twelve  days  after  birth.  The  blow- 
flies and  bluebottles,  members  of  this  subfamily,  have  the  body  steely  blue  or 
greenish  and  are  great  buzzers.  The  blow-fly,  Calliphora  erythrocephala, 
has  the  thorax  black  and  abdomen  steely  blue.  Its  eggs  are  laid  on  exposed 
meat,  fresh  or  decaying,  such  egg-infested  meat  being  called  ''blown."     The 


Fig.  480. — . 


A  blow-fly  or  flesh-fly,  SarcopJiaga  sarracenicB. 
indicated  by  line.) 


(After  Lugger;    natural  size 


larvae  feed  on  the  juices  of  the  decaying  meat  and  pupate  after  a  few  days. 
The  pupae  enclosed  in  the  thickened  brown  last  larval  skin  look  like 
large  smooth  shiny  brown  elliptical  seeds,  as  do  indeed  the  pupa?  of  all 
Calyptrate  ^luscidie.     The  commonest  bluebottle-  or  greenbottle-fly  is  Lucilia 

ccBsar,  which  lays  its  eggs  in 
cow-dung  as  well  as  on  flesh, 
and  which  often  comes  into 
houses,  particularly  before  rain. 
A  flesh-fly  of  serious  importance 
is  the  terrible  screw-worm  fly, 
Compsomyia  macellaria,  which 
lays  its  eggs  on  flesh,  manure,  in 
open  wounds,  and  often  in  the 


Fig.    490. — ^Diagram    of   wing   of   Lucilia   casar, 
showing  venation. 


nasal  passages  of  domestic  animals  and  human  beings,  entering  the  nose  for 
this  purpose  while  the  unfortunate  person  or  animal  is  asleep.  Numerous 
frightful  cases  of  such  attacks  on  persons  are  recorded,  especially  from  the 
southern  states.     The  lar\-a?  fairly  eat  away  the  whole  inner  nose  and  upper 


The  Two-winged  Flies  345 

pharynx,  causing  terrible  pain  and  sometimes  death.  Indeed,  out  of  twelve 
cases  which  came  to  the  knowledge  of  Dr.  Richardson,  an  Iowa  physician, 
eleven  resulted  fatally.  As  many  as  three  hundred  screw-worms  were  taken 
from  the  inner  nose  and  region  above  and  behind  the  soft  palate  of  some 
of  the  patients.  As  a  pest  of  domestic  animals  the  greatest  injuries  have  been 
caused  in  Texas.  The  eggs  are  laid  in  any  open  wound  or  in  the  nose  or  mouth, 
and  the  quickly  hatching  larvae  burrow  into  the  adjacent  tissues.  Cattle  and 
hogs  are  particularly  attacked,  horses  and  sheep  less  often. 

In  the  states  in  which  sugar-beets  are  grown  some  anxiety  for  the  success 
of  this  new  industry — new  in  this  country,  that  is;  sugar  has  long  been  made 
from  beets  in  Germany — is  felt  because  of  the  presence  in  the  beet-fields 
of  an  obscure  little  fly,  Pegomyia  vicina,  which  maybe  called  the  sugar-beet 
midge.  The  eggs  are  laid  on  the  leaves,  and  in  three  or  four  days  the  tiny 
white  larvae  hatch  and  burrow  into  the  soft  leaf-tissue.  When  many  of  the 
larvae  are  at  work  mining  the  leaves  much  injury  to  the  plants  results.  In  the 
great  sugar-beet  fields  along  the  California  coast  four  or  five  generations 
of  this  fly  appear  annually  and  occasion  great  loss  to  the  growers.  This 
fly  belongs  to  the  subfamily  Anthomyiinae,  to  which  Muscid  group  two 
other  well-known  fly-pests  belong,  namely,  the  onion-fly,  Phorhia  ceparum, 
and  the  cabbage  maggot-fly,  Phorbia  brassicce.  Both  these  insects  in  the 
adult  stage  are  small  light-gray  flies,  looking  rather  like  small  house-flies. 
The  onion-fly  lays  its  eggs  on  the  stems  of  onion-plants,  near  the  soil,  and 
the  hatching  larvae  burrow  into  the  underground  bulb,  which  they  soon 
nearly  destroy.  This  fly  appears  to  live  on  no  other  plant.  The  cabbage 
maggot-fly  lays  its  eggs  also  on  the  stem  just  above  or  even  below  the  ground, 
and  the  larvae  burrow  into  the  roots.  Cauliflowers  as  well  as  cabbages 
are  attacked,  and  often  tens  of  thousands  of  acres  of  these  two  vegetables 
are  destroyed  in  a  single  season  by  this  little  fly.  The  best  remedy  is  the 
use  of  cards  cut  from  tarred  paper  and  bound,  collar-like,  around  the  stems 
of  the  plants.  These  protecting  collars  should  be  put  on  when  the  young 
plants  are  transplanted  from  the  cold  frames  into  the  field.  Another  familiar 
member  of  this  subfamily  is  the  little  house-fly,  Homalomyia  caniailaris , 
smaller,  paler,  and  more  conical  in  shape  than  the  true  house-fly. 

Every  one  who  has  undertaken  to  rear  butterflies  and  moths  from  their 
caterpillars  has  been  compelled  to  make  the  acquaintance  of  certain  heavy- 
bodied  bristly  flies  which  appear  now  and  then  from  a  cocoon  or  chrysalid 
in  place  of  the  expected  moth  or  butterfly.  These  are  Tachina-flies,  and  in 
their  appearance  and  parasitic  habits  are  representative  of  the  large  sub- 
family of  house-fly  cousins  known  as  Tachiniinae.  The  females  fasten  their 
eggs  to  the  skin  of  young  caterpillars,  the  hatching  larvae  burrow  into  the 
body  of  their  crawhng  host  and  feed  on  its  body-tissues  Sometimes  the 
caterpillar  is  killed  before  it  can  pupate,  but  usually  not,  spinning  its  cocoon 


146 


The  Two-winged  Flies 


and  pupating  with  its  fatal  parasites  still  feeding  inside.  But  the  butterfly 
never  issues:  in  its  place  buzz  out  several  of  these  bristly  Tachina-flies. 
While  their  habits  arouse  our  indignation  at  first  acquaintance,  and  par- 
ticularly if  we  have  set  our  hearts  on  rearing  a  rare  moth  or  butterfly,  a 
moment's  reflection  assures  us  of  the  immense  good  these  flies  must  really 
do.  Howard  tells  of  an  instance  observed  by  him  where  the  buzzing  of 
the  swarms  of  Tachina-flies,  hovering  over  and  laying  their  eggs  on  the 
hosts  of  a  great  army  of  army-worms,  could  be  heard  for  a  long  distance. 


Fig.  491. 


Fig.  492. 


Fig.  491. — A  Tachina-fly,  Dejeania  corpulenta.       (One  and  one-half  times  natural  size.) 
Fig.  492.— Tachinid  parasite  (at  left)  of  the  California  flower-beetle,  and  parasitic  fungus, 
Sporotrichum  sp.  (at  right)  of  same  beetle.     (Slightly  enlarged.) 


He  says  that  a  great  outbreak  of  army-worms  in  northern  Alabama  in  1881, 
when  all  crops  were  threatened  with  total  destruction,  was  completely  frus- 
trated by  Tachina-flies.  These  parasites  also  attack  locusts,  leaf-eating 
beetles,  and  many  other  injurious  insects  besides  caterpillars,  and  altogether 
do  much  to  keep  in  check  some  of  our  worst  insect-pests.  A  single  species 
of  Tachina-fly  (Fig.  492)  is  almost  the  only  check  on  the  destructive  flower- 
eating  Diabrotica  {D.  soror)  of  California,  which,  if  allowed  to  increase 
unhindered,  would  soon  destroy  every  blossom  in  this  land  of  flowers. 

Resembhng  somewhat  in  appearance  the  Tachina-flies  are  the  so-called 
nimble-flies,  constituting  the  small  subfamily  De.xiince.  Most  of  the  species 
in  this  country  belong  to  the  single  genus  Dexia  and  have  been  little  studied. 
The  larvae  seem  to  be  all  parasitic,  although  the  life-history  of  no  species  has 
been  wholly  worked  through  yet.  Beetles  and  snails  seem  to  be  the  favorite 
hosts  of  these  flies. 

In  the  large  group  of  flies,  some  dingy  and  obscure  in  coloration,  others 
brightly  colored  and  with  beautifully  patterned  wings,  but  all  small  and 
most  unfamiliar,  called  the  Acalyptrate  Muscidae  (that  is,  the  house-fly 
allies  with  small  alulets),  we  shall  not  attempt  to  distinguish  the  vari- 
ous   subfamilies  as  we  have   for  the   Calyptrate  Muscids.        Dipterologists 


The  Two-winged  Flies 


347 


recognize  some  twenty  distinct  subfamilies  (or  families,  if  the  group 
Muscidse  be  looked  on  as  a  super-family)  of  these  small  flies,  but  the  distinc- 
tions are  quite  too  fine  for  the  general  collector  to  handle.  I  shall  therefore 
simply  refer  briefly  to  a  few  of  the  more  interesting  or  abundant  or  economi- 
cally important  species  in  this  group. 


Fig.  493. — Red-tailed  Tachina-fly,  Winthemia  4-pustnluta,  a  parasite  of  the  army-worm, 
Leucania  unipuncta.  a,  fly,  natural  size;  b,  fly,  enlarged;  c,  army-worm,  natural 
size,  upon  which  eggs  have  been  laid;  d,  parasitized  army-worms,  enlarged.  (After 
Slingerland.) 

Of  interest  because  of  the  extraordinary  condition  of  their  eyes  are  the 
blackish  flies  called  Diopsidae,  which  have  the  eyes  on  conspicuous  elon- 
gate lateral  processes  of  the  head.  These  eye-stalks  bear  also  the  antennae. 
Only  a  single  species,  Sphyracephala  brevicornis,  has  been  found  in  this 
country,  and  regarding  its  life-history  nothing  is  known.  The  flies  are  to  be 
looked  for  in  woodsy  places,  and  particularly  on  the  leaves  of  skunk-cabbage. 

In  the  water  and  cast  up  in  masses  along  the  shores  of  Mono  Lake  and 
certain  other  similar  brackish-water  lakes  in  the  desert  land  just  east  of 
the  Sierra  Nevada  Mountains  in  CaHfornia  may  be  found,  at  certain  seasons 
of  the  year,  innumerable  larvc-e  of  a  small  predaceous  fly  of  the  genus  Ephydra. 
These  dead-sea  waters  support  hardly  any  other  animal  life,  but  this  fly 
finds  the  water  much  to  its  liking  and  breeds  there  with  extraordinary  fecun- 
dity. The  Pai  Ute  Indians  of  this  region,  who,  like  the  flies,  have  a  ques- 
tionable palate,  gather  these  larvae  by  the  bushel,  dry  them  in  the  sun,  and 
use  them  for  food  under  the  name  koo-chah-bee.  Prof.  Brewer  of  Yale, 
who  made  a  trial  of  koo-chah-bee,  says  "it  does  not  taste  badly,  and  if  one 


348 


The  Two-winged  Flies 


were  ignorant  of  its  origin  it  would  make  a  nice  soup."     Other  species  of 
Ephydridae  occur  abundantly  in  salt-water  marshes,  the  flies  living  a  preda- 


FlG.  494. 


Fig.  495. 


Fig.  494. — Scatophaga  sp.     (Two  and  one-half  times  natural  size.) 
Fig.   495. — An    aquatic    muscid,    Tetanocera  pictipes,   larva,    pupa,    and    adult. 
Needham;    two  and  one-half  times  natural  size.) 


(After 


tory  life  and  doing  much  to  reduce  the   numbers  of  brackish- water  mos- 
quitoes and  other  small  insect-pests. 

One  of  the  great  packing-houses  of  Kansas  City,  Missouri,  once  called  in 
an  entomologist  to  aid  it  in  fighting  a  little  fly  which  was  causing  the  packers 
a  loss  of  many  thousand  dollars  annually.  This  was 
the  cheese-skipper  fly,  Piophila  casei  (Fig.  496),  which 
might  almost  as  well  be  called  the  ham-  and  bacon- 
skipper  fly,  for  the  eggs  are  laid  quite  as  willingly 
on  any  smoked  meat  as  on  cheese.  In  the  packing- 
house swarms  of  the  flies  were  buzzing  about  at 
the  mouth  of  the  great  smoke-shaft  from  which  the 
hams  and  pieces  of  bacon  were  being  constantly 
taken  to  be  wrapped  and  made  ready  for  shipping. 
These  flies  would  dart  down  and  lay  their  eggs  on  the 
smoked  meat  while  actually  in  the  wrapper's  hands, 
and  thus  thousands  of  egg-blown  hams  and  bacon 
sides  would  be  wrapped  and  sent  out.  When  the  cook  a  thousand  miles 
away  tears  the  wrappings  from  a  "piophilized"  ham  he  quickly  sends  in 
an  indignant  report  to  his  local  meat-supplier,  who  in  turn  makes  a  protest 
to  the  packer.  In  time  the  packer  calls  for  help  from  an  entomologist. 
The  larvae  of  this  fly  have  the  odd  habit  of  bending  nearly  double  and 
then  with  a  quick  straightening  they  throw  the  body  some  inches  into  the 
air.     Hence  the  name  skipper,  commonly  applied  to  it. 


Fig.  496. — The  cheese- 
skipper  fly,  Piophila 
casei.  (Five  times 
natural  size.) 


The  Two-winged  Flies 


349 


At  cider-making  and  fruit-gathering  time,  and  in  vine-growing  districts 
at  wine-making  time,  hosts  of  tiny  yellowish-bodied  flies,  the  pomace-flies  or 
fermenting  fruit-flies,  Drosophihdae,  may  be  seen  busily  lapping  up  their 
favorite  food,  the  juices  of  fermenting  fruits. 
The  most  abundant  and  wide-spread  species 
is  Drosophila  ampelophila,  the  vine-loving 
pomace-fly.  It  is  a  small,  clear-winged, 
red-eyed,  brownish-yellow,  chubby  fly 
which  lays  its  eggs  on  gathered  fruits, 
and  especially  decaying  fruit  and  pomace, 
and  also  on  grapes  still  hanging  on  the 
vines  if  they  have  been  broken  somewhat 
by  birds.  The  larva  or  maggots  hatch  in 
from  three  to  five  days,  live  in  the  fruit  four  days,  and  lie  in  the  pupal 
stage  three  to  five  days,  so  that  a  whole  life-cycle   is   gone  through  in  less 


Fig.  497. — Trypeta  longipennis.  (Two 
and  one-half  times  natural  size.) 


Fig.  498  — Larva  of    cherry-fruit    fly,   Rhagoletis    cingiihta,  dorsal    and    lateral  views. 
(After  Slingerland;    natural  size  and  much  enlarged.) 


35^ 


The  Two- winged  lilies 


than  two  weeks.     Thus  e\'en  in  the  short  season  of  the  fruit  ripening  and 
gathering  much  injur}-  can  be  and  often  is  done  by  these  little  tipplers. 

A  much  larger  group  of  fruit-flies  is  the  Trypetidas,  whose  larvae  burrow 
in  fruits  or  plant-stems,  often  producing  galls  on  these  latter.  The  familiar 
spherical  swelling  or  gall  on  goldenrod  stems  is  the  hiding  and  feeding  place 


Fig.  499. — Pupari;i  of  cherry-fruit  fly,  Rliugoletis  cingiilata.     (After  Slingerland;    natural 

size  and  much  enlarged.) 

of  the  thick  white  larvae  of  Trypeta  solidaginis,  a  pretty  fly  with  banded 
wings.  The  longer  hollow  gall  which  sometimes  occurs  on  goldenrod 
is  made  by  the  caterpillar  of  a  small  moth,  Gelechiq  gallcE-solidaginis. 
Some  Trypetid  species  do  much  injury  by  burrowing  into  fruit,  as  the  apple- 
maggot,  and  the  larva  of  a  black-and-white  fly  with 
banded  wings  known  as  Trypeta  liidens,  whose 
larvK  infests  Mexican  oranges  and  may  sometime 
get  a  foothold  in  Cahfornia  or  Florida. 

Another  group  of  small  flies  whose  larvae  are 
responsible  for  serious  injury  to  growing  grain, 
meadows,  and  pasture  grasses  are  the  Oscinidae, 
or  grass-stem  flies.  The  adults  are  commonly  taken 
by  collectors  when  beating  or  sweeping  in  meadows 
Fig.     500.  —  An     aquatic    and  pastures.      The  flies   are    minute  but   plump, 

muscid,    Sepedon    fasa-    ^^^^    ^j.^     variously    colored,    sometimes    blackish, 

pennis,  larva,  pupa,  and  .  . 

adult.    (After  Needham ;    Sometimes  yellowish.     They  are   so  small  that  they 

two  and  one-half  times    often  get   into  one's  eyes  in  their  swarming-time, 

and  are   said  to    cause  a  prevalent  disease  of  the 

eyes  in  the  South.     The  thick  cylindrical  little  larvae  of  several  species  of 

Oscinis  hve  in  the  stems  of  wheat,  barley,  oats,  rye,  and  grass.     The  larva 

of   Chlorops   similis   burrows    in    the    leaves   of    sugar-beets,  and    another 


The  Two-winged  Flies  351 

species  of  the    genus  is    the    notorious   "frit-fly,"   one   of   the   chief   grain- 
pests  of  Europe. 

SUBORDER    PUPIPARA. 

Bird-collectors  occasionally  find  on  their  sj)ecimens  curious  flat-bodied 
insects  with  leathery  skin  and  a  single  pair  of  wings,  which  are  obviously 
parasites  on  the  body  of  the  birds.  Owls  and  swallows  seem  especially 
infested.  Similar  parasitic  insects,  but  wingless,  are  also  found  on  sheep,  and 
a  winged  form  is  not  uncommon  on  horses.  These  degraded  insects  are 
flies  of  the  suborder  Pupipara  which  are  commonly  known  as  bird-ticks, 
sheep-  and  horse-ticks,  etc.  The  animals  more  rightly  entitled  to  the  name 
"ticks"  are  really  not  true  insects,  but  belong  with  the  scorpions,  spiders, 
and  mites  in  the  class  Arachnida.  They  have  four  pairs  of  legs  and  are  always 
wingless.  Such  true  ticks  are  the  leathery-skinned  cattle-ticks,  dog-ticks, 
and  wood-ticks. 

The  degraded  Diptera  belonging  to  the  suborder  Pupipara,  and  also 
called  ticks,  have  of  course  three  pairs  of  legs  and  some  are  winged.  Their 
name  Pupipara  comes  from  the  curious  circumstances  of  their  birth.  The 
female  does  not  deposit  eggs  outside  her  body,  but  gives  birth  to  young  which 
are  just  ready  to  assume  the  pupal  stage  at  the  time  of  their  appearance. 
In  the  case  of  one  species,  the  sheep-tick  (Melophagus),  whose  development 
has  been  carefully  studied,  the  female  has  four  egg-tubes  each  of  which 
produces  a  single  germ-cell  at  a  time.  Of  these  four  egg-cells  three  remain 
small,  while  one  becomes  large  and  develops  into  an  embryo.  This  embryo 
lies  in  the  unpaired  wide  vagina  of  the  female,  soon  casts  ofT  its  egg-envelopes, 
and  is  nourished  as  a  growing  larva  by  a  secretion  from  two  pairs  of  glands 
opening  into  the  vagina  of  the  mother.  Here  the  headless,  footless  larva 
lies  and  grows  until  it  is  about  ^  inch  long,  when  it  is  born  and  immediately 
pupates.  The  development  of  the  other  Pupipara,  as  far  as  studied,  is 
similar  to  that  of  the  sheep-tick. 

The  suborder  includes  three  famihes,  as  follows: 

With  compound  eyes;   sometimes  with  wings. 

(Bird-,  sheep-,  and  horse-ticks.)     Hippoboscid^. 
Without  compound  eyes,  always  wingless. 

Halteres    present;     on    bats (Bat-ticks.)     Nycteribiid^. 

Halteres  absent;  on  honey-bees (Bee-lice.)     Braulid^. 

Of  the  Hipposcida;  the  sheep-tick,  Melophagus  ovinus,  already  referred 
to,  is  common  and  familiarly  known.  It  is  wingless,  and  can  crawl  readily 
about  through  the  wool  next  to  the  skin.  With  its  strong  proboscis,  com- 
posed of  two  hard  pointed  flaps,  it  punctures  the  skin  and  sucks  blood  from 
its  host's  body.  The  horse-tick,  Hippobosca  equina  (Fig.  501),  is  winged. 
There  are  several  species  of  this  family  found  on  birds.     Oljersia  americana 


352 


The  Two-winged  Flies 


is  a  yellowish  winged  species  common  on  owls,  some  hawks,  and  the  ruffed 
grouse.  Swallows  are  often  infested,  and  I  have  taken  bird-ticks  from  half 
a  dozen  other  kinds  of  birds.  A  careful  search  for  these  curious  insects 
will  certainly  make  known  numerous  new  species. 


(.-Xfter    Lugger;    natural 


Fig.  501. — A  horse-tick    or    forest-fly,    Hippohosca    equina. 

length  J  to  J  inch.) 

The  genus  Lipoptena  includes  a  few  known  species  found  on  mammals 
which  are  winged  for  awhile,  but  later  cast  or  bite  off  the  wings.  They 
probably  fly  about  in  their  search  for  a  host,  after  finding  which  they  remove 
their  wings  and  remain  for  the  rest  of  their  life  on  this  host  individual.  Lip- 
optena cervi  is  a  species  found  on  deer. 


Fig.  504. 

Fig.  502.  Fig.  503.  pic.  -03.  Bat-tick,  Nycterihia  sp. 

Fig.  502. — Sheep-tick,  Melophagus  ovinus.  Nat.  size  \  in. 

Fig.  504. — A  bee-louse,  Braula  sp.     (After  Sharp;   much  enlarged.) 

The  bat-ticks,  Nycteribiidse  (Fig.  503) ,  are  curious  long-legged,  wingless, 
small   spider-like  creatures  about  \  inch  long  or  less,  which   look  as  if  the 


The  Two-winged  Flies  353 

upper  were  the  under  surface.  The  head  is  narrow  and  Hes  back  on  the 
dorsum  of  the  thorax,  and  the  pro  thorax  rises  from  the  upper  instead  of 
anterior  aspect  of  the  mesothorax.  They  are  found  only  on  bats  and  are  not 
common. 

The  strange  minute  insect,  jV  inch  long,  found  clinging  to  the  thorax 
of  queen  and  drone  honey-bees  and  known  as  the  "bee-louse,"  Braula 
ca'ca  (Fig.  504),  is  the  only  species  known  of  the  family  Braulidae.  Its  legs 
are  rather  short  and  stout,  and  each  ends  in  a  pair  of  comb-like  brushes. 

ORDER    SIPHONAPTERA. 

The  fleas  are  blood-sucking  parasites  of  mammals  and  birds  which  were 
long  classified  as  a  family  (Pulicidae)  of  the  Diptera,  being  looked  on  as 
wingless  and  otherwise  degenerate  flies.  But  they  are  now  given  by  ento- 
mologists the  rank  of  an  order,  called  Siphonaptera,  subdivided  into  three 
famihes  of  its  own.  Nearly  one  hundred  and  fifty  species  of  fleas  are  known 
in  the  world,  of  which  about  fifty  are  recorded  from  this  country.  They  have 
been  taken  from  the  domestic  dog,  cat,  rat,  and  fowls,  and  from  various  wild 
animals,  such  as  several  rabbit  and  squirrel  species,  the  lynx,  weasel,  mole, 
mountain-rat,  shrews  and  mice,  prairie-dog,  woodchuck,  opossum,  etc. 
Rothschild  has  recently  described  a  new  flea  species  from  the  grizzly  bear 
(British  Columbia).  But  from  the  great  majority  of  our  wild  mammals  fleas 
have  not  yet  been  recorded,  although  undoubtedly  most  of  them  are  infested. 
Baker,  who  has  recently  published  a  monograph*  of  the  known  North 
American  species,  suggests  that  particularly  interesting  forms  will  probably 
be  found  on  bats.  One  flea  species,  Pulex  avium,  has  been  taken  from  several 
kinds  of  birds,  and  two  or  three  other  fleas  are  recorded  from  bird  hosts. 

The  'pecuhar  structural  characteristics  of  fleas  are  their  winglessness, 
the  extraordinary  lateral  compression  of  the  body,  and  the  curious  modifica- 
tion of  their  mouth-parts  for  effective  piercing  and  blood-sucking.  The  an- 
tenna lie  in  little  half-covered  grooves,  extending  down  and  back  behind 
the  eyes;  they  can  be  lifted  or  stretched  up  whenever  needed.  Each  antenna 
is  composed  of  three  segments,  the  terminal  one,  however,  being  spirally  or 
transversely  lined  or  grooved  and  variously  shaped,  so  that  it  appears  to  be 
composed  of  several  segments.  The  mouth-parts  consist  of  a  pair  of  needle- 
like mandibles,  a  pair  of  slender  grooved  labial  processes,  probably  the 
palpi,  a  pair  of  short,  broad,  flattened  maxillae,  each  with  a  short  antenna- 
like palpus  at  its  tip,  and  an  unpaired  needle-like  hypopharynx.  The  needle- 
like parts  serve  for  piercing  and  the  grooved  labial  processes  for  sucking. 
Regularly  arranged  over  the  body  are  (in  most  fleas)  many  series  of  stiff, 
spine-like  hairs,  often  unusually  conspicuous  and  strong  on  the  head  and 

*  Baker,  C.  F.  A  Revision  of  American  Siphonaptera.  Proc.  U.  S.  Nat.  Mus.,  vol. 
xxvii,   1904,  pp.  365-469. 


354 


The  Two-winged  Flies 


thorax.  The  head  is  ridiculously  small  and  malformed,  so  that  a  flea  under 
the  microscope  always  suggests  an  idiotic  (microcephalous)  creature.  But 
if  its  insidious  attack  and   brilliant  tactics  in  retreat  be  due  to  wit,  this 


Fig.  505. — Dog-  and  cat-flea,  Ctenocephalus  canis.     (After  Lugger;  much  enlargeci.) 

small-headedness    is    truly    deceptive.     However,    our   modern    mechanical 
theories  of  reflex  action,  negative  phototropism   (repulsion  by  light),  etc., 


Fig.  506. — The  house-flea,  Pw/ex ^Vritew5.    ^,  larva;  5,  pupa;  C,  adult. 
(After  Beneden;   much  enlarged.) 

allow  r.s  to  give  the  elusive  flea  little  credit  for  its  ingenuity;   we  must  look 
on  it  ..s  an  unusually  well-made  and  smoothly-working  organic  machine. 


The  Two-winged  Flies  355 

While  the  adult  fleas  are  commonly  seen,  particularly  in  lands  of  soft 
climate,  like  Italy  and  California,  in  immature  form  these  insects  are  wholly 
unfamiliar.  The  larva)  (Fig.  506)  are  small,  slender,  white,  footless,  worm- 
like grubs,  with  the  body  composed  of  thirteen  segments,  the  first  being  the 
small  brown  head  bearing  short  antenna)  and  biting  mouth-parts,  but  no 
eyes.  The  larvce  seem  to  live  on  dry  vegetable  dust,  the  excreta  of  adult 
fleas,  and  other  organic  detritus.  The  larval  life  varies  much  in  duration 
in  different  species,  and  even  in  the  same  species  under  varying  conditions. 
In  our  commonest  species,  the  cat-  and  dog-flea,  Pergande  has  found  the 
larval  hfe  to  last  only  one  or  two  weeks,  the  whole  development  from  egg  to 
adult  being  completed  sometimes  in  a  fortnight.  When  full-grown  the 
larva  spins  (usually)  a  thin  silken  cocoon  in  the  dust  or  htter  in  which  it  hes, 
within  which  it  pupates. 

The  parasitic  habits  of  fleas  vary  from  a  very  temporary  character  to  one 
approaching  permanence.  In  such  forms  as  the  human  flea  and  the  dog- 
flea  no  stage  of  the  immature  life  is  passed  on  the  body  of  the  host  (although 
the  eggs  of  the  dog-flea  are  usually  laid  on  the  hairs  of  the  host,  but  so  loosely 
attached  that  they  fall  off  before  the  larvae  emerge),  but  in  the  burrowing 
kinds  hke  the  "chigoe"  or  "jigger,"  where  the  females  become  completely 
encysted  in  the  skin  of  the  host,  the  young  hatch  in  the  tumor,  and  unless 
carried  out  by  pus  probably  develop  there.  But  taken  altogether  the  fleas 
are  to  be  considered  as  belonging  to  the  category  of  "temporary  external 

parasites." 

The  species  known  in  this  country  represent  two  families  which  may  be 
separated  by  the  following  key: 

Small  fleas  with  proportionally  large  head ;  female  a  stationary  parasite  with  worm- 
like or  spherical  abdomen,  burrowing  into  flesh  of  the  host;  labial  palpi 
i-segmented;     no    "combs"   of   spines   on   head,    thorax,    or   abdomen. 

Sarcopsyllid^. 

Larger  fleas  with  proportionally  small  head;  adults  active  temporary  parasites, 
with  abdomen  always  compressed;  labial  palpi  3-  to  5-segmented;  head, 
thorax,  or  abdomen  often  with  "combs"  of  spines Pulicid.^. 

Of  the  SarcopsyUida)  but  two  genera  are  known,  one,  Sarcopsylla,  includ- 
ing the  common  jigger-flea,  infesting  various  mammals  and  man  in  the 
tropics  and  probably  occurring  in  Florida  and  southern  Texas,  and  Xes- 
topsylla,  the  common  chicken-flea,  being  distinguished  by  having  the  head 
not  angularly  produced. 

The  jigger-flea,  or  chigoe,  Sarcopsylla  penetrans  (not  to  be  confused  with 
a  minute  red  mite,  common  on  lawns,  which  burrows  into  the  skin  and  is 
also  called  "jigger"  or  "chigger"),  was  described  by  Linnaeus  in  1767  and 
has  been  commonly  known  as  a  pest  of  man  in  tropical  and  sub-tropical 
countries  ever  since.     It  also  infests  many  domestic  animals,  as  the  dog,  cat, 


35^  The  Two-winged  Flies 

horse,  cow,  sheep,  etc.,  as  well  as  birds.  The  male  jigger-fleas  hop  on  or 
off  the  host  as  other  fleas  do,  but  the  females,  when  ready  to  lay  eggs,  burrow 
into  the  skin,  especially  that  of  the  feet,  and  produce  a  swelhng  and  later 
a  distinct  ulcer,  sometimes  so  serious  as  to  result  fatally.  The  remedy  is 
(as  also  for  the  chigger-mite)  the  pricking  out  entire,  with  a  needle  or  knife- 
point, of  the  pest  as  soon  as  its  presence  is  detected.  The  bursting  of  the 
body  of  the  female  in  the  skin,  with  the  release  of  its  eggs,  is  likely  to  result 
seriously.  When  domestic  animals  are  attacked  it  is  difficult  to  fight  the 
pest.  The  liberal  use  of  pyrethrum  on  the  rubbish  or  dust  in  which  the 
young  stages  are  developing  is  recommended.  The  hen-flea,  XestopsyUa  gal- 
linacea,  first  described  from  Ceylon,  sometimes  becomes  a  serious  pest  of 
fowls  in  warm  regions.  The  females  of  the  hen-flea  burrow  into  the  skin  of 
the  fowl  and  lay  their  eggs  in  the  small  tumor  which  forms  about  them. 
This  pest  has  been  known  in  the  Southern  United  States  since  about  i8go 
and  is  a  common  pest  from  Florida  to  Texas. 

The  second  family,  Pulicidae,  includes  all  the  other  fleas,  none  of  which 
burrows  into  the  skin.  The  various  species  range  in  size  from  ^^  inch  (Anomi- 
opsylhis  niidatus,  found  on  a  mouse  in  Arizona)  to  \  inch  {Ceratophyllus 
stylos  Its,  taken  from  Haplodon  in  Oregon),  but  all  fairly  similar  in  shape 
and  appearance  to  the  familiar  house-fleas.  They  are  grouped  in  nine 
genera,  of  which  Pulex  is  much  the  largest  and  includes  the  human  flea 
and  the  cat-  and  dog-flea,  the  two  species  to  which  the  house-infesting  pests 
belong.  The  human  flea,  Piilex  irritans,  was  described  by  Linnaeus  in 
1746.  It  is  known  all  over  the  world,  and  often  becomes  a  serious  pest. 
In  this  country  it  is  probably  not  so  commonly  met  with  in  houses  as  the 
cat-  and  dog-flea,  Ctenocephalns  canis,  from  which  it  may  be  readily  dis- 
tinguished by  its  lack  of  combs  of  spines  on  the  back  of  the  head  and 
prothorax.  The  eggs  of  irritans  "are  deposited  in  out-of-the-way  places, 
in  the  dust  or  lint  under  carpets,  and  the  larvae  are  said  to  feed  upon  the 
particles  of  organic  matter  which  may  be  found  in  such  localities."  Raillet 
states  that  each  female  deposits  eight  to  twelve  eggs  from  which  larvae  hatch, 
in  summer,  in  from  four  to  six  days,  become  pupae  eleven  days  later,  and 
after  about  twelve  days  in  this  stage  become  adult.  In  winter,  in  warmed 
houses,  the  whole  development  takes  about  six  weeks.  The  cat-  and  dog- 
flea  lays  its  eggs  on  or  among  the  hairs  of  an  infested  animal,  but  the 
eggs  drop  to  the  floor  or  ground  as  the  animal  moves  about,  and  the  larvae 
live  in  the  dust,  feeding  on  whatever  bits  of  organic  substance  they  can  find 
there.  Larvae  placed  on  dust  with  birds'  feathers  mixed  with  dried  blood 
developed  perfectly.  Others  put  on  the  sweepings  of  a  room  developed 
as  well.  These  fleas  are  especially  abundant  and  troublesome  in  houses 
in  the  East  in  damp  summers.  As  flea-larvae  will  not  develop  successfully 
in  places  where  they  are  often  disturbed,  much  sweeping  and  scrubbing 


The  Two- winged  Flies  357 

will  keep  them  down.  Mats  and  places  where  dogs  and  cats  He  down  should 
be  kept  well  dusted  with  pyrethrum.  (Buhach  is  the  trade  name  for  this 
insecticide,  which  is  not  injurious  to  man  or  domestic  animals.)  Where 
fleas  get  a  foothold  in  a  neglected  room  or  cellar,  the  remedy  used  by  Profes- 
sor Gage  in  the  basement  of  one  of  Cornell  University's  buildings  might  be 
tried;  i.e.,  tying  sheets  of  sticky  fly-paper,  sticky  side  out,  around  the  legs 
from  foot  to  knee  of  the  janitor  or  a  cheap  boy  and  having  him  tramp  for 
several  hours  around  in  the  room! 

Of  the  various  other  flea  species,  the  only  ones  that  come  into  special 
relation  with  man  are  the  rat-fleas.  The  proof  that  rats  are  active  agents 
in  the  dissemination  of  the  dreadful  bubonic  plague,  and  the  behef  of  some 
pathologists  that  the  disease-germs  may  be  transmitted  from  rats  to  man 
by  the  bites  or  punctures  of  rat-fleas,  gives  this  insect  a  special  interest  like 
that  attaching  to  the  malaria-  and  yellow-fever-dissminating  mosquito  and 
the  germ-carrying  house-fly.  Baker  pertinently  calls  attention  to  the  fact 
that  the  rat-fleas  of  this  country  are  only  remotely  related  to  Pulex  irritans 
and  Ctenocephalus  canis,  the  two  species  that  bite  human  beings,  while  the 
fleas  that  infest  rats  in  the  tropics  are,  on  the  contrary,  very  nearly  related  to 
the  man-infesting  kinds.  The  prevalence  of  the  bubonic  plague  in  tropical 
countries  and  its  rarity  with  us  may  be  connected  with  this  difference  in  the 
rat-flea  kinds. 


CHAPTER    XIV 

THE  MOTHS  AND  BUTTERFLIES  (Order  Lepidoptera) 

OTHS  and  butterflies  are  the  insects  most 
favored  of  collectors  and  nature  lovers;  a 
German  amateur  would  call  them  the  "Lieb- 
lings-insekten."  The  beautiful  color  patterns, 
the  graceful  flight  and  dainty  flower-haunting  habits,  and  the  interesting 
metamorphosis  in  their  life-history  make  them  very  attractive,  while  the  com- 
parative ease  with  which  the  various  species  may  be  determined,  and  the 
large  number  of  popular  as  well  as  more  technical  accounts  of  their  life 
which  are  accessible  for  information,  render  the  moths  and  butterflies  most 
available,  among  all  the  insects,  for  systematic  collecting  and  study  by 
amateurs. 

Despite  the  large  number  of  species  in  the  order  (6622  are  recorded  in 
the  latest  catalogue  of  the  North  American  forms)  and  the  great  variety  in 
size  and  pattern,  the  order  is  an  unusually  homogeneous  one,  even  a  begin- 
ning student  rarely  mistaking  a  moth  for  an  insect  of  any  other  order,  or 
classifying  a  non-lepidopterous  insect  in  this  order.  A  few  aberrant  species 
are  wingless  (females  only)  and  a  few  (certain  "clear-winged"  species)  have 
a  superficial  likeness  to  wasps  and  bumblebees,  but  the  general  habitus  of 
any  Lepidopteron,  let  alone  the  readily  determinable  and  absolutely  diag- 
nostic character  of  the  scale-covering  on  the  wings,  usually  indicates  unmis- 
takably the  afluiities  of  any  moth  or  butterfly. 

The  diagnostic  structural  characters  are  the  (already  mentioned)  pres- 
ence on  upper  and  lower  sides  of  both  wings  (as  well  as  over  the  surface  of 
the  body)  of  a  covering  of  small  sy-mmetrically  formed  scales,  which  are 
modified  hairs,  and  to  which  all  of  the  color  and  pattern  of  the  insects  are 
due.  In  Chapter  XVII  will  be  found  a  detailed  account  of  these  scales, 
e.xplaining  their  structure,  their  origin,  and  how  they  produce  the  color  pat- 
terns. The  wings  themselves  are  almost  always  present  (in  two  pairs),  the 
fore  wings  larger  than  the  hind  wings,  and  with  a  characteristic  venation, 
in  which  the  modifications,  though  small,  are  yet  so  constant  and  definite 
that  they  are  used  successfully  as  the  principal  basis  for  the  classification 
of  the  order  into  famihes.  Another  characteristic  is  the  highly  modified 
and  peculiar  condition  of  the  mouth-parts.  While  in  some  species  the  mouth- 
parts  are  rudimentary  (atrophied)  and  evidently  not  functional,  in  most 
there  is  a  well-developed  slender  flexible  sucking  proboscis  (Fig.  509)  com- 

358 


PLATE   V. 

BUTTERFLIES. 

i  =  Junonia  coenia. 
2=Iphidides  ajax. 
3=Epargyieus  tilyrus. 
4=  Cyan  iris  pseudargiolus. 
5  =  Ancy loxypha  n umitor. 
6=Papilio  turnus. 
7  =  Nathalie  iole. 
8=Parnassiu3  smintheus. 
9=Tlieda  halesus. 
io=  Zerene  ctesonia 


PLATE   V 


Mary  IVellman,  del. 


The  Moths  and  Buttertiies 


359 


posed  of  the  two  greatly  elongate  maxillae,  so  apposed  that  a  groove  on  the 
inner  face  of  one  fits  against  a  similar  groove  on  the  inner  face  of  the  other, 
the  two  thus  forming  a  perfect  tube  (Fig.  510).  This  sucking  proboscis,  when 
extended,  may  protrude  five  or  six 
inches,  as  in  some  of  the  sphinx- 
moths,  or  only  a  fraction  of  an  inch, 
as  in  the  small  moth  "millers,"  but 
when  not  in  use  it  is  so  compactly 
coiled  up,  watchspring-like,  under 
the  head,  and  so  concealed  by  a 
pair  of  hairy  little  tippets  (the  labial 
palpi)  which  project  up  on  each 
side  of  it  that  it  is  nearly  invisible. 
Of  the  other  mouth  -  parts,  the 
upper  lip  (labrum)  and  under  hp 
(labium)  are  greatly  reduced  and 
are  not  movable  and  flap-like  as  in 
most  insects,  while  the  mandibles 
are  either  wholly  wanting  or,  as  in 
the  sphinx-moths  and  some  others, 
represented  only  by  small  immov- 
able functionless  rudiments.  The 
palpi  of  the  maxillae  are  also  either 
wholly  wanting  or  present  as  mere 
rudiments.  The  foregoing  descrip- 
tion of  the  mouth-part  conditions 
is  true  for  the  great  majority  of 
Lepidoptera,  but  among  the  lowest 
(oldest  or  most  generalized)  moths 
some  interesting  examples  of  much 
less  specialized  conditions  occur. 
Indeed  in  one  family  of  minute 
moths,  the  Eriocephalidas,  all  the 
usual  parts  of  a  typical  insect 
mouth  are  present  and  in  a  condi- 
tion fitted  for  biting  and  chewing 
and  in  all  ways  wholly  comparable 
with  the  condition  in  such  biting 
mandibles    are    movable 


Fig.  507. — A  trio  of  apple  tent -caterpillars, 
larvas  of  the  moth  Clisiocampa  americana. 
These  caterpillars  make  the  large  unsightly 
webs  or  tents  in  apple-trees,  a  colony  of 
the  caterpillars  living  in  each  tent.  (Photo- 
graph from  life  by  Slingerland;  natural  size.) 


insects  as  the  locusts  and  beetles;  the 
and  truly  jaw-like,  the  maxillas  short  and  rlso 
jaw-like  and  provided  with  several-segmented  palpi,  while  both  labrum 
and  labium  are  truly  lip-  or  flap-like  and  fully  movable,  the  labium 
bearing    3-segmented    palpi.     Between    this    most    generalized    condition 


360 


The  Moths  and  Butterflies 


^ 


Fig.  508. — Bit  of  wing  of  monarch  but- 
terfly, Anosia  plexippiis,  showing  scales; 
some  scales  removed  to  show  the  inser- 
tion-pits and  their  regular  arrangement. 
(Greatly  magnified.) 

stage.     The    immature    staees   of 


and  the  extreme  speciaUzation  of  the  butterfly's  mouth  an  interesting  and 
illuminating  gradatory  series  is  dis- 
coverable by  examining  moths  of  suc- 
cessively more  specialized  character. 
The  development  of  moths  and 
butterflies  shows  the  usual  character- 
istics of  devel- 
opment with 
complete  meta- 
morphosis, the 
larval  or  cater- 
pillar stage  be- 
ing quite  dis- 
similar from 
the  pupal  or 
chrysalid  stage, 
and  that  in 
turn  from    the 

adult   or   imaginal    stage.     'I'he    immature    stages 
Lepidoptera  are  more  familiar  than  those  of  any  other 
order;  we  have  all  seen,  and  recognized  for  what  they 
are,  the  caterpillars  and  chrysalids  of  various  moths 
and  butterflies.     The   great   silken   cocoons  found   on 
orchard-trees  in  winter-time    are    known    to    contain 
the    pupae   of     giant    moths,    as    the 
Cecropia,  the  Polyphemus,  and  others, 
while    the  soft-bodied  green  tomato- 
worms  are  as  well  known  to  be  the 
young    (larvae)    of   the    hawk-moths. 
As  a  matter  of  fact  the  young  stages 
of  no  other  of  the  insects  with  com- 
plete   metamorphosis    are  so   nearly 
unmistakably  characterized  by  their 
common  possession  of    certain  well- 
defined  features.     The  larvae  or  cater- 
pillars, for    example,  with   very   few 
exceptions,   possess,   in    addition    to 
three  pairs  of  jointed  legs  on  the  first 
three     segments    behind    the     head, 
from    three     to    five    pairs    of   short 
fleshy  unjointed    legs   or  feet  called 
prop-legs,  on  certain  abdominal  seg- 


FiG.  509. — Sucking-proboscis  of  a  sphinx- 
moth;  at  left  the  proboscis  is  shown 
coiled  up  on  the  under  side  of  the  head, 
the  normal  position  when  not  in  use. 
(Small  figure,  natural  size;  large  figure, 
one-half  natural  size.) 


The  Moths  and  Butterflies 


3 


6i 


ments;  one  of  these  pairs  is  on  the  last  segment  and  four,  which  is  the  num- 
ber present  in  all  except  the  inchworms  or  loopers  (larvae  of  the  Geometric! 
moths),  are  on  the  sixth,  seventh,  eighth,  and  ninth  segments  behind  the 
head.  The  inchworms  have  prop-legs  only  (with  a  few  exceptions)  on  the 
ninth  and  last  segments.  These 
prop-legs,  together  with  the  striped 
or  hairy  body- surface,  make  a 
moth  or  butterfly  larva  almost  as 
readily  recognizable  for  what  it  is 
as    the    scale-covered   wings   make 


Fig.  510.  Fig.  511.  Fig.  512. 

Fig.  510. — Cross-section  of  sucking-proboscis  of  milkweed-butterfly,  Anosia  plexippus; 

see  tubular  cavity,  c,  formed  by  apposition  of  the  two  maxillae,   tr.,  trachea;  n.,  nerve; 

m.,   muscles.     (After  Burgess;    greatly  magnified.) 
Fig.  511. — Bit  of  maxillary  proboscis  of  milkweed-butterfly,  Anosia  plexippus,  showing 

arrangement  of  muscles  in  the  interior;    these  muscles  serve  to  coil  up  or  to  extend 

the   proboscis;   see   groove   on  inner  face   of  maxilla.    in.,   muscles;    tr.,  trachea; 

71.,  nerve;  c,  groove. 
Fig.  512. — Diagram  of  arrangement  of   pharynx,  oesophagus,  etc.,  in  interior  of  head 

of   monarch    butterfly,  Anosia  plexippus,  showing  means  of  producing  suction  in 

the  proboscis,    oe.,  oesophagus;  t?»?.,  dorsal  muscle;  /.w.,  frontal  muscle;  c/.,  clypeus; 

hyp.,  hypopharynx;    s.d.,  salivary  duct;    ep.,  epipharynx;    mx.,  maxilla. 

the  adult  moth  or  butterfly  distinguishable  from  any  other  kind  of  insect. 
The  chrysalids  with  their  hard  shell,  but  with  the  folded  antenuce,  legs,  and 
wings  of  the  enclosed  developing  adult  always  indicated,  are  also  hardly  to 
be  mistaken  for  the  pupae  of  any  other  orders,  while  even  the  eggs,  when  ex- 
amined under  a  magnifier,  mostly  reveal  their  lepidopterous  parentage  by 
the  beautiful  fine  sculpturing  of  the  shell  (Fig.  67).  As  will  be  noted 
from  a  perusal  of  the  accounts  of  the  life-history  of  various  familiar  and 
representative  moths  and  butterflies  given  in  the  following  pages,  there  is 
much  variety  in  the  means  shown  of  protecting  the  defenceless  pupae;  some 
are  subterranean,  the  leaf-feeding  larvae  crawling  down  from  tree-top  or 
weed-stem  and  burrowing  into  the  ground  before  pupation;  others  are 
enclosed  in  a  tough  silken  cocoon  spun  by  the  larva  before  making  its 
last  moult;  while  those  which  are  not  protected  in  one  or  the  other  of  these 
ways  either  lie  in  concealed  spots  under  stones  or  in  cracks  of  the  bark, 
etc.,  or  are  so  colored  and  patterned  that  they  blend  indistinguishably  with 
the  object    against  which    they  are  suspended.     The  larvae  have  also  their 


362 


The  Moths  and  Butterflies 


various  means  of  defence;  the  hairy  ones  are  an  uncomfortable  mouthful 
for  a  bird,  the  naked  and  brighdy  marked  ones  usually  contain  an  acrid 
and  distasteful  body  fluid,  while  still  others  find  protection  in  a  color  pattern 
harmonizing  with  their  habitual  environment. 

The  food-habits  of  the  larvae  make  of  many  of  them  serious  pests  of 
our  growing  crops.  Most  are  leaf-eaters  and  all  are  voracious  feeders,  so 
that  an  abundance  of  cutworms  or  army- worms  or  maple-worms  or  tomato- 
worms  always  means  hard  times  for  their  favorite  food-plants,  which  are 
too  often  growing  grain  and 
vegetables,  and  leafing  or- 
chard and  foliage  trees.  f  (  /f  )  niAii)])^-"'"'^'^' 
Others  attack  fruits,  as  that  (  ^^f\"^^'  /  y/%r^'^^ 
dire  apple  pest,  the  codlin- 
moth  larva ;  while  still  others             '"  p^-   '""''^                      /ff\y\f)\'  ^P- 


Fig.  513. 


Fig.  514. 


Fig.  513. — Front  of  head,  with  scales  removed,  of  sphinx-moth,  showing  frontal  sclerites 
and  mouth-parts,  f/^.,  epicranium;  5!(.,  suture;  c/.,  clypeus;  ^e.,  gena  or  cheek; />/., 
piUfer  of  labrum;  md.,  mandible.  Between  the  two  pilifers  the  base  of  the  sucking- 
proboscis  composed  of  the  apposed  maxillae  is  seen.     (Much  enlarged.) 

Fig.  514. — -Diagram  showing  mouth-parts  of  Lepidoptera.  Figure  in  upper  left-hand 
corner,  head,  with  scales  removed,  of  Catocala  sp.:  cl.,  clypeus;  ge.,  gena  or  cheek; 
mx.p.,  maxillary  palpus;  pj.,  pilifer  of  labrum.  In  upper  right-hand  corner,  ventral 
aspect  of  head  of  Catocala  sp.:  mx.p.,  maxillary  palpus;  ge.,  gena  or  cheek;  mx.b., 
base  of  maxilla;  gu.,  gula;  Im.,  labium;  Ip.,  basal  segment  of  labial  palpus.  In 
lower  left-hand  corner,  frontal  aspect  of  head,  with  scales  removed,  of  sphinx- 
moth,  Protoparce  Carolina:  ep.,  epicranium;  cl.,  clypeus;  lb.,  labrum;  pj.,  pilifer 
of  labrum;  md.,  mandible;  ge.,  gena  or  cheek.  In  lower  right-hand  corner,  ffont 
of  head,  with  scales  removed,  of  monarch  butterfly,  Anosia  plexippus  lb.,  labrum; 
g.,  gena  or  cheek;    pj.,  piUfer  of  labrum.     (Much  enlarged.) 

are  content  with  dry  organic  substances,  as  the  larvae  of  clothes-moths,  meal- 
moths,  and  the  like.  For  all  of  this  kind  of  feeding  very  different  mouth- 
parts  are  needed  from  the  delicate  sucking-proboscis  characteristic  of  the 
adults,  and  the  lepidopterous  larvae  are  all  provided  with  well-formed  jaw-like 
mandibles  and  other  parts  going  to  make  up  a  biting  mouth  structure.  The 
larval  eyes  are  simple  ones,  not  compound  as  in  the  adults;  the  antennae 
are  short  and  inconspicuous,  not  large  and  feathered  as  in  the  moths,  or 
long  and  thread-like,  with  knobbed  tip,  as  in  the  butterflies.     Altogether  the 


The  Moths  and  Butterflies 


363 


lepidopterous  larva  is  a  well-contrived  animal  for  its  especial  kind  of  life, 
which  is  as  different  as  may  be,  almost,  from  that  which  it  will  lead  after 
it  has  completed  its  metamorphosis.  Always  when  one  reads  or  hears  of 
injurious  moths  or  butterflies  it  should  be  kept  clearly  in  mind  that  the 
injuries,  to  crops  or  fruit  or  woolen  clothing  or  what  not,  are  caused  by  the 
moth  or  butterfly  in  its  larval 


stage  and  never  by  the  flut- 
tering nectar-sipping  adult. 
The  sole  compensation, 
other  than  the  rather  imma- 
terial though  perhaps  not 
less  real  one  afforded  us 
through  our  jesthetic  ap- 
preciation of  the  beauty 
and  attractive,  apparently 
care-free,  flitting   about  of 


ant 


Fig.  517. 


Fig.  518. 


Fig. 


Fig. 


515. — Front  of  head  of  larva  of  tussock-moth,  Notolophus  leucostigma.  ant.,  antenna; 

md.,  mandible;  vjx.,  ma.xilla;  mx.p.,  maxillary  palpus;  li.,  labium.    (Much  enlarged.) 
516. — Front  of   head  of  old  larva  of  tussock-moth,  Notolophus  leucostigma,    with 

head-wall  dissected  away  on   right-hand  side  to  show  forming  adult  mouth-parts 

underneath,      l.ant.,  larval  antenna;     ant.,  adult  antenna;    l.md  ,  larval  mandible; 

l.mx.,  larval  ma.xilla;  i.nix.,  adult  maxilla;    lb.,  larval   labrum;  /./i,  larval  labium. 

(Much  enlarged.) 
Fig.  517- — Developing  adult  head  dissected  out  from  head  of  larva  of  tussock-moth, 

Notolophus  leucostigma.    ant.,  antenna;   mx.,  maxilla;    li.p.,  labial  palpus.     (Much 

enlarged.) 
Fig.  51S. — Head  of  tussock-moth,  Notolopliw;  leucostigma;   showing  adult  antenna;  and 

mouth-parts,    mx.,  maxilla;    li.p.,  labial  palpus.     Note  that  the  two  maxilla;  are 

not  locked  together  to  form  a  sucking-proboscis,  the  mouth-parts  of  this  moth  being 

rudimentary  and  not  capable  of  taking  food.     (Much  enlarged.) 

the  butterfly,  which  the  Lepidoptera  make  for  their  often  disastrous  toll  on 
our  green  things,  is  the  prodigal  gift  of  silk  made  by  the  moth  species  known 
as  the  mulberry  or  Chinese  silkworm.  Thoroughly  domesticated  (the  wild 
silkworm  species  is  now  not  even  known),  this  industrious  spinner  produces 
each  year  over  one  hundred  million  of  dollars'  worth  of  fine  silken  thread 


3^4 


The  Moths  and  Butterflies 


ready  for  the  loom.  In  Italy  and  Japan  nearly  every  country  household  has 
its  silk-rooms  in  which  thousands  of  the  white  "worms"  are  carefully  fed  and 
tended  by  the  women  and  children,  and  from  which  comes  enough  raw  silk 
to  furnish  a  good  share  of  the  annual  income  of  each  of  these  households. 

The  reader  who  would  undertake  the  collecting  of  moths  and  butterflies, 
or  the  rearing  of  caterpillars  in  home  "  crawleries,"  is  referred  for  some 
specific  directions  for  this  work  to  the  appendix  of  this  book,  p.  635  et  seq. 

The  order  Lepidoptera  may  be  most  conveniently  divided  into  two  prin- 
cipal subgroups  (suborders  they  are  often  called),  namely,  the  Heterocera, 


Fig.  519. — Larva  of  obsolete-banded  strawberry  leaf-roller,  Cacoecia  obsoletana.  (Photo- 
graph from  life  by  SUngerland;  natural  size  in  lower  corner  and  twice  natural  size 
above.) 

or  moths,  and  the  Rhopalocera,  or  butterflies.     All  butterflies  have  antennae 

which  are  slender  (filiform)  for  most  of  their  length,  but  have  the  tip  expanded 

or  thickened,  forming  an  elongate  spindle-shaped  dilation  or  "club";  the 

moths  have  their  antennae  variously  formed,  as  wholly  filiform,  pectinate, 


The  Moths  and  Butterflies 


365 


Fig.  520. — Pupa  of  obsolete-banded  strawberry  leaf-roller,  Cacoccia  ohsoletana.     (Photo- 
graph from  life  by  Slingerland;    natural  size  a  little  more  than  one-half  inch.) 


Fig.    521. — Moths   of   the   obsolete-banded    strawberry   leaf-roller,   Cacoecia   obsoletaiia, 
male  above,  female  below.     (Photogt^aph  from   life  by  Slingerland;    natural  size.) 


366 


The  Moths  and  Butterflies 


The  Moths  and  Butterflies 


367 


etc.,  but  never  showing  the  characteristic  swollen-tipped  or  clubbed  con- 
dition of  the  butterflies.  The  moths,  too,  are  mostly  night  or  twilight  flyers, 
while  the  butterflies  go  abroad  in  sunlight  only.  Scientific  students  of  Lepi- 
doptera  do  not  give  the  butterflies  a  classific  value  equivalent  to  that  of  the 
moths  taken  altogether,  but  rather  rank  them  as  a  group  more  nearly  equiva- 
lent to  a  single  superfamily  of  moths,  as,  for  example,  the  superfamily  Satur- 
niina,  which  includes  all  our  great  silkworm-moths,  Cecropia,  Luna,  Prome- 
thea,  Polyphemus,  etc.,  etc.  However,  the  more  familiar  and  readily  made 
subdivision  of  the  order  into  moths  and  butterflies  is  more  convenient  and 


Fig.  523. — ISIoth  and  cocoon  cut  open  to  show  pupa  of  Samia  cecropia.     (After  Lugger; 

slightly  reduced.) 

quite  as  informing  for  our  purpose,  so  we  shall  adopt  it,  taking  up  the  moths 
first,  as  including  the  more  generalized  members  of  the  order.  There  are  many 
more  moth  than  butterfly  families,  the  numbers  represented  in  this  country  being 
44  to  5.  By  reference  to  the  following  key  adapted  from  Comstock  aln  ost  any 
North  American  moth  can  be  traced  to  its  proper  family. 

KEY  TO  THE  SUPERFAMILIES  AND   FAMILIES   OF  MOTHS. 
This  key  does  not  include  a  few  of  the  smaller  families  whose  members  are  very  few 
and  are  rarely  taken  by  collectors.     Some  of  these  moths  are,  however,  referred  to  in 


368  The  Moths  and  Butterflies 

the  systematic  account  of  the  families  which  follows  later.  To  use  the  key  requires 
an  acquaintanceship  with  the  plan  of  venation  in  the  wings  and  the  nomenclature  of 
the  veins.  This  may  be  got  from  an  inspection  of  Fig.  525,  and  by  referring  to  the 
various  other  figures  illustrating  the  typical  venation  for  the  various  important  families. 
To  see  clearly  the  veins,  a  necessary  prerequisite  to  using  the  key,  a  few  drops  of  ether 
should  be  put  on  the  outstretched  wing  of  a  spread  specimen  and  this  held  so  that  bright 
light,  as  from  a  window  or  lamp,  may  pass  through  the  wing  to  the  eye.  For  a  few 
moments  (until  the  evaporation  of  the  ether)  the  covering-scales  will  be  transparent 
and  the  number  and  course  of  the  veins  plainly  visible.  The  ether  will  not  injure  the 
specimen  at  all.  If  duplicate  specimens  are  available,  the  fore  and  hind  wings  of  one 
side  may  be  removed  and  placed  in  a  watch-glass  or  small  saucer  containing  Eau  de 
Labarraque  (to  be  obtained  of  a  druggist),  when  the  scales  will  be  bleached  perfectly 
transparent.  The  wings  may  be  then  washed  and  mounted  on  glass  sHdes  with  glycerine 
jelly  and  thus  be  made  available  for  inspection  at  any  time. 

A.  Moths  which  have  a  thin  lobe-Hke  process  (jugum)  projecting  backward  from  the 
base  of  the  fore  wing,  which  holds  fore  and  hind  wings  together  when  they  are 
outstretched;    veins  similar  in  number  and  arrangement  in  both  wings  (Fig.  526). 

(The  Jugatse.) 
B.      Very   small   moths,    not   more   than   one-fifth   inch   long. 

MiCROPTERYGiD^  and  Eriocephalid.e. 

BB.  Moths  from  one-half  to  one  inch  long (The  Swifts.)     Hepialid^. 

AA.  Moths  whose  wings  are  not  united  by  a  jugum  but  by  a  frenulum  (Fig.  533),  and 
in  which  the  veins  in  the  hind  wing  are  less  in  number  than  in  the  fore  wing. 

(The  Frenatse.) 
B.      Hind  wings  with  fringe  on  hinder  margin  as  long  as  the  width  of  the  wing; 

hind  wings  often   lanceolate  in   shape Superfamily  Tineina  (part). 

BB.  Hind  wings  with  narrow  or  no  fringe,  and  not  lanceolate  in  shape. 

C.      Wings   fissured,   i.e.,    divided   longitudinally  into   several   narrow   parts. 
(Plume-moths.)     Pterophorid^  and  ORXEODiD.i;. 
CC.  Wings  not  fissured. 

D.      Fore  wings  very  narrow;    part  of  the  hind  wings  always,  and  of 
the   fore   wings   often,   clear,   i.e.,   without  scales. 

(Clear-winged  moths.)     Sesiid.^. 
DD.  Wings  all  covered  with  scales  or,  if  partly  clear,  the  fore  wings  broad. 
E.      Hind  wings  with  three  anal  veins. 

F.      Subcosta  and  radius  of  hind  wings  close  together  or  fused 
beyond  the   discal  cell   (Fig.   533). 

Superfamily  Pyralidina. 
FF.   Subcosta  and  radius  of  hind  wings  widely  apart  beyond 
the  discal  cell. 

G.  Small;  palpi  usually  prominently  projecting;  fringe  on 
inner  angle  of  hind  wings  longer  than  on  rest  of  margin. 
H.      Second  anal  vein  of  hind  wings  forked  at  the 

base  (Fig.  539) Superfamily  Tortricina. 

HH.  Second   anal   vein   of   hind   wings   not   forked 

at  base Superfamily  Tineina  (part). 

GG.  Medium  or  large;  palpi  not  conspicuously  project- 
ing beyond  the  head  and  fringe  on  inner  angle  of 
hind  wings  only  slightly  or  not  at  all  longer  than 
on   rest  of  margin. 


The  Moths  and  Butterflies  369 

H.      Subcosta  and  radius  of  hind  wings  fused  nearly 
to  end  of  the  discal  cell  (Fig.  553). 

I.  Small    black    moths. 

(Smoky-moths.)     Pyromorphid^  (part). 

II.  With  long,  curling,  light-colored  or  brown 
woolly  hairs 

(Flannel-moths.)     Megalopygid.e. 
HH.  Subcosta   and   radius   of    hind   wings   distinct 
or  only  slightly  fused. 

I.  Anal  veins  of  fore  wings  anastomosing  so 
as  to  appear  as  a  branched  vein  (Fig.  552). 

(Bag-worm  moths.)     Psychid.^. 

II.  Anal  veins  not  anastomosing. 

J.  Vein  m^  of  fore  wings  arising  from  the 
discal  cell  nearly  midway  between 
veins  Wj  and  m^  (Fig.  603). 

(Silkworm-moths.)     Bombycid^. 

JJ.  Vein  m^  of  fore  wings  rising  from  discal 

cell  nearer  to  cubitus  than   to  radius, 

so  that  cubitus  appears  four-branched 

(Fig.  548). 

(Carpenter-moths.)     CossiD^. 
EE.  Hind  wings  with  less  than  three  anal  veins. 

F.  Fore  wings  with  two  distinct  anal  veins  or  with  these  two 
veins  partly  fused  so  as  to  appear  like  a  single  branched  vein. 
G.      The  two  anal  veins  distinct  (Fig.  553). 

Pyromorphid.e  (part). 

GG.  The  two  anal  veins  partly  fused  and  appearing  like 

a  single  branched  vein  (Fig.  552).    PsYCHiDiE  (part). 

FF.  Fore  wings  with  but  one  complete  anal  vein  (rudiments  of 

one  or  two  others  sometimes  present). 

G.      Frenulum  present. 

H.  Hind  wings  with  subcosta  and  radius 
apparently  distinct,  but  connected  by  a  strong 
oblique  cross-vein;  moths  mostly  with  narrow, 
long,  strong  front  wings  and  small  hind  vwngs. 
(Sphinx-  or  hawk-moths.)  Sphingid^. 
HH.  Hind  ^vings  with  subcosta  and  radius  either 
distinct  or  fused,  but  not  connected  by  an 
oblique  cross-vein. 

I.  Vein  m..^  of  fore  wings  closer  to  radius  than 
cubitus,  cubitus  being  apparently  three- 
branched. 

J.  Subcosta  of  hind  wings  extending 
from  base  to  apex  of  wing  in  a  regular 
curve  (Fig.  560);  moths  with  heavy 
abdomen  and  rather  narrow  strong 
fore  wings. 

(The  prominents.)     Notodontid.^. 

JJ.  Subcosta  of  hind  wings  with  its  basal 

part  making  a  prominent  bend  into  the 


370  The  Moths  and  Butterflies 


humeral  angle  of  the  wing  (Fig.  567); 

moths   mostly    with   slender   abdomen 

and  rather  broad  dehcate  fore  wings. 

Superfamily  Geometrina. 

II.     Vein  Wj  of  fore  wings  more  closely  joined 

to  cubitus  than  to  radius,  so  that  cubitus 

is    apparently    four-branched. 

J.     Subcosta  of  hind  wings  distinct  from 

radius,  or   the    two    fused    for   a    very 

short    distance    near   the    base    of   the 

wing  (Fig.  584). 

K.  Day-flying  moths  that  are  black 
with  large  white  or  yellow  patches 
on  the  wings,  or  with  white  front 
wings  margined  with  brown,  and 
having  the  hind  wings  pale  yellow. 
(Wood-nymph  moths.)  Agaristid^  and  Pericopid.e. 
KK.  Not   such   moths. 

L.      Ocelli  absent;   antennae  pec- 
tinate. 
(Tussock-moths.)     Lymantriid^. 
LL.  Ocelli  present  or,  if  absent, 
with  simple  antennae. 
(Owlet-moths.)     Noctuid.e. 
JJ.  Subcosta  of  the  hind  wings  fused  with 
radius    for    one-fifth    or   more    of    the 
length  of  the  discal  cell. 
K.      Subcosta  and  radius  of  hind  wings 
fused  entirely  or  vnth  only  the  tips 
separate  (Fig.  591). .  .Zyg^nid.e 
KK.  Subcosta  and  radius  of  hind  wings 
united   for   about   one-half   their 
length,     of    more,     but     usually 
separating  before  the  apex  of  the 
discal  cell  (Fig.  597). 
L.      Ocelli    present. 

(Tiger-moths.)     Arctiid^e. 

LL.  OceUi    absent. 

(Footman-moths.)     Lithosiid.e. 

GGo  Frenulum   absent;    the  humeral  angle  of  the  hind 

wings  largely  expanded  and  serving  as  a  substitute 

for  the  frenulum  (Fig.  600). 

H.  Cubitus  of  both  wings  apparently  four-branched 
(Fig.  600).     (Tent-caterpillar  moths  et  al.) 

LASICOCAMPID.E. 
HH.  Cubitus     of    both     wings     apparently     three- 
branched;  robust  moths  with  broad  wings  (Fig. 
603).       (Giant  silkworm-moths.)  Saturniina. 


The   jugate  moths   include   but   two   families,  the  Micropterygida^   and 
Hepialidae,  both  represented  by  but  few  species  and  these  rarely  met  with 


The  Moths  and  Butterflies 


371 


by  collectors  and  nature  students.  But  these  moths  are  of  particular  impor- 
tance and  interest  to  entomologists  because  they  are  undoubtedly  the  oldest 
or  most  generalized  of  living  Lepidoptera;  they  represent  most  nearly,  among 
present-day  existing  moths,  the  ancestral  moth  type.  This  is  shown  most 
conspicuously  by  the  similarity  in  size,  shape,  and  venation  of  the  fore  and 
hind  wings,  for  the  primitive  winged  insects  had  their  two  pairs  of  wings 
equal,  while  nowadays  the  various  orders  show  a  marked  tendency  to 
throw  the  flight  function  on  one  pair,  either  the  fore  wings,  as  among  the 
flies  (Diptera),  wasps,  bees,  etc.  (Hymenoptera),  and  Lepidoptera,  or  the 
hind  wings,  as  with  the  locusts,  crickets,  etc.  (Orthoptera),  and  beetles  (Cple- 
optera),  the  other  pair  becoming  much 
reduced  in  size,  or  even,  as  in  the 
Diptera,  wholly  lost.  Quite  as  impor- 
tant, if  not  more,  although  not  so  con- 
spicuous, as  an  evidence  of  the  ancient 
character  of  the  jugate  moths,  is  the 
condition  of  the  mouth-parts,  certain 
species  in  the  group  having  true  biting 
mouth-parts,  with  well  developed  man- 
dibles, short  lobe-like  maxillae,  and  short, 
truly  hp-like  labium.  All  other  moths 
and  butterflies  have  the  mouth-parts 
specialized  for  sucking,  with  the  man- 
dibles rudimentary  or  wanting,  the  max- 
illje  produced  and  apposed  to  form  the 
long  flexible  sucking-tube,  and  the  under 
lip  (labium)  reduced  to  a  mere  immovable 
functionless  sclerite.  The  presence  of 
the  jugum  for  tying  the  fore  and  hind 
wings  together,  as  in  the  caddis-flies.  Fig.  524. — Diagram  showing  venation 
undoubtedly  nearly  alhed  to  the  moth  of  wings  in  monarch  butterfly,  ^^mm 
■'  ■'  plexippus.     c,  costal  vein;   sc,   sub- 

ancestors,     instead      of      the     specialized       costal  vein;   r.,  radial  vein;   cm.,  cubi 

frenulum  as  in  other  moths,  is  also  evi- 
dence of  the  ancestral  type  displayed  by 
the  Jugatae. 

The  Micropterygidae,  represented  in 
this  country  by  two  genera,  Eriocephala, 
with  four  species,  and  Epimartyria  (Micropteryx) ,  with  two  species,  are  among 
the  smallest  moths  we  have,  the  largest  not  expanding  more  than  one-third 
of  an  inch  and  the  smallest  only  one-fifth  of  an  inch,  the  body  being  about 
one-tenth  of  an  inch  long.  They  are  indeed  almost .  invisible  when  flying, 
and   are   only  very  rarely  taken   by  collectors.      They  fly  in  the    sunshine, 


tal  vein;  a.,  anal  veins.  The  base  of 
the  medial  vein  (lying  between  radius 
and  cubitus)  is  obsolete,  but  its 
branches  still  persist,  lying  between 
branches  of  radius  and  cubitus. 
(Natural  size.) 


372 


The  Moths  and  Butterflies 


frequenting  flowers,  and  the  different  species  are  so  much  alike  as  to  be 
nearly  indistinguishable  to  the  amateur.  The  eggs  are  laid  on  leaves,  or  in 
tiny  pits  in  them,  and  the  minute  larvae,  short  and  oblong,  are  either  foot- 
less and  mine  the  leaf  substance,  or  have  eight  pairs  of  abdominal  legs  and 
feed  exposed  on  leaves  or  in  moss.  The  leaf-mining  larvae  burrow  into  the 
ground  to  pupate,  while  the  exposed  feeders  make  a  slight  cocoon  of  silk  and 
debris  above  ground.  The  pupae  are  more  like  caddis-fly  pupaj  than  the 
usual  lepidopterous  chrysalids  (another  indication  of  the  primitive  char- 
acter of  the  family),  and  those  of  certain  species  have  large  mandibles  which 
they  use  to  cut  their  way  out  of  the  cocoon.  The  adults  can  best  be  dis- 
tinguished by  the  venation  of  the  wings  (Fig.  525),  and  if  ever  found  should 
be  highly  prized  by  the  collector  as  specimens  of  the  most  primitive  living 
Lepidoptera. 

The  Hepialidae,  the  ghosts  or  swifts,  although  an  offshoot  from  the 
Micropterygidae,  or  at  least  much  more  nearly  related  to  them  than  to 
any  other  moths,  are  very  different  in  appearance,  being  from  an  inch  to 
2k  inches  long  (some  foreign  species  have  a  wing  expanse  of  6  inches) 
with  large  broad-ended  wings  and  rather  heavy  body.  They  can  be  recog- 
nized by  their  venation  (Fig.  526),  which  distinguishes  them  from  all  other 
moths  of  their  size.     The  mouth-parts  are  rudimentary,  but  the  parts  per- 


sc    rjr3r3r4 

~m — r. — '<^^r~p^mJ 

a    a     ^'''  y 

Fig.  525.  Fig.  526. 

Fig.  525. — Diagram  of  wing  venation  of  Micropteryx  sp.  cs,  costal  vein;  sc,  subcostal 
vein;  r,  radial  vein;  m,  medial  vein;  c,  cubital  vein;  a,  anal  veins.  (After  Com- 
stock;    enlarged.) 

Fig.  526. — Diagram  of  wings  of  Hepialus  gracilis,  showing  jugum  (7),  and  similarity  of 
venation  in  fore  and  hind  wings.     (After  Comstock.) 


sisting  indicate  plainly  that  they  are  reduced  remnants  of  a  very  simple  set 
of  structures.  The  labium  is  free  and  truly  lip-like  and  of  the  type  of  the 
under  hp  of  biting  insects.  Two  genera,  Sthenopis,  four  species,  and  Hepi- 
alus, nine  species,  occur  in  this  country.    All  of  these  moths  are  rather  sombre 


The  Moths  and  Butterflies 


373 


in   color,  being   grayish,  yellowish  brown,  and   reddish  brown,  with  a  few 

silvery-whitish  irregular  streaks  on  the  upper 
wing  surface.  They  fly  swiftly  and  are  said  to 
prefer  twilight.  The  males  of  some  species  give 
off  a  strong  scent  to  attract  the  females.  Others 
seem  to  show  off  their  silvery  spots  by  hovering 
for  some  time  in  the  air  at  twilight,  being  con- 
spicuous, despite    the    semi-darkness  and   the 

^^^-  ^^"^ll^-^^n  '^'l"*«^s-moth,       -g^  p-eneral  coloration  of  the  moth,  by  a  pale 
I  inea  peUwnella;   larva,  larva   ^  o  j     .        r 

in  case,    and  adult.      (After  silvery  appearance.     Females  have  been  seen 
Howard  and  Marlatt;    twice  ^^  fly  directly  to   the   ghostly  hovering  males 

natural  size.)  ..  '  ,        _,,  .    i-.       , 

as  if  strongly  attracted.  Ihe  grub-like  larvae 
feed  in  the  roots  of  various  plants,  as  ferns  and  others,  or  in  the  trunk-wood 
of  various  shrubs  and  trees,  and  live  for  two  or  three  years.  Sthenopis 
argenteo-maadatus  feeds  first  in  the  roots  of  alder,  later  going  into  the 
stems.  It  either  pupates  in  its  burrow  or  in  a  loose  cocoon  in  the  soil. 
The  pupce  are  provided  with  certain  short  spiny  teeth,  and  can  wriggle  so 
strongly  that  they  are  able  to  move  about  in  the  burrows  or  soil,  and  when 
ready  to  transform  work  their  way  to  the  surface  of  the  ground. 

The  Jugat£e  are  looked  on  by  Comstock  as  equivalent  in  ranking  to  all 
the  other  moths  and  all  the  butterflies  combined  which  are  given  the  sub- 
ordinal  name  Frenatae.  That  is,  this  scant  dozen  of  persisting  represen- 
tatives of  the  ancient  moth  type,  or  rather 
of  immediate  offshoots  from  the  ancestral 
type,  are  to  be  distinguished  subordinally 
from  all  other  living  Lepidoptera,  however 
more  striking  may  appear  the  differences 
between  some  of  these,  as  the  obscure 
clothes-moths  and  the  regal  Cecropias,  or  the 
dull  moth-millers  and  the  brilliant  day-fly- 
ing butterflies.  The  Frenate  Lepidoptera 
include  all  those  forms  which  have  the  vena- 
tion of  the  hind  wings  reduced  (branches 
less  in  number  than  in  the  fore  wings) 
and  whose  wings  are  tied  together  by  a 
frenulum  (Fig.  533)  or  by  the  expanded 
humeral  angle  of  the  hind  wing  overlapping 
the  base  of  the '  fore  wing,  or  by  no  more 
elaborate  means  than  the  simple  overlapping 
of  front  margin  of  hind  wing  and  hind 
margin  of  fore  wing,  but  never  by  a  jugum, 
the  caddis-fly-like  method  common  to  the  Micropterygids  and  Hepialids. 


Fig.  528. — Larva  of  the  palmer- 
worm,  Ypsolopliiis  pomatellus, 
lying  under  its  web  spun  on  a 
leaf  (After  Lowe;  natural  length 
\  inch.) 


374 


The  Moths  and  Butterflies 


Among  the  Frenatae  there  is  a  host  of  small  obscure  moths  commonly 
lumped  by  collectors  and  amateurs  under  the  name  Microlepidoptera,  which 

are  little  known  because  httle 
studied,  but  which  professional 
entomologists  recognize  as  in- 
cluding all  together  eleven  moth 
families  grouped  into  three  dis- 
tinct superfamiHes.  Among  these 
microlepidoptera  are  probably  the 
most  generahzed  of  the  frenate 
Fig.  529.  Fig.  530.  moths. 

Fig.  529. — The  palmer-worm  moth,  Ypsolophiis  The  three  microlepidopteroUS 
P^-^^atellus.       (After    Fitch;     twice    natural  s^perfamilies     are     the    Tineina, 

Fig  530. — The  strawberry  root-borer>  Anarsia  including  the  clothes-moths,  leaf- 
Uneatella.  (After  Saunders;  moth  and  larva  miners,  and  Others,  the  Tortri- 
both  natural  size  and  enlarged.)  . 

cina,  including  most  of  the  leaf- 
rollers,  the  notorious  codlin-moth  and  others,  and  the  Pyralidina,  including 
certain  leaf-rollers  and  folders,  the  close-wings,  the  curious  plume-moths,  the 
injurious  meal-moths,  and  the  bee-moth,  principal  pest  of  the  bee-keeper. 

The  Tmeidae,  only  family  of  the  Tineina,  are  best  known  by  their  house- 
hold representatives,  the  clothes-moths.  Of  these  there  are  several  species, 
the  moths  themselves  looking  much  alike,  although  distinguished  by  some 
differences  in  marking,  but  the  larvae,  the  stage  in  which  the  injury  to  woolens, 
etc.,  is  done  having  noticeable  differences  in  habit.  The  moths  lay  their 
eggs  on  garments  and  stuffs,  preferably  woolen,  hanging  in  dark  closets  or 
stored  in  trunks  or  dressers,  and  the  small  white  larvae  feed  on  the  dry 
animal  fibers  of  which  the  cloth  is  made.  The  larva  of  the  most  familiar 
species,  the  case-bearing  clothes-moth.  Tinea  pellionella  (Fig.  527),  makes 
a  small  free  tubular  case  out  of  bits  of  cloth  fibers  held  together  by  silk'spun 
from  its  mouth;  the  larva  of  the  tapestry -moth  T.  tapetzella,  a  rarer  species, 
attacks  thick  woolen  things,  as  blankets,  carpets,  and  hangings,  burrowing 
into  the  fabric  and  forming  a  long  winding  tunnel  or  gallery  partially  lined 
with  silk;  the  larva  of  the  webbing  clothes-moth,  Tinea  biselliella,  a  species 
especially  common  in  the  Southern  States,  although  not  infrequent  in  the 
North,  spins  no  case  or  gallery,  but  makes  a  cobweb  covering  over  the 
substance  it  is  feeding  on.  The  larvae  of  all  the  species,  when  ready  to 
pupate,  make  a  cocoon  out  of  bits  of  woolen  tied  together  by  silken  threads 
in  which  to  transform.  The  moths,  on  issuing,  rest  during  the  day  on  the 
garments  or  stuffs,  but  fly  about  at  night,  often  coming  to  the  lights  in 
rooms.  They  are  all  small,  pellionella  and  biselliella  expanding  about  -j 
inch  and  tapetzella  |  inch;  pellionella  has  grayish-yellow  fore  wings  with- 
out  spots,  and   tapetzella   has    the  'fore  wings  black    at  base  and  creamy- 


Z.  p.  mlz.  I  uALF* 


The  Moths  and  Butterflies 


375 


white  with  some  grayish  on  the  middle  and  apex.  The  eggs  are  laid 
by  the  moths  directly  on  the  woolen  garments  or  other  articles  favored 
by  the  larval  palate,  and  several  generations  may  appear  each  year.  The 
remedies  for  clothes-moths  are  the  admission  of  light  into  closets  and  dressers, 
the  fumigation  of  infested  clothes  or  rugs  in  tight  chests  with  bisulphide 
of  carbon  (the  fumes  will  kill  every  larva  and  moth  in  the  chest),  and  the 
keeping  of  carpets,  rugs,  hangings,  and  garments  in  cold  storage  during 
summer  absences  from  home.  Send  the  things  to  a 
cold-storage  company  with  instructions  to  keep  at 
a  temperature  below  40°  F.  The  insects  cannot 
develop  in  a  temperature  below  this  point.  Cloth- 
covered  furniture  and  cloth-lined  carriages,  if  to  be 
left  long  unused,  may  be  sprayed  once  each  in  April, 
June,  and  August  with  benzine  or  naphtha. 

A  sometimes  serious  pest  of  stored  grains,  espe- 
cially corn  in  cribs,  is  the  Angoumois  grain-moth, 
Gelechia  cerealella.  The  larvae  bore  into  the  kernels, 
feeding  on  the  inner  starchy  matter.  I  have  seen  ears 
of  corn  in  Kansas  cribs  with  every  kernel  attacked. 
The  larvae  feed  for  about  three  weeks,  then  pupate 
inside  the  kernel,  the  moth  issuing  in  a  few  days. 
The  kernels  of  infested  ears  show  from  one  to 
three  little  holes  from  which  moths  have  issued. 
The  adult  moth,  expanding  about  half  an  inch,  is 
light  grayish  brown,  more  or  less  spotted  with  black, 
looking  much  hke  the  case-bearing  clothes-moth. 
The  eggs  are  deposited  on   grain  in   the  field  or  bin. 

Numerous  Tineid  species  are  known  as  leaf- 
miners  because  of  the  burrows  of  the  larvae.  Leaves 
of  various  trees  and  shrubs  often  show  whitish  blotches 
or  lines,  which  when  examined  closely  are  seen  to 
be  due  to  the  separation  of  the  epidermis  of  the  leaf 
from  the  inner  soft  tissue  or  to  the  complete  dis- 
appearance of  the  inner  tissue.  This  is  the  work  of 
the  tiny  burrowing  and  feeding  "leaf-miners,"  the 
larvae  of  certain  Tineid  species.  Often  the  miner, 
a  small  white  grub  with  the  usual  eight  pairs  of  legs  characteristic  of  Lepi- 
dopterous  larvae,  can  be  found  in  his  mine,  or,  perhaps  he  will  have  ceased 
feeding  and  have  transformed  to  a  small  light-brown  pupa.  The  species  of 
these  leaf-miners  are  many,  and  numerous  different  types  of  mines  may  be 
found;  the  winding  narrow  lines  called  serpentine  mines  common  on  wild 
columbine,  the  spotted  and  folded  tentiform  mines  on  the  wild  cherry  and  the 


Fig.  531. — Pupal  cocoons 
of  the  apple  bucculatrix, 
Bucculatrix  pomijoliella. 
(Twice  natural  size.) 


37^ 


The  Moths  and  Butterflies 


apple,  the  blotch-mines  of  the  oaks  and  other  forest  trees.  Even  pine- 
needles  are  mined  by  certain  species,  the  pine  leaf-miner,  Gelechia  pini- 
jolieUa,  being  abundant  in  the  leaves  of  pitch-pine. 

Interesting  little  Tineids  are  the  apple  and  oak  bucculatrix-moths,  whose 
larvae  feed  on  the  leaves  and  w\\tn  ready  to  pupate  crawl  to  a  stem  or  branch 


ff  r2r.3  r4 


'r-\--\  M  \        ^^  C2 

Fig.  532.  .  Fig.  533. 

Fig.  532. — The  apple-leaf  bucculatrix,  Bucculatrix  pomifoliella,  pupal  cocoons  on  twig, 
one  pupal  cocoon  removed,  and  moth.  (After  Riley;  cocoons  natural  size; 
size  of  moth  indicated  by  line.) 

Fig.  533. — Venation  of  a  Pyralid  moth,  P>'ra/:'5 /ar/;ja/f5.  C5,  costal  vein;  5C,  subcostal 
vein;  r,  radial  vein;  m,  medial  vein;  c,  cubital  vein;  a,  anal  veins.  Note  the  hair- 
like  projection,  called  frenulum,  at  the  base  of  the  anterior  margin  of  the  hind  wing. 
This  fits  into  a  little  "frenulum  pocket"  on  the  fore  wing.  (After  Comstock; 
enlarged.) 

and  there  make  long,  slender,  finely  woven  little  white  cocoons,  conspicuously 
ribbed  or  fluted  lengthwise,  in  which  they  pupate  (Figs.  531  and  532).  The 
pupae  hibernate,  the  tiny  moth  issuing  the  following  spring  and  laying  its 
eggs  on  the  leaves.  The  larva  are  miners  at  first,  but  after  the  first  moulting 
feed  on  the  outer  surface  of  the  leaves  under  thin  flat  silken  webs. 

The  PyraliJina  include  half  a  dozen  famiUes,  some  of  the  moths 
hardly  properly  called  microlepidoptera,  for  they  reach  a  wing  expanse  of 
i^  inches.  But  most  of  the  species  are  small  and  but  few  are  at  all 
familiar  to  collectors.  The  larvae  of  numerous  species  are  injurious  to 
fruits,  stored  grain,  etc.,  and  these  species  have  a  particular  interest  for 
economic  entomologists.  To  collectors  and  nature  students  the  most  attrac- 
tive Pyralids  will  be  the  beautiful  plume-moths,  or  feather-wings,  small 
moths  with  the  wings  split  or  fissured  longitudinally  for  one-half  or  more  the 
length  of  the  wing.  The  fore  wings  are  usually  thus  divided  into  two  parts 
and  the  hind  wings  into  three  (Fig.  534),  but  on  some  there  are  more  divisions. 
All  the  feather-wings  excepting  one  species  belong  to  the  family  Pteropho- 


The  Moths  and  Butterflies 


377 


ridte,  the  exception  being  a  small  moth  with  both  wings  deeply  cleft  into 
six  parts.  It  is  called  Orneodes  hexadadyla  and  is  considered  to  be  the 
sole  representative,  so  far  as  known,  of  a  distinct  family,  the  Orneodidai. 
Of  the  Pterophoridae  several  species  are  common  in  the  North  and  East. 


Fig.  534. 


Fig-  535- 


Fig.  534.  A  California  plume-moth.     (Natural  size.) 

Fig.  535. — The  raspberry  plume-moth,  Oxyptilus  tenuidactylus,  moth  and  larva.     (After 
Saunders;    moth  natural  size;    larva  much  enlarged.) 

Oxyptilus  tenuidactylus  (Fig.  535),  with  coppery  brownish  wings,  with  the 
plumes  deeply  fringed,  has  a  pale  yellowish-green  larva  that  feeds  on  rasp- 
berries and  blackberries;  O.  periscelidactylus  has  wings  of  a  metallic  yellow- 
ish brown,  with  several  dull  whitish  streaks  and  spots;  its  greenish-yellow 
caterpillars  with  scattered  small  tufts  of  white  hairs  feed  on  grape-leaves 
and  often  are  numerous  enough  to  do  much  damage.  Along  the  Pacific 
coast  the  plume-moths  are  not  at  all  uncommon. 


Tig.   536. — ^The  Mediterranean  flour-moth,  Ephestia  kuehniella;  larva,  pupal  cocoon, 
pupa,  and  moth.     (One  and  one-half  times  natural  size.) 


The  Crambids,  or  close-wings,  are  numerous  and  perhaps  more  familiar 
than  any  other  family  of  the  Pyralidina.  The  larvae  of  most  of  the  species 
feed  on  grass,  and  the  adults  fly  up  before  one  as  one  walks  through  meadow 
or  pasture.  They  may  easily  be  recognized  by  their  characteristic  habit  of 
closely  folding  their  wings  about  the  body  when  at  rest.  The  fore  wings 
often  present  pretty  designs  in  silver,  gold,  yellow,  brown,  black,  and  white, 


378 


The  Moths  and  Butterflies 


or  they  may  be  uniformly  dull-colored;  the  hind  wings  are  white  or  grayish. 
The  palpi  are  long  and  project  conspicuously,  so  that  snout-moth  is  a  name 
often  given  to  the  Crambids. 

Pretty  little  moths  with  shining  black  wings,  two-spotted  with  white  on 
the  front  ones,  and  one-  or  two-spotted  on  the  hind  wings,  are  the  Desmias, 
of  which  the  species  maculalis,  the  grape-vine  leaf-folder,  is  especially  common, 
and  often  seriously  injurious.  The  larvae  fold  or  roll  up  grape-leaves  and 
feed  concealed  inside  the  roll,  skeletonizing  the  leaf  by  eating  away  all  of  its 
soft  tissues.  The  larva  when  full-grown  is  a  little  less  than  an  inch  long, 
glossy  yellowish  green,  and  very  active  when  disturbed.  It  pupates  within 
the  folded  leaf.     It  is  abundant  in  the  South. 

Among  the  insects  that  attack  stored  grain,  flour,  meal,  etc.,  are  several 
Pyralids.  The  meal  snout-moth,  Pyralis  jarinalis,  is  a  common  pest, 
the  larvae  making  long  tubes  of  silk  in  the  meal,  and  taking  readily  to  cereals 


^m^m^^^^m^ 


Fig.  537. — A  curious  hammock  and  its  maker,  Coriscum  ciiculipennellitm,  a  leaf-rolling 
moth,  whose  larva  pupates  in  the  odd  little  hammock  shown  in  the  figure.  (After 
photographs  by  Slingerland;  natural  size  of  moth  indicated  by  line;  hammock 
natural  size;  a  rose-leaf  enlarged.) 

of  all  kinds  and  conditions,  in  the  kernel  or  in  the  form  of  meal,  bran,  or 
straw.  The  moth  expands  one  inch,  the  wings  being  light  brown  with  red- 
dish reflections  and  a  few  wavy  transverse  lines.  The  Indian  meal-moth, 
Plodia  inter punctella,  is  another  familiar  pest  in  mills  and  stores,  its  small 
whitish  larva,  with  brownish-yellow  head,  feeding  on  dry  edibles  of  almost 
every  kind,  as  meal,  flour,  bran,  grain  of  all  sorts,  dried  fruits,  seeds,  and  nuts, 
condiments,  roots,  and  herbs.  It  spins  webs  of  silk  with  which  it  fastens 
together  particles  of  the  attacked  food,  making  it  unfit  for  our  use.  The  moth 
expands   f  inch  and  has  the  fore  wings  cream-white  at  base  and  reddish 


The  Moths  and  Butterflies  379 


brown  with  transverse  blackish  bands  on  disk  and  apex.  Another  and  per- 
haps the  most  formidable  of  all  mill  pests  is  the  notorious  Mediterranean 
flour-moth,  Ephestia  kiiehniella  (Fig.  536).  This  insect  first  became  seri- 
ously harmful  in  Germany  in  1877,  soon  invading  Belgium  and  Holland 
and  by  1886  having  got  a  foothold  in  England.  Three  years  later  it 
appeared  in  Canada  and  since  1892  it  has  been  a  pest  in  the  United  States. 
The  moth,  which  expands  a  little  less  than  an  inch,  with  pale  leaden-gray 
fore  wings,  bearing  zigzag  black  and  transverse  bands  and  semi-transparent 
dirty-whitish  hind  wings,  lays  its  eggs  where  the  hatching  larvae  can  feed  on 
flour,  meal,  bran,  prepared  cereal  foods  or  grain.  The  caterpillars  spin 
silken  galleries  as  they  move  about,  which  make  the  flour  lumpy  and  stringy 
and  ruin  it  for  use.  In  addition  to  this  direct  injury,  the  mill  machinery 
often  becomes  clogged  by  the  silk-filled  flour  and  has  to  be  frequently  stopped 
and  cleaned,  involving  in  large  mills  much  additional  loss.  When  a  mill 
becomes  badly  infested  the  whole  building  has  to  be  thoroughly  fumigated 
by  carbon  bisulphide,  an  expensive  and  rather  dangerous  process.  Unin- 
fested  mills  should  be  tightly  closed  at  night  (if  not  running  continuously) 
and  every  bushel  of  grain,  every  bag  or  sack  brought  into  the  mill,  should 
be  subjected  to  disinfection  by  heat  or  the  fumes  of  bisulphide  of  carbon. 

An  interesting  as  well  as  economically  important  little  Pyralid  is  the 
bee-moth,  Galleria  tnellonella,  whose  larvae  live  in  beehives,  feeding  on  the 
wax  combs.  The  moths  find  their  way  into  the  hives  at  night  to  lay  their 
eggs.  This  has  to  be  done  very  quickly,  however,  as  bees  are  alert  even  at 
night  to  defend  themselves  against  this  insidious  enemy.  I  have  intro- 
duced bee-moths  into  glass-sided  observation-hives  both  by  day  and  night, 
and  in  each  case  the  moths  were  almost  immediately  discovered,  stung  to 
death  and  torn  to  pieces  in  a  wild  frenzy  of  anger.  Many  must  be  killed 
where  one  succeeds  in  getting  its  eggs  deposited  inside  the  hive.  The  squirm- 
ing grub-like  white  larvae  protect  themselves  by  spinning  silken  webs  and 
feed  steadily  on  the  wax,  ruining  brood-  and  food-cells  and  interfering  sadly 
with  the  normal  economy  of  the  hive.  When  ready  to  pupate  they  spin 
very  tough  bee-proof  silken  cocoons  within  which  they  transform  to  other- 
wise defenceless  quiescent  pupai.  Bee-moths  often  become  so  numerous 
in  a  hive  as  to  break  up  the  successful  life  of  the  community.  I  have  taken 
thousands  of  pupae,  lying  side  by  side  like  mummies  in  sarcophagi  in  their 
impervious  stiff  silken  cocoons,  from  a  single  hive  from  which  the  bees  had 
all  fled. 

Third  of  the  superfamilies  of  microlepidoptera  is  the  Tortricina,  com- 
prising three  families,  two  of  which  number  many  species.  The  Tortricid 
moths  get  their  name  from  the  habit,  common  to  the  larvae  of  many  of  them, 
of  rolling  up  the  edges  or  the  whole  of  leaves  in  which  to  lie  protected  while 
feeding,  and  later  while  in  quiescent  pupal  stage.    Not  all  leaf-roUers  are 


38< 


The  Moths  and  Butterflies 


Tortricids,  but  the  majority  of  rolled-up  leaves  so  commonly  seen  on  shrubs 
and  trees  are  the  homes  of  these  larvae.  A  number  of  species  belonging  to 
the  genus  Cacoecia  are  among  the  commonest  and  most  important  of  these 
because  they  prefer  the  leaves  of  apple,  plum,  and  cherry  trees,  and  currants, 
raspberries,  gooseberries,  strawberries,  cranberries,  roses,  etc.,  rather  than 

those    of    trees    and   shrubs 
-^'-^ — iif  ^  whose    healthfulness    is   not 

so  important  to  us.  The 
larvae  of  Cacoecia  rosaceatia, 
the  oblique-banded  1  e  a  f  - 
roller,  pale  yellowish-green 
caterpillars  |  inch  long,  dis- 
figure and  injure  many  kinds 
of  fruit-trees,  small  fruits, 
and  garden  shrubs.  The 
moth  expands  about  one 
inch,  and  has  reddish-brown 
body,  light,  cinnamon-brown 
fore  wings  crossed  by  wavy 
dark-brown  lines  and  ochre- 
yellow  hind  wings.  Choke- 
berries,  and  cultivated  cher- 
ries as  well,  are  often  attacked 
by  the  cherry-tree  leaf-folder, 
C.  cerasivorana  (Fig.  538),  whose  active  yellow  larvae  "fasten  together  with 
silken  threads  all  the  leaves  and  twigs  of  a  branch  and  feed  upon  them, 
an  entire  brood  occupying  a  single  nest.  The  larvae  change  to  pupae  within 
the  nest;  and  the  pupae  when  about  to  transform  work  their  way  out  and 
hang  suspended  from  the  outer  portion  of  the  nest."  The  moths  expand 
from  -f  to  i^  inch,  have  bright  ochre-yellow  wings  with  brownish  spots,  and 
bands  of  pale  leather-blue  on  the  front  ones. 

The  oak  leaf-roller,  C.  pervadana,  similarly  makes  ugly  nests  in  oak- 
trees  in  late  summer,  each  nest  consisting  of  a  wad 
of  tied-together  leaves.  Cranberry-plants  are  sometimes 
attacked  by  reddish,  yellow-headed,  warty-backed  cater- 
pillars, which  are  the  larvae  of  C.  parallela  (Fig.  540), 
a  leaf-roller  moth  with  reddish-orange  fore  wings  crossed 
diagonally  by  numerous  fine  Hnes  of  a  darker  red-brown, 
and  a  pair  of  broad  oblique  red-brown  bands.  The  hind 
wings  are  pale  yellow. 

Notwithstanding  the  apparently  sufficient  protection  afforded  the  leaf- 
rolling  larvae  by  their  tightly  rolled  cylindrical  cases  and  webby  nests,  birds 


Fig.  540. 


Fig.  538. — The  cherry-tree  leaf-roller,  Cacoecia  cera- 
sivorana.    (After  Lugger;  natural  size.) 

Fig.  53Q. — Venation  of  a  Tortricid,  Cacoecia  cera- 
sivorana. cs,  costal  vein;  sc,  subcostal  vein; 
r,  radial  vein;  m,  medial  vein;  c,  cubital  vein; 
a,  anal  vein.     (After  Comstock;    enlarged.) 

Fig.  540. — The  cranberry  leaf-roller,  Cacoecia  paral- 
lela.    (After  Lugger;  natural  size.) 


Fig.  541.  —  The 
sulphur-colored 
tortrix,  Dichelia 
siiljureana.  (Af- 
ter Lugger;  nat- 
ural size.) 


The  Moths  and  Butterflies 


381 


Fig.  542. — The  rus- 
set-brown tortrix, 
Platynota  flavedana. 
(After  Lugger; 
natural  size.) 


may  often  be  seen  cleverly  engaged  in  extracting  one  by  one  the  toothsome 

morsels  from  their  homes.     Hovering  over  a  rolled  leaf,  the  bill  is  carefully 

thrust  into  the  roll  for  the  unseen  caterpillar  and  rarely  vi^ithdrawn  without 

it.     Lugger  says  that  the  Baltimore  oriole  is  particularly  expert  at  this  sort 

of  hunting  unseen  prey. 

A  certain  Tortricid,  accidentally  imported  many  years  ago  from  Europe,  has 

become  one  of  our  serious  grape  pests.     This  is  the  grape-berry  moth,  Eu~ 

demis  botrana,  whose  small  slender  whitish-green,  black- 
headed  larvx^  bore  into  green  and  ripening  grapes  and 

feed  there  on  the  pulp  and  seeds.     When  full-grown  the 

larva  becomes  olive-green  or  dark  brown  and,  forsaking 

the  grape-berry,  cuts  out  of  a  grape-leaf  a  little  flap  which 

it  folds  over  and  fastens  with  silk,  thus  forming  a  small 

oblong  case  within  which  it  pupates.    The  moth  expands 

finch,  and  has  slaty-blue  fore  wings,  marked  with  dark 

reddish-brown  bands  and  spots,  while  the  hind  wings  are  uniform  dull  brown. 

Another  well-known   Tortricid   pest  is  the   bud-moth,    Tmetocera    ocellana 

(Fig.  543),  whose  larvae  burrow  into  opening  fruit-  and  leaf -buds  on  apple- 
trees  and  eat  them.  The  moth  expands  f  inch  and  is 
dark  ashen-gray  with  a  large  irregular  whitish  band  on 
the  fore  wing. 

By  far  the  best  known  and  most  feared  and  hated 
Tortricid  is  the  codlin-moth,  Carpocapsa  pomonella  (Figs. 
545  and  546),  the  most  important  enemy  of  the  apple- 
grower.  Distributed  all  over  the  United  States,  wherever 
apples  are  grown,  minute  and  obscure  so  as  to  be 
easily  overlooked  until  fairly  intrenched  in  the  orchard, 

prolific  and  subject  to  no  very  disastrous  parasitic  attacks,  this    frail    little 

species  causes  losses  to  fruit-growers  of  no  less  than  $10,000,000  annually. 

The  moth,  which  hides  by  day  and   is    seldom   seen,  has    the    fore  wings 

marked  with  alternate    irregular    transverse  wavy  streaks  of   ash-gray  and 

brown,  with  a  large   tawny  spot   on  the  inner 

hind     angle,    the    hind    wings    and    abdomen 

light  yellowish  brown  with  a  satiny  luster.     It 

lays  its  eggs  (for  the  first  generation,  the  species 

being  two-brooded  over  most  of  the   country) 

in  the  calyx  of  the  newly  forming  apple,   or 

sometimes,  as  recently  observed  in  California, 

on  the  side  of  the  tiny  fruit.     The  larvae,  hatch- 
ing in  from  three  to  five  days,  begin  to  feed  on 

the  green  fruit,  soon  burrowing  into  its  center. 

They   become  full-grown   before   the   apples  ripen,  burrow  out   and   crawl 


Fig.  543, — The  eye- 
spotted  bud-moth, 
Tmetocera  ocellana. 
(After  Lugger; 
natural  size.) 


Fig.  544. — The  cranberry 
worm-moth,  Rhopotota  vac- 
ciniana.  (After  Lugger; 
natural  size  indicated  by 
line.) 


382 


The  Moths  and  Butterflies 


away  to  some  crevice  in  the  bark  or  sheltered  place  on  the  ground,  and 
there  pupate.  In  two  weeks  the  moths  issue  and  deposit  eggs  on  later 
apples  for  the  second  brood.  The  larvae  of  this  brood  are  tucked  away 
in  the  fall  and  winter  apples  when  gathered,  and  are  thus  carried  with 
them  into  cellars,  warerooms,  etc.  They  soon  issue  from  the  fruit,  and 
finding  concealed  spots  in  the  cracks  of  barrels  or  boxes  or  elsewhere 
near  the  stored  apples,  pupate,  the  pupae  lasting  over  the  winter  and 
the  moths  issuing  about  apple-blossoming  time  the  following  spring.  The 
pupae  are  protected  by  thin  papery  cocoons  of  silk  spun  by  the  larvae.  The 
remedies  are  effective,  but  must  be  carefully  and  regularly  used.  Spraying 
the  young  fruit  with  an  arsenical  mixture,  as  Paris  green  or  London  purple, 
soon  after  the  blossoms  fall  and  again  in  about  two  weeks,  will  reduce 
immensely  the  possible  loss.     Banding  the  tree  with  strips  of  old  carpet  or 


Fig.    545. — The   larva  or   worm    of    the   codlin-moth,    Carpocapsa   pomonella.     (After 
photograph  by  Shngerland;    three  times  natural  size.) 

sacking  at  the  time  the  larvae  are  crawling  out  of  the  apples  and  hunting 
for  concealed  places  in  which  to  pupate,  will  enable  the  grower  to  trap  and 
destroy  thousands  of  them  and  thus  greatly  lessen  the  numbers  in  the  second 
brood.  All  fallen  fruit  should  be  promptly  gathered  and  destroyed  in  such 
a  way  as  to  kill  the  larvae  inside. 

An  interesting  insect  closely  allied  to  the  codlin-moth  is  the  Mexican 
jumping  bean-moth,  Carpocapsa  saltitans  (Fig.  547),  which  lays  its  eggs 
on  the  green  pods  of  a  euphorbiaceous  plant  of  the  genus  Croton.  The 
hatchino-  larvae  bore  into  the  growing  beans  in  the  pod,  but  do  not  attain 
their  full  growth  until  after  the  beans  are  ripe  and  hard.  The  ripe  beans 
with  the  squirming  larvae  inside  act  as  if  bewitched,  twitching  and  jerking, 
rolUng  over  and  leaping  shghtly  clear  of  the  table  or  desk  on  which  they 


The  Moths  and  Butterflies 


383 


may  rest.  The  larva;  pupate  within  the  beans,  first  gnawing  a  circuUu 
thin  place  through  which  the  moth  may  push  its  way  out.  Another  Tor- 
tricid  moth,  Grapholitha  sebastiance,  has  similar  habits.  Most  of  the  jump- 
ing beans  come  from  the  Mexican  province  of  Chihuahua. 


Fig.  546. — Pupae,  in  cocoons,  of  codlin-moth,  Carpocapsa  pomonella.     (After  photograph 
by  Slingerland;    enlarged.) 

A  few  moth  families,  represented  in  this  country  by  but  few  species,  may 
now  be  referred  to  briefly,  chiefly  for  the  sake  of  mentioning  certain  par- 
ticular forms  that  are  fairly  common  and  wide-spread  and  hence  likely  to 
be  taken  by  the  collector. 

The  flannel-moth  family,  Megalopygidae,  includes  but  five  North  Ameri- 
can species,  of  which  the  crinkled  flannel-moth,  Lagoa  crispata,  pale  straw- 
yellow,  with  long,  curling,  woolly, 
brownish  and  blackish  hairs,  with 
wing  expanse  of  about  i  inch,  is 
not  uncommon  in  the  north  Atlantic 
states,  while  Megalopyge  opercularis, 
of  about  the  same  size,  with  yel- 
lowish-white fore  wings  overspread 
except  at  the  tips  by  woolly  purpHsh-  Fig.  547.— The  Mexican  jumping  bean-moth, 
brown    hairs,    is    not    uncommon     in         C<^rpocapsa   saltitans;   pupa    croton-bean 

from  which  moth  has  issued,  and  moth, 
the    southern    states.      The  flannel-       (Natural  size.) 

moth    caterpillars    have    seven  pairs 

of  abdominal  prop-legs  instead  of  five,  the  number  common  to  almost  all 
other  caterpillars,  and  the  cocoons  in  which  the  pupae  lie  have  a  hinged 
door  for  the  exit  of  the  moth.  The  larva  of  M.  opercularis  looks  like  an 
animated  bit  of  cotton-wool  or  lock  of  white  hair.  That  of  L.  crispata 
feeds  particularly  on  blackberry,  raspberry,  and  apple;  it  is  nearly  oval 
in  shape,  covered  with  evenly  shorn  brownish  hairs,  which  form  a  ridge 
along  the  middle  of  the  back.     When  about  \  inch  long  it  ceases  to  feed 


384 


The  Moths  and  Butterflies 


and  spins  a  tough  oval  cocoon  fastened  securely  to  the  side  of  a  twig. 
The  moth  issues  in  the  summer  of  the  following  year.  The  cocoon  of  M. 
opercularis  so  closely  resembles  a  terminal  bud  of  the  Southern  live-oak  on 
which  the  caterpillars  mostly  feed  that  it  is  almost  impossible  to  detect  it, 
especially  as  both  twigs  and  cocoons  are  covered  with  small  bits  of  lichen. 

Another  small  family,  with  thirty-three  species,  of  interest  because  of 
the  odd  character  of  the  larvae,  is  that  of  the  slug-caterpillar  moths,  the 
Eucleidae  (or  Cochlidiida?).  The  moths  themselves  are  small  and  stout, 
mostly  rather  strikingly  colored,  with  brown,  apple-green,  and  cinnamon 
prevailing.  The  larvte  are  slug-like,  short,  thick,  nearly  oblong  and  mostly 
spiny  and  gaudily  colored.  The  spiny  oak-slug,  formidably  armed  with 
branching  spines  and  common  on  oaks  and  willows  in  the  east,  is  the  larva 
of  Euclea  delphinii,  a  small,  robust,  deep-reddish-brown  moth  with  bright 
green  spots  on  the  wings.  The  saddle-back  caterpillar,  Sibine  (Empretia) 
stimidea',  has  a  striking  squarish  green  blotch  on  the  back,  with  an  oval  pur- 
plish spot  in  the  middle.  It  has  branching  spiny  hairs,  which  affect  some 
persons  like  nettles,  producing  severe  inflammation.  It  feeds  on  many 
plants,  on  oak  and  other  forest  trees  in  the  east,  and  often  on  corn  in  the 
west.  The  moth  is  lustrous  seal-  and  chocolate-brown,  with  a  few  small 
white  dots  on  the  wings.  Another  slug-caterpillar  is  the  pale  apple-green 
larva,  with  dorsal  brown  blotch,  of  Prolimacodes  (Eulimacodes)  scapha, 
a  stout  wood-brown  moth,  expanding  one  inch,  with  a  curved  silvery  line 
on  each  fore  wing,  behind  which  the  wing  surface  is  paler  than  in  front. 
None  of  the  species  of  this  family  has  been  found  west  of  the  Rocky  Moun- 
tains except  in  Texas.  Parasa  chloris  has  the  fore  wings  brown  at  base 
and  outer  margin  and  elsewhere  apple-green;  the  hind  wings  are  clayey 
yellow.  Its  larva  is  bright  scarlet  with  four  blue-black  lines  along  the  back 
and  with  stinging  yellow  tubercles.  It  feeds  on  cherry,  apple,  and  rose. 
Euclea  pcemdata  has  chocolate-brown  fore  wings  with  an  irregular  bright 
green  elongate  curving  blotch,  and  the  hind  wings  soft  wood-brown. 

The  most  extraordinary  species  in  this  family  of  moths  with  strange 
larvae  is  the  hag-moth,  Phohetron  pitheciutn,  whose  larva  is  one  of  the 
oddest  known.  It  is  nearly  square,  dark  brown,  and  bears  eight  singular 
fleshy  processes  projecting  from  the  sides.  These  processes,  which  are  half 
as  long  as  the  larva  itself,  are  covered  with  feathery  brown  hairs,  among 
which  are  longer  black,  stinging  hairs.  Thus  covered,  and  twisting  curi- 
ously up  and  back,  they  resemble  heavy  locks  of  hair  and  give  the  name 
hag-moth  to  the  species.  The  moth  is  rarely  seen;  it  is  dusky  purple- 
brown  with  ocherous  patches  on  the  back  and  a  light  yellow  tuft  on  each 
middle  leg;  the  fore  wings  are  variegated  with  pale  yellowish  brown,  and 
crossed  by  a  narrow  wavy  curved  band  of  the  same  color;  the  hind  wings 
are  sable,  bordered  with  yellowish  in  the  female. 


The  Moths  and  Butterflies 


385 


Much  larger  moths  are  the  Cossidaj,  or  carpenter-moths,  with  slender, 
smooth,  spindle-shaped  bodies  and  long,  narrow-pointed,  strong  wings  hke 
those  of  the  hawk-moths  (Sphingidtc).     The  larva)  are  wood-borers,  bur- 
rowing about  in  the  heart-wood  of  locust-  and  other  shade-trees  and  also  of 
apple-,  pear-,  and  other  fruit-trees.     The  moths  are  mostly  gray,   vaguely 
patterned  with  white  and  blackish,  although  a  few  are  conspicuously  black- 
and-white  spotted.     They  have  no  proboscis  and  hence  can  take  no  food. 
The  moths  fly  at  night  and  lay  their  eggs  on  the  bark  of  the  trees,  the  hatch- 
ing, grub-like,  naked  larvae  burrowing  into  the  hard  wood,  where  they  Hve 
for  from  two  to  four  years,  when  they  make  in  their  tunnel  a  thin  cocoon 
of  silk  and  chewed  wood  to 
pupate  within.    When  ready 
to     transform,     the      pupa 
wriggles    along    the  tunnel 
to  its  opening,  so  that   the 
issuing  moth  finds  itself  in 
free    air.      The    locust-tree 
carpenter-moth,   Prionoxys- 
tus   robinm    (Fig.    549),  or 
goat-moth,    so   called    from 
its   curious  offensive    odor, 
expanding  i^  inches  (males) 
to  2\  inches  (females),  has 
gray   wings    with   irregular 
black    lines    and    spots    in 
the     female,     and      darker 
fore    wings    and    yellowish 
hind    wings    in    the    male. 
Its    larvce    feed  on    locust- 
trees  and  are    often    abun- 
dant enough  to  do  much  injury.     The  wood  leopard-moth,  Zeiizera  pyrina, 
is  strikingly  spotted  with  black  on  a  white  ground  color,  and  is  common  in 
certain  eastern  cities,  its  larvae  infesting  maples  and  other  shade-trees.     On 
'  the   Pacific  coast   the  poplar  carpenter-moth,  Cossus   popidi,  with  whitish 
fore  wings  shaded  all  over  with  blackish  and  irregular  black  Hnes,  and  hind 
wings  yellowish  gray,  growing  darker  at  the  outer  margin,  is  common,  its 
larvae  infesting  poplars  and  cottonwoods.     There  are  only  twenty  species 
in  North  America  belonging  to  this  family. 

FamiUar  curiosities  of  entomology  are  the  moving  bags  of  silk  and  bits 
of  twigs  and  needles  occasionally  found  in  cedars,  firs,  and  arbor  vitae.  The 
"worms"  which  make  these  bags  and  carry  them  around,  with  all  the  body 
inside  except  the  projecting  head  and  thoracic  legs,  are  the  larvae  of  the 


Fig.  548. — Venation  of  a  Cossid,  Prionoxystus  robinia. 
cs,  costal  vein;  sc,  subcostal  vein;  r,  radial  vein; 
m,  medial  vein;  c,  cubital  vein;  a,  anal  veins.  (After 
Comstock;  enlarged.) 


386 


The  Moths  and  Butterflies 


bag- worm  moth,  Thyridopteryx  ephemera;  for  mis  (Fig.  550),  the  females  of 
which  are  wingless,  the  males  with  blackish  body  and  clear  brown-veined 
wings  which  expand  an  inch.  This  moth  is  the  most  common  and  wide- 
spread of  the  thirteen  moth  species  which  constitute  the  family  Psychids,  as 
represented  in  this  country.  In  the  Southern  States  a  common  species  is 
Abbott's  bag-worm,  Oiketicus  abbotti,  whose  larvae  make  bags  with  the  bits 
of  twigs  fastened  regularly  transversely,  the  male  moth  expanding  ij  inches 
and  being  sable-brown  with  a  clear  bar  in  the  middle  of  each  fore  wing. 
Smaller  bag-worm  moths  are  the  three  species  of  the  genus  Psyche,  the  males 
expanding  from  ^  inch  to  |  inch,  P.  conjederata,  the  best  known,  being  all 


Fig.  549. — The  locust-tree  carpenter-moth,  Prionoxystus  robittics,  male  and  female 
moths,  young  larva  and  empty  pupal  case.  (After  Lugger;  moths  and  pupal  case 
natural  size;    young  larva  enlarged.) 

blackish  with  opaque  wings,  P.  gloveri,  a  Southern  species,  dark  brown  through- 
out, and  P.  carbonaria,  a  Texas  form,  brownish  black  with  subtranslucent 
wings.  The  females  of  all  the  Psychids  are  wingless.  The  larvae,  after 
moving  about  over  the  tree  and  feeding  until  full-grown,  pupate  within  their 
bags,  and  the  issuing  wingless  grub-like  females  simply  remain  in  the  sac 
until  found  by  a  flying  male,  after  which  they  lay  their  eggs  in  the  bag  and 
die.  The  male  Psychids  can  be  readily  distinguished  from  other  moths  by 
the  growing  together  of  the  anal  veins  of  the  fore  wings  until  they  appear 
to  be  a  single  branching  vein  (Fig.  552). 

The   smoky-moths,   Pyromorphidae,  of  which  but  fifteen   species  occur  , 
in  the  United  States,  are  small,  expanding  from  -|  inch  to  i  inch  (a  single 
Western  species  expands  ij  inches),  and  with  blackish  ground-color  on  body 


The  Moths  and  Butterflies 


387 


and  wings,  relieved  by  brilliant  patches  of  red,  yellow,  and  orange.  They 
are  favorites  with  collectors  and,  though  few  in  number,  are  not  at  all  uncom- 
mon. The  larvai  feed  on  the  leaves  of  various  plants,  but  grape  and  Vir- 
ginia creeper  seem  to  be  specially  liked.  Vineyards  indeed  often  suffer 
from  the  presence  in  considerable  numbers  of  smoky-moth  caterpillars. 
These  caterpillars  often  show  a  striking  gregarious  instinct,  massing  side 
by  side  in  lines  while  feeding.  The  small  black  and  yellow  larvae  of  Har- 
risina  americana,  a  common  Eastern  species,  may  often  be  found  arranged 


Pig.  550. — The  bag-worm  moth,  Thyridopteryx  ephemercejormis;  eggs,  larva,  pupa 
bag  containing  larva,  bag  containing  pupa,  male  moth.  (After  Felt;  about  natural 
size  except  the  eggs.) 

side  by  side  in  single  line  clear  across  a  grape-leaf.  Feeding,  when  young, 
only  on  the  soft  tissues  of  the  leaves,  they  skeletonize  them;  when  older, 
however,  they  eat  everything  but  the  larger  veins.  When  full-grown  they 
disperse,  each  finding  a  sheltered  spot,  where  it  makes  a  tough,  oblong- 
oval  cocoon  of  parchment-like  silk,  in  which  it  pupates.  The  moth  of  this 
species  expands  one  inch,  is  bluish  or  greenish  black,  with  orange  protho- 
racic  collar  broad  above  and  narrow  below,  and  narrow  subtranslucent 
wings.  It  flies  slowly  and  unevenly  during  the  warmest,  brightest  hours 
of  the  day,  frequenting  flowers.  H.  coracina,  found  in  Texas  and  Arizona, 
expands  |  inch  and  is  all  dull  black  with  a  bluish  tinge  on  the  abdomen;  H. 
metallica^  the  largest  Pyromorphid,  found  in  Texas  and  Arizona,  expands 
1 1  inches  and  is  lustrous  bluish  green  with  orange  prothorax.    Acoloithus 


The  Moths  and  Butterflies 


jaJsariiis,  one  of  the  smallest  members  of  the  family,  expanding  f  inch,  com- 
mon in  the  East,  is  black  with  very  narrow  reddish  collar.  Pyromorpha 
dimidiaUi,  expanding  i  inch,  common  in  the  Atlantic  states,  is  black  with 
translucent  wings.     The  only  other  genus  in  the  family  so  far  unmentioned 

is  Triprocris  with  eight  species,  all 
confined  to  the  western  states  and  all 
but  two  of  them  marked  on  body  or 
wings  with  orange  or  yellowish. 

Of  unusual  and  often  very  deceptive 
appearance  are  the  clear-wing  moths, 
or  Sesiidae.  With  their  often  brightly 
colored  black  and  yellow  or  red- 
banded  tapering  or  plump  bodies  and 
partly  or  wholly  clear  wings,  they 
resemble  strongly,  at  first  glance,  wasps 
or  bees,  and  are  undoubtedly  often 
taken  to  be  such  and  thus  left  unmo- 
lested by  both  collectors  and  birds,  two 
of  their  destructive  enemies.  For  birds 
like  almost  all  moths  for  food,  and 
collectors  especially  prize  the  Sesians 
for  the  sake  of  their  attractiveness 
and  the  sporting  character  of  their  pur- 
suit and  capture,  for  they  are  among 
the  swiftest  of  the  moths.  They  fly 
in  bright  sunlight,  visiting  flowers, 
and  thus  by  their  habits  further  in- 
crease their  likeness  to  wasps  and  bees. 
There  are  one  hundred  species  in  the 
family  in  this  country,  and  almost  all 
have  one  or  both  wings  partly  or  mostly 
clear,  i.e.,  free  from  scales.  A  few 
moths  of  other  families,  as  the  clear- 
winged  sphinges  and  others,  have  simi- 
larly partly  clear  wings,  but  the  very 
narrow  fore  wings  and  widely  expanded 
bases  of  the  hind  wings  will  distinguish  the  Sesians  from  the  few  other 
scattered  clear-winged  moths.  The  larvae  are  borers,  mining  in  roots  of 
fruit-trees,  the  canes  and  roots  of  small  fruits,  or  in  the  stems  of  herbaceous 
plants.  They  are  grub-like  and  yellowish  white,  with  darker  head  and  legs. 
When  abundant  they  become  very  injurious,  the  notorious  peach-tree  borers 
being  probably  the  most  serious  insect  enemy  of  the  peach-tree. 


Fig.  551. — Bag-worm  ;  the  larva  of  a  moth 
that  builds  a  protecting  case  out  of 
silk  and  bits  of  sticks,  in  which  its 
whole  body  except  homy  head,  thorax, 
and  legs  is  concealed.     (Natural  size-) 


The  Moths  and  Butterflies 


389 


rs 


■:^*4f 


For  one  hundred  and  fifty  years  the  peach,  an  imported  plant,  has  suffered 
in  this  country  from  the  ravages  of  this  native  pest.  One  Sesian  species, 
Sanninoidea  exitiosa  (Fig.  554)  is 
the  peach-tree  borer  of  the  eastern 
states,  and  another,  closely  related, 
S.  pacifica,  works  equal  injury  in  the 
Pacific  states.  In  both  species  the 
eggs  (Fig.  555)  are  deposited  on 
the  trunk  of  the  tree  near  its  base, 
in  July  and  August  in  the  East,  in 
April  and  May  in  California,  and 
the  young  larva;  (Fig.  556),  hatching 
after  a  week  or  ten  days,  immedi- 
ately bore  in  through  the  outer 
bark  and  begin  feeding  on  the 
live  inner  bark.  When  winter 
comes  they  cease  feeding — in  the 
East  a.  Ieas,-and  hibernate  quies-  ^'yil^ZTlt"Ti;T4!:^:'tf:- 
cent,  being  now  about  half-grown.  merajormis.  cs,  costal  vein;  sc,  subcostal 
In  the    spring    they   become   active       ^^in;    r,    radial    vein;    m,    medial   vein;    c, 

^        °  -^  cubital  vein;  a,  anal  veins, 

again,  feed  and  grow  rapidly,  and 

by  summer    are    ready  to   pupate.     Pacifica  begins  pupating  in  California 

in  February.  For  this  they  leave 
their  burrows,  come  out  to  the 
surface  of  the  bark,  spin  about 
themselves  a  thin  silken  cocoon 
and  change  (Fig.  557).  The 
pupal  stage  lasts 
weeks,  when  the 
The  clear-winged 
expanding  i  inch,  are  deep 
steely-blue,  with  small  golden- 
yellow  markings  on  head  and 
thorax  and  abdomen;  the  larger, 
heavier-bodied  female,  expanding 
a       a      a        "*  i|inches,has  a  broad  orange  band 

Fig.  553. —Venation  of  a  Pyromorphid,  Pyro-  across  the  abdomen  in  the  fourth 
morpha  dimidiata.  cs,  costal  vein;  5C,  sub-  q^.  f^^^]^  segments,  and  has  the 
costal  vein;    r    radial  vein;    m,  medial   vein;  .  ,      .  ,    ,  ,      1  ■  1 

c,  cubital  vein;   a,  anal  veins.      (After  Com-  front  wmgs  covered  With  blackish 
stock;   enlarged.)  scales    (Fig.    554).     The    remedy 

for    this   pest   is  the  application,  by  painting  on,    of  gas  tar  to  the  basal 
part  of  the  tree-trunk  just  before   the   flying   and   egg-laying   time  of  the 


about  three 
moths  issue, 
male    moths, 


390 


The  Moths  and  Butterflies 


moths;   this  prevents  the  females  from  ovipositing  on  the  treated  trees.     Or 
the  base  of  the  trunk  may  have  a  newspaper  tied  about  it. 


Fig.  554. — Moths  of  the  peach-tree  borer,  Sanninoidea  exitiosa,  the  upper  one  and  the 
one  at  the  right  being  females.     (Photograph  from  hfe  by  Shngerland;  natural  size.) 

The    currant-borer,   Sesia  tipuliformis,    expanding    three-fourths   of   an 
inch,  has  a  robust  body  with  a  fan-hke  tuft  of  scales  at  the  posterior  tip, 


Fig.  555. — Eggs  of  peach-tree  borer,  Sanninoidea  exitiosa.     (After  Slingerland;  natural 
size  at  n;  one  egg  enlarged  at  I;  micropyle  end  of  egg  greatly  enlarged  at  m.) 

dark  abdomen  ringed  with  yellow,  and  yellow  lines  on  the  thorax;  the  eggs 
are  laid  on  currant-canes,  and  the  hatching  larvae  burrow  into  the  center 
and  then  tunnel  longitudinally  in  the  pith.  They  hibernate  in  the  cane 
as  larvae,  not  pupating  until  ihe  following  summer,  when  the  moths  escape 


The  Moths  and  Butterflies 


391 


through  holes  in  the  cane  thoughtfully  made  by  the  strong-jawed  larvae 
before  pupation.  The  grape-vine-root  borer,  Memythrus  poUstijormis,  looks 
much  like  a  large  Polistes  wasp,  having  a  dark  body  with  two  bright* yellow 


Fig.  556. — Larva  of  peach-tree  borer,  5aKwmo/(/ea  exitiosa.      (After  Slingerland;   natural 

size  and  much  enlarged.) 

narrow  bands  about  the  abdomen;  the  fore  wings  are  brownish  black,  the 
hind  wings  clear;  the  larvae  bore  in  the  roots  of  wild  and  cultivated  grapes 
and  pupate  underground.  The  raspberry-root  borer,  Bemhecia  tnarginata, 
is  also  very  waspish  in  appearance,  with  its  black  body  repeatedly  banded 


wr 

«. 

!^ 

jjimii 

tfc..«>' 

^|fcr 

i 

L 

<*• 

^BUM 

Mi 

1 

\ 

1 

L 

"^^WlHi 

BP 

Fig.  557. — Cocoons  and  empty  pupal  skins  of  the  peach-tree  borer,  Sannmoidea  exitiosa. 
(After  Slingerland;    natural  size.) 

with  yellow  and  transparent  fore  and  hind  wings.  The  eggs  are  laid  on 
raspberry  canes,  and  the  larvae,  first  boring  into  the  cane,  finally  work  down 
into  the  roots.  Squashes  are  often  badly  injured  by  having  their  stems 
tunneled  by  the  larvae  of  the  squash-vine  borer,  Melittia  ceto,  a  Sesian  with 
olive-brown  fore  wings,  clear  hind  wings,  and  black  or  bronze  abdomen, 


392 


The  Moths  and  Butterflies 


marked  with  red  or  orange,  and  with  the  hind  legs  fringed  with  long  hairs, 
orange  on  the  outer  surface  and  black  on  the  inner.  When  full  grown  the 
larvae  leave  the  stems  and  go  into  the  soil  to  cocoon  and  pupate.     The  genus 


Fig.  558. 


Fig.  559. 


Fig.  558. — The  ash-tree  borer,  Trochiliiim  fraxini.     (After  Lugger;    natural  size.) 
Fig.  559. — Sesia  pidipes,  male.     (After  Lugger;    natural  size.) 

Sesia  (Fig.  563)  contains  over  half  (fifty-seven)  of  the  species  in  this  family; 

they  are  found  in  all  parts  of  the  country. 

The  family  Notodontidse,  comprising  the  puss-moths,  handmaid-moths, 

and  prominents,  is  represented  in 
this  country  by  about  ninety-five 
species,  all  of  medium  siz.e,  i.e.,  with 
a  wing  expanse  of  from  ij  to  2 
inches,  and  but  few  of  such  marked 
patterns  as  to  be  particularly  con- 
spicuous or  attractive  to  collectors. 
The  name  "  prominents,"  sometimes 
applied  collectively  to  the  moths  of 
this  family,  is  based  on  the  occur- 
rence in  some  of  them  of  an  angu- 
lated  or  tooth-like  projection  near 
the  middle  of  the  hinder  margin  of 
the  fore  wings.  Probably  the  most 
famiUar  species  in  this  family  are 
the  Datanas,  or  handmaid-moths; 
certainly  their  larvae  are  more  often 
seen  and  are  better  known,  under 
the  names  of  yellow-necked  apple- 
tree  caterpillars  and  walnut  cater- 
pillars, than  the  larvae  of  any  other 

Notodontids.     Sometimes  there  may  be   seen  on  the  trunk  of  an  apple-  or 

other  shade-tree  an  animated  bunch   or  mass  of  hundreds  of  caterpillars, 


Fig.  560. — Venation  of  a  Notodontid,  Noto- 
donta  stragula.  cs,  costal  vein;  sc,  sub- 
costal vein;  r,  radial  vein;  m,  medial 
vein;  c,  cubital  vein;  a,  anal  veins. 
(After  Comstock;    enlarged.) 


The  Moths  and  Butterflies 


393 


reddish  black  with  conspicuous  yellow  longitudinal  stripes,  each  caterpillar 

curiously  jerking  its  body  or  resting  quietly  with  both  head  and  body  tip 

held  up  nearly  at  right  angles  to  the  middle  part  with  its  four  pairs  of  clinging 

prop-legs.     These  are  Datana  larvie,  which 

have  come  down  from  their  feeding  on   the 

leaves  of  the    tree    to    moult.     The  jerking^,,. 

frightens  away  in  some  measure  the  numerous 

parasitic   Tachina    flies    which    are   always 

ready  to  attend  on  a  gathering   of  this  sort 

and  lay  a  few  eggs  where  they  will  do  the 

Tachina  species  the  most  good,  that    is,  on 

the    body   of    these    plump    caterpillars,    so 

that  the  hatching  Tachina  grub  can  burrow  into  this  well-nourished  Ijody 

and  feed  on  its  living  tissues.     When  feeding  in  the  tree-tops,  too,  the  Datana 


Fig.  561. — The  red-humped  cater- 
pillar-moth, CEdemasia  eximia^ 
(After  Packard;  natural  size.) 


Fig.  562. — Larva  of  red-humped  caierpillar-moth,  CEdemasia  eximia.     (After  Packard; 

natural  size.) 

caterpillars  keep  closely  together,  forming  rows  or  files  of  voracious  feeders 
arranged  neatly  across  each  attacked  leaf.  The  common  species  infesting 
the  apple  is  Datana  ministra,  and  the  larvce  have  a  distinguishing  dull  orange 

spot  on  the  back  of  the  first  body-ring 
behind  the  head.  The  eggs,  which  are 
white  and  spherical,  are  laid,  from  70  to 
100  by  each  female,  on  the  leaves,  all 
cemented  well  together  in  neat  patches. 
When  the  larvae  are  full  grown  they 
descend  from  the  tree,  burrow  into  the 
soil  for  two  or  three  inches,  and  change 
to  naked  brown  chrysalids,  which  last 
over  winter,  the  moths  emerging  in  the  following  summer.  The  moth, 
expanding  ih  inches,  is  reddish  or  yellowish  brown,  with  the  fore  wings 
crossed  by  from  three  to  five  darker  brown  lines,  the  outer  margin  and  one 


Fig.  563.  —  Heterocampa      guttivitta. 
(After  Packard;    natural  size.) 


394  The  Moths  and  Butterflies 

or  two  spots  near  the  middle  also  being  darker;  the  hind  wings  are  pale 
yellow  and  not  patterned.  The  species  common  on  walnuts  and  hickories  is 
Datana  angusit,  with  fore  wings  varying  from  chocolate  to  deep  smoky 
brown,  with   transverse  lines  like  those  of   ministra;    the   hind  wings  are 


Fig.  564. — Larva  of  Heterocampa  guttivitta.     (After  Packard;  natural  size.) 

paler  brown.  The  caterpillars  are  black,  with  dirty-white  hairs  and  with 
three  equidistant,  very  narrow,  pale-yellow  or  whitish  stripes  on  each  side 
and  three  yellow  stripes  on  the  under  side;  when  full  grown  it  is  a  little  more 
than  2  inches  long. 

Another  conspicuous  Notodontid  larva  occurring  on  apple-trees  is  a 
greenish-yellow  black-striped  caterpillar  with  a  coral-red  head  and  promi- 
nent hump  on  the  back  of  the  fourth  body-ring.  This  is  the  larva  (Fig.  562) 
of  the  red-humped  caterpillar-moth,  (Edemasia  concinna  (Fig.  561),  a 
darkish-brown  moth  expanding  about  i\  inches,  the  fore  wings  having  a 
darker  brown  spot  near  the  middle,  a  spot  near  each  angle,  and  several 
longitudinal  streaks  along  the  hinder  margin. 

The  puss-moths,  Cerura,  are  readily  distinguishable  by  their  characteristic 
black  and  white  wings,  white  being  the  ground  color,  with  two  broad,  not 
sharply  defined  blackish  bars  across  the  fore  wing,  one  across  the  disk,  the 
other,  often  incomplete  posteriorly,  across  the  apex.  Along  the  outer  margin 
of  each  wing  there  is  a  row  of  distinct  small  black  points.  The  larvae  (Fig. 
793)  of  Cerura  are  extraordinary  creatures:  short,  thick,  naked  body,  tapering 
behind  to  a  kind  of  forked  tail  which  is  held  up  at  an  angle  with  the  rest 
of  the  body.  This  tail,  which  is  an  organ  of  defence,  consists  of  two  tubes, 
within  each  of  which  is  concealed  a  long  orange-colored  extensile  thread 
which  can  be  thrust  out  and  drawn  in  at  will.  When  disturbed,  the  puss- 
moth  caterpillar  thrusts  out  these  vivid  tails,  waving  them  threateningly, 
at  the  same  time  giving  off  a  strong  odor.  It  also  telescopes  its  head  and 
front  two  thoracic  segments  into  the  large,  humped,  third  segment,  which  is 
so  shaped  and  marked  as  to  suggest  some  formidable  large-eyed  creature 
quite  unlike  a  soft-bodied  toothsome  caterpillar.  With  little  doubt  this 
elaborate  terrifying  but  actually  harmless  equipment  avails  to  frighten  off 
many  of  Cerura's  enemies.  The  larva  of  a  common  puss-moth  species 
feeds  on  wild  cherry.  When  ready  to  pupate  the  caterpillars  gnaw  out  a 
shallow  cavity  or  depression  in  the  wood  which  they  lie  in  and  over  which 
they  spin  an  oval  silken  net  mixed  with  particles  of  wood,  which  makes  it 
almost  indistinguishable  from  the  rest  of  the  wood  surface.     These  moths 


The  Moths  and  Butterflies 


395 


seem  to  carry  very  far  expedients  of  Nature  for  protection  by  deceit.  Other 
common  members  of  the  family  are  the  several  species  of  Schizura,  moths 
strongly  resembling  owlet-moths  (Noctuidas)  with  their  brown  and  gray 
and  gray  and  blackish  finely  variegated  fore  wings  and  unmarked  silky  white 
wings.  Their  brown  or  greenish  larvae,  which  feed  on  fruit-trees,  forest 
trees,  small  fruits,  and  other  shrubby  plants,  are  distinguished  by  having 
a  prominent  horn  or  spined  tubercle  on  the  fourth  body-ring  behind  the 
head.  They  are  said  to  eat  out  a  notch  about  the  size  of  the  body,  in  the  edge 
of  a  leaf,  fitting  themselves  along  this  notch,  so  that  the  prominent  tubercle 
and  other  irregularities  of  the  body  seem  to  simulate  the  rounded  edge  of 
the  leaf;  they  are  thus  well  concealed.  The  moths,  too,  are  much  given 
to  dissimulation.     Each  moth  rests  on  the  trunk  or  branches  of  the  tree, 


Fig.  565. — Canker-worms,  larvae  of  a  geometrid  moth.     (After  Slingerland;  natural  size.) 


head  downward,  with  wings  closely  folded  around  the  body  and  legs  all 
drawn  together,  the  dull-gray  tone  of  the  wings  with  their  bits  of  lichen- 
green  and  whitish  color  giving  the  whole  a  marvelous  resemblance  to  a  bit 
of  rough  weathered  bark. 

Familiar  to  all  observers,  although  certainly  not  very  often  seen  and 
rarely  found  in  large  numbers,  are  the  inchworms,  spanworms,  or  loopers 


39^ 


The  Moths  and  Butterflies 


Fig.  566. — Lime-tree  inch-worm,  larva 
of  the  geometrid  moth,  Hibernia 
tiliaria.  (After  Pettit;  twice  natural 
size.) 


/v 


as  they  are  variously  called,  which  are  the  larvae  (caterpillars)  (Fig.  565) 
of  the  moths  of  the  superfamily  Geometrina  (earth-measurers).  These 
three  common  names  as  well  as  the  scientific  one  refer  to  the  peculiar  mode 
of  locomotion  affected  by  all  the  Geometrina.  Each  loop  or  step  is  made  by 
the  bringing  forward  of  the  caudal  extremity  of  the  body  quite  to  the  thoracic 
feet,  the  portion  of  flexible  body  between 
bending  up  and  out  of  the  way  each  time 
during  the  process.  The  reason  for  it 
all  will  be  understood  when  the  inch- 
worm  is  examined.  It  differs  from  other 
lepidopterous  larvae  in  lacking  the  front 
three  of  the  four  pairs  of  prop-legs 
normally  belonging  to  the  middle  part 
of    the    body,  which    is    thus    rendered 

helpless  in  walking,  and  the  curious  looping  gait  is  the  outcome  of  the  pos- 
session by  a  long  slender  flexible  body  of  only  anterior  and  posterior  locomotory 
organs  (Fig.  566).     Why  inchworms  are  not  more  often  seen,  although  there 

are  hosts  of  different  kinds  of  them  and  they 
are  well  distributed  and  common  all  over  the 
country,  is  due  to  their  habit  of  "going 
stiff"  when  disturbed,  clinging  by  the  hinder 
two  pairs  of  legs  to  the  twig  or  leaf  and 
holding  the  rest  of  the  body  motionless  and 
rigid  at  an  angle  with  the  support.  As  the 
body  is  always  protectively  colored  and 
marked,  so  as  to  harmonize  thoroughly  with 
the  habitual  surroundings  many  an  inch- 
worm  may  be  seen  but  not  distinguished 
from  the  leaf  or  branch  on  which  it  rests. 
Indeed,  many  of  the  inchworms  are  amaz- 
ingly like  a  short  or  broken  twig,  with  buds 
or  leaf  scars  and  lined  or  scaly  bark,  a  very 
effective  case  of  protective  resemblance. 

The  geometer-moths,  of  which  we  have 
800  species  in  this  country,  while  of  course 
presenting  a  great  variety  of  coloration  and 
pattern  yet  possess  a  likeness  of  general 
appearance  due  mostly  to  the  slenderness  of 
body  compared  with  the  broadness  of  wings,  the  impression  of  fragility  or  thin- 
ness of  wings  due  to  the  unusually  fineness  of  the  covering  scales,  and  the  deli- 
cate and  quiet  coloration  and  patterning,  which  indicate  their  identity  pretty 
effectively.     Some  are  small,  i.e.,  less  than  i  inch  expanse,  and  a  few  large, 


Fig.  567. — -Venation  of  a  geometrid, 
Dyspepteris  abortivaria.  cs,  cos- 
tal vein;  sc,  subcostal  vein;  r, 
radial  vein;  m,  medial  vein; 
c,  cubital  vein;  a,  anal  veins. 
(After  Comstock;    enlarged.) 


The  Moths  and  Butterflies  397 

i.e.,  over  2  inches  expanse,  but  most  are  of  medium  size,  with  white,  deli- 
cate green,  soft  yellowish,  brownish,  grayish,  and  blackish  as  predominating 
color  tones,  and  delicate  wavy  or  zigzagging  transverse  lines,  or  point-like 
spots  as  characteristic  pattern  markings.  The  superfamily  is  divided  into 
five  famiUes  based  on  venational  characters  rather  confusing  and  appar- 
ently not  surely  indicative  of  natural  relationships.     We  may  content  our- 


5 


Fig.  568. — Male  and  IriiKilc  lime-tree  canker-moths,  Hibernia  tiliaria.     (After  Jordan 
and  Kellogg;    twice  natural  size.) 

selves  with  brief  reference  to  some  of  the  more  interesting,  beautiful,  or  eco- 
nomically important  species. 

The  best-known  Geometrids  of  economic  importance  are  the  canker- 
worms  (Fig.  565),  two  species  in  particular,  known  as  the  spring  canker- 
worm  (Paleacrita  vernata)  and  the  fall  canker-worm  {Anisopteryx  pometaria), 
being  responsible  for  much  damage  to  orchards,  especially  apple-orchards. 
The  females  of  the  canker-worm  moths  are  wingless  and  so  have  to  climb 
the  trees  to  lay  their  eggs  on  the  branches  and  twigs. 
This  fact  naturally  suggests  the  most  effective  remedy 
for  them,  namely,  banding  the  trees  with  tar  (mixed 
with  oil  to  prevent  its  drying)  so  as  to  make  effective 
barriers  against  them  as  they  crawl  upward.     Printers'  „        ^        r^    .  ..    • 

°  y  r  YlG.  50Q. — Dyspepterts 

ink,  refuse  sorghum,  or  any  slow-drying  varnish  is  abortivaria.  (After 
equally  effective.  From  the  eggs  laid  in  the  spring  by  Lugger;  natural 
Paleacrita  and  in  the  fall  by  Anisopteryx  hatch  active 
little  "loopers"  which  feed  voraciously  in  the  foliage.  The  eggs  of  the  fall 
canker-worm  do  not  hatch  until  the  following  spring,  just  when  the  young 
apple-leaves  begin  to  unfold.  The  full-grown  canker-worms  are  about  i 
inch  long,  greenish  brown  and  striped  longitudinally  with  pale  yellow. 
Some  of  these  stripes  are  broad  on  the  fall  canker-worm;  all  are  narrow 
on  the  other  species.  When  full  grown  the  larvae  crawl  down  the  tree  to  the 
ground,  burrow  into  it  and  pupate  in  a  thin  silver  cocoon.  The  males  of  both 
species  are  winged  delicate  moths;  Paleacrita  has  pale  ash-colored  or  brownish- 
gray,  silky,  almost  transparent  fore  wings  with  four  or  five  broken  transverse 


398 


The  Moths  and  Butterflies 


dark    lines;   Anisopteryx   has   glossy   brownish   fore   wings   crossed   by  two 
irregular  whitish  bands. 

Among  the  Geometrids  are  numerous  species  whose  wings  are  green, 
the  shades  varying,  but  usually  with  a  strong  admixture  of  whitish  and  also 


Fig.  570.  .  Fig. 571. 

Fig.   570. — The    pepper-and-salt    currant-moth,    Eubyia    cognataria.      (After    Packard; 

natural  size.) 
Yic.    ;;7i. — Phigalia  strigataria,  the  iemale  wingless.     (After  Lugger;    natural  size.) 

usually  barred  more  or  less  distinctly  with  narrow  or  broader  whitish  lines. 
Geometra  iridaria  is  such  a  species  common  in  the  East  in  which  the  green 
is  very  light  in  tone;   Dyspepteris  abortivaria  (Fig.  569)  is  bluish  green  and 


Fig.  572.                                            Fig.  573.  Fig.  574. 

Fig.  572. — The  large  blue-striped  looper,  Biston  ypsilon.  (After  Forbes;    natural  size.) 

Fig.  573. — The    common    Cymatophora,    Cymatophora  pampinaria.     (After    Lugger; 

natural  size.) 

Fig.   S74. — The  plum-geometer,  Eumacaria  hrunneraria.  (After  Lugger;    natural  size.) 

has  a  grape-feeding  larva.  The  raspberry  geometer,  Synchlora  glaucaria, 
has  delicate  pale-green  wings  with  two  transverse  whitish  lines;  its  larvse 
feed  in  the  fruit  and  leaves  of  raspberries  and  blackberries  and  cover  over 

the  body  with  bits  of  vegetable  matter  like  minute 
pieces  of  flowers,  etc.,  until  it  seems  to  be  only  a 
tiny  heap  of  debris.  The  snow-white  Eugonia, 
Ennonos  suhsignarius,  is  pure  white,  expanding 
an  inch  and  a  half;  its  larvae  feed  often  de- 
structively on  the  foliage  of  elms,  lindens,  and 
apple-trees.  Angerona  crocotaria  (Fig.  576)  is 
a  beautiful  sulphur  -  yellow  Geometrid,  ex- 
panding i\  inches,  with  a  number  of  irregular  pinkish-brown  blotches 
on  the  wings;    its  yellowish-green    larvae   feed   on   currants,   gooseberries. 


Fig.  575. — The  currant  fruit- 
worm  moth,  Enpithecia  in- 
trrruptofasciata.  (After 
Lugger;  natural  size.) 


The  Moths  and  Butterflies 


399 


and  strawberries,  both  wild  and  cultivated.  Calocalpe  undulata  (Fig.  578), 
the  scallop-shell  moth,  has  pale  yellowish-brown  wings  crossed  by  many 
fine  zigzag  darker  lines  close  together;  its  larva?  feed  on  wild  cherry  and 
live  gregariously  inside  of  a  nest  formed  of  leaves  tied  together  by  silken 
threads.  A  very  common  little  moth  in  meadows  and  gardens  in  summer 
and    fall    is    the    chickweed-geometer,  HcBmatopis   grataria,  with    reddish- 


FiG.  576.  Fig.  577.  Fig.  578. 

Fig.  576. — The  currant-angerona,  Angerona  crocataria.  (After  Lugger;  natural  size.) 
Fig.  577. — The  currant-endropia,  Endropia  armaiaria.  (After  Lugger;  natural  size.) 
Fig.    578. — The  scallop-shell  geometer,  Ca/oca//)e  M«(fj</ato.     (After  Lugger;  natural  size.) 

yellow  wings  and  two  transverse  bands  and  the  outer  margins  pinkish 
The  chain-dotted  geometer,  Caterva  catenaria,  expanding  ij  inches,  with 
white  wings  dotted  with  fine  black  points  arranged  in  two  lines  and  with 
a  few  extra  ones,  appears  sometimes,  according  to  Lugger,  in  such  very 
great  numbers  as  to  look  like  a  snow-storm;  its  larvae  are  pale  straw-yellow 
with  two  fine  lines  on  the  back  and  two  on  each  side  interrupted  by  two 


Fig.  579. — The  diverse-lined  geometer,  Petrophora  diver silineata.     (After  Lugger; 

natural  size.) 

large  black  dots,  a  pair  on  each  segment;    it  feeds  on  hazel,  blackberry, 
raspberry,  and  other  plants. 

A  great  host  of  somber-colored  moths,  blackish,  grayish,  or  brownish, 
with  no  conspicuous  markings  and  only  rarely  any  bright  colors,  compose 
for  the  most  part  the  family  Noctuidse,  the  largest  of  all  the  families  of  moths. 
Twenty-one  hundred  North  American  species — three  times  as  many  as 
there  are  North  American  species  of  birds — belong  to  the  single  family 
Noctuidae,  and  for  the  most  part  these  two  thousand  mixed  species  must  be 
as  one  to  the  general  collector  and  amateur.  Few  professional  entomologists, 
indeed,  lay  claim  to  a  systematic  knowledge  of  the  group,  or  even  care  to 
give  to  it  the  time  necessary  to  acquire    such  a  knowledge.     Some  of  the 


400 


The  Moths  and  Butterflies 


Noctuids  have  come  into  prominence  because  of  the  destructive  vegetable- 
feeding  habits  of  their  larva' ;  such  are  the  cutworm-moths,  the  army- 
worm  moths,  the  cotton-worm  moths,  and  others,  and  these  species  are 
so  often  described  and  pictured  that  they  are  fairly  well  known.  Other 
small  groups,  of  which  the  interesting  Catocalas,  the  red  and  yellow  under- 
wings  (Fig.  580),  are  the  most  conspicuous,  have  attracted  the  attention 
of  collectors  because  of  particular  habits  or  patterns,  and  these  are  fairly 


Fig.  580. — A  group  of  red  and  yellow  underwings;  upper  moth,  Catocala  palceogiima; 
lower  left-hand  corner,  Catocala  iiltronia;  lower  right-hand  corner,  Catocala  grymea. 
(After  Lugger;    natural  size.) 


well  known.  Few  moth-collectors  but  have  "sugared"  for  Catocalas, 
those  large  night-flyers,  somber  of  fore  wing  but  brilliant  of  hind  wing, 
that  can  be  so  readily  attracted  and  taken  by  a  bait  of  molasses  and  stale 
beer  smeared  in  patches  on  the  trunks  of  trees  in  summer-time.  The  fore 
wings  harmonize  in  color,  shades,  and  pattern  so  thoroughly  with  the  bark 
that  when  the  Catocala  rests,  as  it  does  during  the  daytime,  on  tree-trunks 
with  its  brilliant  hind  wings,  strikingly  banded  with  red,  yellow,  white,  or 
black,  covered  by  the  fore  wings,  it  is  simply  indistinguishable.  The 
Catocala  larvae  are  curious  creatures,  with  body  thick  in  the  middle  and 


The  Moths  and  Butterflies 


401 


tapering  towards  both  ends.  The  lar\ie  of  Catocala  nltronia  (Fig.  581) 
feed  on  plum-tree  leaves;  tlicy  arc  about  ij  inches  long,  grayish  brown, 
with  two  or  four  small  reddish  tubercles  on  each  body-segment,  a  small 
fleshy  horn  on  the  back  of  the  ninth  segment  and  on  the  back  of  the  twelfth 
segment  a  low  fleshy  ridge  tinted  behind  with  reddish  brown.  It  descends 
to  the  ground  when  ready  to  pupate,  making  a  flimsy  cocoon  of  silk  under 
a  dead  leaf  or  chip.  The  pupa  inside  the  cocoon  is  covered  with  a  bluish 
flour-like  dust  or  "bloom."  The  moth  has  the  forewings  rich  amber  with 
a  broad   indefinite   ashy  band  along  the  middle  and  several  brown  and 


Fig.  581. — The  plum-tree  Catocala,  Catocala  iiUronia,  moth  and  larva. 
(After  Lugger;  natural  size.) 

white  transverse  lines;  the  hind  wings  are  deep  red  with  a  wide  black 
band  along  the  outer  margin  and  a  narrower  one  across  the  middle.  The 
eggs  are  laid  in  cracks  of  the  bark  in  slimmer.  Catocala  grynea  (Fig.  580), 
with  grayish  brown  forewings  marked  with  zigzag  lines  of  rich  brown  and 
gray  short  dark-brown  streaks  on  the  front  margin  and  with  hind  wings 
reddish  yellow  crossed  by  two  wavy  black  bands,  is  called  the  apple-tree 
Catocala,  because  the  ashen-brown  caterpillar  feeds  on  apple-leaves.  The 
two  front  pairs  of  abdominal  prop-legs  of  all  the  Catocala  caterpillars  are 
much  smaller  than  the  hinder  two  pairs,  hence  the  caterpillar  has  a  sort  of 
looping  gait  like  that  of  the  Geometrid  larvae,  the  inchworms.  Catocala 
relicta  has  the  fore  wings  grayish  white  with  several  indefinite  transverse 
black  bands,  and  the  hind  wings  black  with  one  curving  white  band. 
Catocala  epione  has  blackish-brown  fore  wings  with  wavy  narrow  black  and 
lighter  brown  transverse  lines  with  black  hind  wings  narrowly  rr^argined 
with  white. 

The  largest  and  most  interesting  Noctuid,  and  indeed  one  of  the  largest 
of  all  the  moths,  is  the  curious  rare  species  Erebus  odora,  called  the  black 
witch;   it  expands  6  inches  and  has  both  wings  blackish  brown  with  many 


40: 


The  Moths  and  Butterflies 


indefinite  wavy  lines  of  black  and  of  lighter  brown;  in  the  hinder  angle 
of  the  hind  wings  are  two  incomplete  eye-spots  bounded  in  front  by  a  curv- 
ing velvety  black  line,  and  on  each  fore  wing  is  a  single  irregular  eye-spot 
near  the  front  margin. 

"Cutworm"  is  the  name  applied  to  the  smooth,  "greasy,"  plump  cater- 
pillars of  numerous  species  (representing  several  genera)  of  Noctuids.  The 
greasy  cutworm,  dull  blackish  brown  with  pale  longitudinal  Unes  attacks 
all  sorts  of  garden  products  and  other  low-growing  plants;    it  is  the  larva 


Fig.  582. — Green-fruit  worms,   Xylina  grotci,   at  left,   and  Xylina  antennata  at  right. 
(Photograph  by  Shngerland;    natural  size.) 

of  A  gratis  ypsilon,  with  brownish-gray  fore  wings  bearing  an  ypsilon- 
shaped  mark,  the  hind  wings  being  silky  white.  The  climbing  cutworm, 
Carneades  scandens,  an  active  climber  and  great  enemy  of  nurseries  and 
orchards,  is  light  yellowish  gray  with  a  dark  line  along  the  back  and  fainter 
ones  along  the  sides;  the  moth  has  light  bluish-gray  fore  wings  with  darker 
markings  and  pearly-white  hind  wings.  Almost  all  the  cutworms  hide 
in  cracks  in  the  ground  by  day,  feeding  during  the  night;  they  will  often 
cut  off  young  plants  just  at  the  ground,  or  will  ascend  tall  trees  and  feed 
on  the  buds  and  young  leaves.  When  ready  to  pupate  they  burrow  into 
the  soil  and  the  moths  issue  in  midsummer. 

The.  members  of  the  large  genus  Plusia  (PI.  VIII,  Fig.  7),  including  some 
of  the  commonest  Noctuids,  are  recognizable  by  a  small  silvery  comma-shaped 
spot  on  the  disk  of  each  fore  wing.  Another  large  genus  is  that  of  Cucul- 
lia,  the  hooded  owlets,  in  which  the  thorax  bears  a  prominent  tuft  of  scales 
and    the   fore    wings    are    marked   with    irregular    blackish    dashes.     The 


The  Moths  and  Butterflies 


403 


Fig.  583. — Army-worms,  larvae  of  Leucania  unipuncta,  on  corn.     (Photograph  by 
Slingerland;  natural  size.) 


404 


The  Moths  and  Butterflies 


dagger-moth  Acronycta  (Figs.  586  and  587),  so  called  from  the  rather  uncer- 
tain small  black  dagger-like  markings  of  the  fore  wings,  have  the  larva  in 
some  species  covered  with  long  colored  stiff  hairs;    the  familiar  caterpillar 

of  A.  americana  is  densely  clothed  with 
yellow  hairs,  besides  bearing  a  pair  of 
long  black  pencils  on  the  first  abdominal 
segment,  another  pair  on  the  third,  and 
a  single  pencil  on  the  eighth.  It  feeds  on 
the  leaves  of  elm,  maple,  and  other  trees, 
and  when  at  rest  curls  sidewise  on  a  leaf. 
The  army- worm  (Fig.  583),  a  black, 
yellow,  and  green  striped  caterpillar 
that  occurs  over  nearly  all  the  country 
and  often  appears  in  enormous  numbers, 
causing  great  losses  to  grain-fields,  is 
the  larva  of  a  dull-brown  moth,  Leu- 
cania   unipuncta,  marked   in    the   center 

costal  vein-^W  °^  ^^^'^   ^°^^   ^^"S    ^^^^  ^  distinct  white 
r,  radial  vein;    m,  spot.      Perhaps  as   severe   a  sufferer  as 

medial  vein;    c    cubital  vein;   a,  anal  ^ny  other  field  product    from  the    attacks 

veins.     (After  Comstock;  enlarged.)  ■'  ^ 

of  Noctuid  larvae  is  cotton.  The  cotton- 
worm,  Aletiaargillacea,  feeds  on  the  foliage  of  the  cotton-plants  and  the  cotton 
boll-worm,  Heliothis  armigera,  attacks  the  cotton  pods  or  bolls.  These  two 
caterpillars  cause  losses  to  the  cotton-growing  states  of  millions  of  doUars- 


FiG.  584.  —  Venation 
A  gratis  ypsilon.  cs, 
subcostal    vein 


^NA  \i  I  ■  'iiiML  ■'!> 


.  ^«»- ■!>.•••  ^-*»4#  v#"%i*  ■-*  ■*'n . 


Fig.  585.  Fig.  586. 

Fig.  585. — Larvae   of   the    gray    dagger-moth,    Acronycta    occidentalis.     (After    Lugger;. 

natural  size.) 
Fig.  586. — Gray   dagger-moth,    Acronycta   occidentalis.     (After   Lugger;     natural   size.) 

every  year.  The  cotton  boll-worm  is  more  or  less  familiar  in  states  farther 
north,  under  the  name  of  corn-worm,  where  it  is  found  feeding  on  ears  of 
green  corn  and  on  tomatoes.  It  is  a  naked,  greenish-brown,  dark -striped 
caterpillar.  The  moth  has  pale  clay-yellow  fore  wings  with  a  greenish  tint, 
the  hind  wings  paler. 

Among  the  most  conspicuous  of  all  the  caterpillars  are  the  not  unfamiliar 
larvae  of  the  tussock-moths,  Lymantriidae,  one  common  species  infesting  our 


PLATE  VI. 

MOTHS. 

i  =  Catocala  parta. 
2=Basilona  imperialis. 
3  =  Apanresis  virgo. 
4=Pseudohazis  eglanterina. 
5  =  Automeris  io. 


PLATE   VI 


Mary  Welhnan^  del. 


The  Moths  and  Butterflies 


405 


Fig.  587. — The  raspberry  dagger- 
moth,  Acronycta  imprcssa.  (After 
Lugger;   natural  size.) 


shade-trees  in  town  and  country  and  another,  less  common,  attacking  orchards 
and  forest-trees.  The  caterpillars  (Fig.  588)  of  Notolophus  leucostigma , 
the  white-marked  tussock-moth,  which  is  the  shade-tree  species,  are  about 
i\  inches  long,  very  hairy,  bright  yellow  with  a  blackish  stripe  along  the  back 
and  one  along  each  side,  but  chiefly  conspicuous  by  a  series  of  four  cream- 
colored  dense  tufts  of  vertical  hairs  on  the  back,  three  long  black  hair  pen- 
cils, two  on  the  front  part  and  one  on  the 
hind  part  of  the  body,  and  by  the  coral-red 
head  and  similarly  colored  two  small  pro- 
tuberances on  the  sixth  and  seventh  abdom- 
inal segment  which  are  scent-organs  used 
to  repel  enemies.  When  full-grown  these 
caterpillars  pull  the  hairs  from  their  body 
and  mixing  them  with  some  silk  make  a 
grayish  cocoon  on  the  tree-trunks.  The  fe- 
male moth  is  wingless,  light  gray  in  color, 
and  unusually  long-legged  for  a  moth;  when  issued  she  simply  crawls  out  of  the 
cocoon  and  lays  her  300  to  500  eggs  covered  by  a  frothy-looking  but  firm  sub- 
stance in  a  grayish  mass  on  the  outside  of  it.  The  males  are  ashy  gray  and 
have  broad  short  wings,  expanding  i^  inches,  the  fore  wings  with  darker  wavy 
transverse  bands,  a  small  black  spot  near  the  tip,  an  obhque  blackish  stripe 
beyond  it,  and  a  minute  white  crescent  near  the  outer  hinder  angle.     The 

antennas  are  feathery,  and  the 
fore  legs  tufted  with  hairs.  The 
best  remedy  for  these  pests  is 
to  gather  the  egg-masses  in  the 
winter  and  put  them  into  a  box 
with  its  top  covered  by  mosquito- 
netting.  In  the  spring  the  moths 
and  the  egg  parasites  which  are 
numerous  will  hatch;  the  minute  parasites  will  escape  through  the  netting 
to  go  on  with  their  good  work,  while  the  moths  will  be  retained  in  the  box 
and  may  be  killed. 

The  orchard  and  fruit-tree  species,  Parorgyia  parallela,  the  parallel- 
lined  tussock-moth,  is  winged  in  both  sexes,  the  moths  being  dark  gray  with 
darker-colored  wavy  lines  and  spots.  The  caterpillars  are  gray  with  lon- 
gitudinal black  stripes;  short  black  tussocks  are  found  on  the  back  of  seg- 
ments 4  to  7,  a  pair  of  long  black  pencils  is  at  each  end  of  the  body,  and  on 
the  back  of  each  of  segments  9  and  10  is  a  small  pale-yellow  scent-cup. 
The  head  is  shining  black.  It  feeds  especially  on  plum-,  crabapple-,  and 
oak-trees. 

The  most  notorious  member  of  the  Noctuidae  is  the  gypsy-moth,  Ocneria 


Fig,  588. — Larva   of    the   tussock-moth,   Noto- 
lophus leucostigma.     (After  Felt,  natural  size.) 


4o6 


The  Moths  and  Butterflies 


dispar,  a  European  species  brought  to  Massachusetts  in  1868,  and  from 
1890  to  1900  fought  at  the  pubHc  expense.  A  gentleman  living  in  Med- 
ford,  a  town  of  Massachusetts,  imported  a  number  of  different  kinds  of  Euro- 
pean silk-spinning  caterpillars  in  an  attempt  to  find  some  species  which 
might  be  bred  in  this  country  in  place  of  the  mulberry  silkworm  {Bombyx 
mori).  Some  of  the  moths  escaped  from  his  breeding-cages,  and  among 
them  some  gypsy-moths.  In  a  very  few  years  the  species  had  increased  to 
such  numbers  and  spread  throughout  such  an  extent  of  woods  that  it  seri- 
ously threatened  the  destruction  of  all  the  forest-  and  shade-trees  in  north- 
eastern Massachusetts.  By  189 1  it  was  causing  great  injury  to  forest-trees 
over  200  square  miles.  So  far  it  has  been  confined  because  of  the  whole- 
sale operations  against  it.  The  State  has  employed  as  many  as  570  men 
at  a  time  in  spraying,  egg-collecting,  trunk-banding,  etc.,  in  the  great  fight 


Fig.  589. — The  California  oak-worm  moth,  Phryganidia  californica.  A,  eggs  on  leaf; 
B,  just-hatched  larva;  C,  full-grown  larva;  D,  pupa,  or  chrysahd;  E,  moth;  F,  Pimpla 
behrendsii,  parasite  of  the  larva.  {B,  much  enlarged;  D  and  F,  twice  natural  size; 
others  natural  size.) 


against  the  pest  and  up  to  1900  had  expended  over  a  million  dollars  in  the 
struggle.  The  caterpillar  when  full  grown  is  i^  inches  long,  creamy  white, 
thickly  sprinkled  with  black,  with  dorsal  and  lateral  tufts  of  long  black  and 
yellowish  hairs.  The  cocoon  is  very  slight,  merely  a  few  silky  threads.  The 
male  moths,  expanding  i|  to  2  inches,  are  brownish  yellow  with  smoky  fore 
wings  bearing  darker  irregular  transverse  lines  and  pale  hind  wings  with 
darker  outer  margins.  The  females  are  large,  expanding  2^  inches,  and 
creamy  white  in  color,  with  irregular  transverse  gray  or  blackish  hnes. 


The  Moths  and  Buttertiies  407 

In  California  is  found  a  pretty  pale-brownish  moth  that  flutters  weakly 
about  the  live-oak  trees  in  early  summer  and  late  autumn,  which  has  the 
distinction  of  being  the  only  North  American  species  in  the  family  Dioptida:. 
The  larvs  of  this  moth  feed  chiefly  on  the  leaves  of  the  live-oaks  and  white 
oaks  in  the  California  valleys  and  the  species  may  be  called  the  live-oak 
moth,  Phryganidia  calijornica  (Fig.  589).  The  moths  expand  about  i  inch 
and  are  uniformly  pale  brownish,  with  thinly  scaled  and  hence  almost  trans- 
lucent wings.  The  male  has  a  small  yellowish-white  ill-defined  blotch  on 
the  center  of  each  fore  wing.  The  eggs  are  laid  by  the  early  summer  brood 
of  moths  on  the  under  side  of  the  leaves  of  the  oaks  and  the  naked  light- 
yellowish  black-striped  larvae  feed  until  October  ist  on  the  tough  leaves. 
Then  they  crawl  down  to  the  tree-trunks  or  to  near-by  fences  or  logs  and 
change  to  a  naked  greenish-white  or  yellowish  chrysalid  with  many  black 
lines  and  blotches.  The  moths  issue  in  from  ten  to  twelve  days  after  pupa- 
tion and  lay  their  eggs  again  on  the  oak-leaves.  But  here  is  a  curious  fact. 
All  the  eggs  laid  on  white-oak  leaves  by  these  autumn  moths  are  doomed 
to  death  because  just  at  the  hatching-time  the  white-oak  leaves  fall  and  dry. 
The  live-oak  retains  its  leaves  all  winter  and  the  larvae  hatched  on  them 
feed  and  grow  slowly  through  the  winter,  pupating  in  May  and  issuing  as 
moths  about  June  ist.  Thus  each  year  about  one-fourth  of  the  eggs  laid 
by  this  species  are  wasted.  The  larvae  from  the  eggs  laid  on  the  white  oaks 
in  the  spring  live  because  they  have  white-oak  leaves  all  summer  to  feed 
on,  but  those  of  the  fall  brood  which  hatch  on  the  white  oaks  all  die.  In 
some  seasons  this  insect  is  so  abundant  as  to  defoliate  the  oak-trees  in  cer- 
tain localities  twice  during  the  year,  but  whenever  the  caterpillars  get  so 
numerous  a  certain  small  slender  ichneumon-fly,  Pimpla  behrendsii,  which 
lives  parasitically  on  them  becomes  also  very  abundant  (there  being  plenty 
of  food  for  its  young)  and  soon  checks  the  increase  of  the  moth.  Out  of 
144  chrysaHds  of  the  moth  which  I  once  gathered  but  11  moths  issued, 
99  of  the  chrysalids  giving  forth  ichneumon-flies  and  the  rest  dying  from 
other  causes.  I  have  found  the  caterpiUar  most  abundant  on  the  live-oaks 
{Q.  agrijolia),  but  it  occurs  also  on  Q.  lobala,  Q.  kelloggii,  Q.  diimosa,  and 
Q.  doiiglassi. 

A  family  represented  in  this  country  by  only  four  species  is  the  Peri- 
copidae.  Three  of  these  species  are  found  only  in  the  western  states,  the 
fourth  in  Florida.  The  single  species  of  the  four  at  all  familiar  to  collectors 
is  the  beautiful  and  abundant  Gnophala  latipennis,  with  its  two  or  three 
varieties.  This  moth  expands  about  2  inches  and  is  black,  with  two 
large  white  blotches  on  the  fore  wing,  each  blotch  subdivided  by  the  black 
veins  running  through  it  and  single  large  blotch  on  the  hind  wing.  A 
variety  common  in  California  has  the  blotches  smaller  and  pale  yellowish. 

The  wood-nymph  moths,  Agaristidae,  of  which  about  two  dozen  species 


4o8 


The  Moths  and  Butterflies 


are  found  in  North  America,  include  a  few  strikingly  patterned  moths  not  at 
all  uncommon.  The  moth  known  as  the  eight-spotted  forester,  Alypia  odo- 
maciilata  (PI.  VIII,  Fig.  5;  also  Fig.  590),  is  common  in  the  Atlantic  states; 


Fig.  590. — Three  eight-spotted  forest-moths,  Alypia  8-maculala,  and  one  beautiful  wood- 
nymph,    Eudryas  grata   (the   lowest).     (After  Lugger;  natural  size.) 


it  expands  about  i^  inches,  has  deep  blue-black  wings,  with  two  large  sub- 
circular  whitish-yellow  spots  on  each  wing,  the  spot  nearest  the  base  on 
the  hind  wing  being  much  larger  than  the  outer  one.  The  patagia  (shoulder- 
lappets)   are  often  yellow  and  the  legs  marked  with  orange.     The  larvae, 


The  Moths  and  Butterflies  409 

which  are  light  brown  with  many  fine  black  lines  and  one  broad  orange 
band  across  each  segment  and  head  and  cervical  shield  deep  orange  with 
black  dots,  feed  on  the  V^irginia  creeper,  sometimes  on  the  grape,  and  often 
are  so  abundant  as  to  injure  the  plants  seriously.  The  caterpillar  is  nearly 
i^  inches  long  when  full-grown,  and  burrows  into  soft  or  rotten  wood  to 
pupate,  or  failing  this  pupates  on  or  just  below  the  surface  of  the  ground. 

The  beautiful  wood-nymph,  Eudryas  grata  (Fig.  590)  (classed  by 
some  entomologists  with  the  Noctuidse),  is  very  different  in  color  and 
pattern,  having  milk-white  fore  wings  broadly  bordered  and  marked  with 
brownish  purple  and  with  two  indistinct  brownish  spots  in  the  center. 
The  under  surface  of  these  wings  is  reddish  yellow.  The  hind  wings  are 
yellow  with  a  pale  purplish-brown  border.  The  head  is  black  and  there 
is  a  wide  black  stripe  along  the  back  of  the  thorax,  breaking  up  into  a 
series  of  spots  along  the  abdomen.  The  caterpillar  is  much  like  that  of 
the  eight-spotted  forester  and  feeds  on  the  same  plants.  "The  moth,  which 
is  active  at  night  and  sometimes  attracted  to  electric  lights  in  large  numbers, 
is  very  often  discovered  during  the  day  upon  the  surface  of  the  leaves  of  its 
food-plants.  Its  closed  wings  form  a  steep  roof  over  its  back,  and  its  four 
legs,  which  have  a  curious  muft'-like  tuft  of  white  hairs,  are  protruded  and 
give  the  insect  a  very  peculiar  appearance." 

The  grape-vine  Epimenis,  Psychomorpha  epimenis,  is  a  small  velvety 
black  Agaristid  moth  with  a  broad,  irregularly  lunate,  white  patch  across 
the  outer  third  of  the  fore  wing  and  a  somewhat  larger  and  more  regular 
patch  of  orange-red  or  brick-red  on  the  hind  wings.  Its  bluish  caterpillar 
feeds  on  grape-leaves. 

Delicate  and  pretty  are  the  little  footman-moths,  Lithosiidae,  in  their 
liveries  of  drab  or  slate,  yellow  or  scarlet,  and  with  their  slender  bodies 
and  trimly  narrow  fore  wings.  The  larvae  of  but  few  species  are  known; 
they  mostly  feed  on  lichens  and  have  the  body  covered  with  short  stiff 
hairs.  Because  these  caterpillars  are  not  injurious  but  little  attention 
has  been  given  to  the  life-history  of  the  footman-moths,  and  the  amateur 
has  here  an  opportunity  to  add  to  our  knowledge  of  insects  in  an  order 
popularly  supposed  to  be  pretty  well  "worked  out." 

The  moths  themselves  although  few  in  number  of  species  are  well  dis- 
tributed over  the  country,  although  the  southwestern  and  Pacific  states 
have  really  more  than  their  share.  Two  common  eastern  species  are 
the  striped  footman,  Hypoprepia  miniata,  and  the  painted  footman, 
H.  juscosa,  each  expanding  about  i  inch.  The  first  is  brick-scarlet,  with 
two  longitudinal  broad  plumbeous  bars  and  the  distal  half  of  a  third  on 
the  fore  wing  and  a  broad  outer  slaty  border  on  the  hind  wings.  The 
latter  has  almost  the  same  pattern,  but  the  ground  color  is  distinctly  yellowish 
red  in  place  of  scarlet  or  brown-red.      Another  common  eastern  Lithosiid 


41  o  The  Moths  and  Butterflies 

is  the  pale  footman,  Crambidia  pallida,  expanding  nearly  i  inch  and 
drab  all  over;  C.  cephalica,  found  in  Colorado  and  Arizona,  expanding 
not  quite  an  inch,  has  both  wings  and  the  whole  body  of  a  delicate  shining 
silvery  white.  The  banded  footman,  Cisthene  (Ozonadia)  unijascia,  found 
all  along  the  Atlantic  and  Gulf  coasts,  expands  f  inch  and  has  the  fore 
wings  dark  with  a  narrow  curving  yellow  band  and  the  hind  wings  with 
the  base  and  disk  pink  or  yellowish,  the  apex  being  dark.  Lithosia  (Lexis) 
hicolor,  found  in  the  northern  states  and  Canada,  expands  nearly  ij  inches 
and  is  slate-colored,  with  yellow  on  the  front  margin  of  the  fore  wings,  the 
tip  of  the  abdomen,  the  prothorax,  and  the  palpi.  The  several  Rocky 
Mountain  and  desert  species  mostly  have  brick-red  or  drab  or  slaty  ground 
color,  some  unmarked  and  some  with  dark  border  on  the  hind  wings  if 
red  is  the  ground  color,  and  smoky-whitish  hind  wings  if  body  and  fore 
wings  are  drab  or  slaty. 

Another  family  of  moths  expanding  about  an  inch,  and  with  a  charac- 
teristic habitus  due  to  the  long  narrow  fore  wings,  the  small  size  of  the 
hind  wings,  and  the  contrasting  colors  of  the  wing-pattern,  are  the  Zygasnidas, 
or  SyntomidiE,  as  the  newer  nomenclature  names  them.  In  the  hind  wing, 
veins  subcosta  and  radius  are  fused,  usually  for  the  whole  length.  About 
twenty  species  of  the  family  are  found  in  this  country,  and  because,  as 
with  the  Lithosiidce,  the  larvs  are  not  of  much  economic  importance  the 
life-history  of  but  few  of  the  species  is  known.  The  majority  of  the  species, 
besides,  live  in  the  western  and  southwestern  states,  and  like  other 
mountain,  plain,  and  desert  insects  are  hardly  known  except  in  their  flying 
stage.     The  larvae  of  some  species  feed  on  grasses,  of  others  on  lichens. 

One  of  the  most  striking  species  is  Cosmosoma  auge,  found  in  the 
extreme  south,  which  has  both  fore  and  hind  wings  clear  of  scales  over 
the  base  and  disk  only,  a  border  all  around  the  veins,  and  a  small  black 
patch  at  the  tip  of  the  discal  cell  of  the  fore  wing  covered  with  black  scales. 
The  plump  body  is  scarlet,  with  the  end  of  the  abdomen  and  a  dorsal 
longitudinal  band  on  it  metallic  blue-black.  The  wings  expand  i  inch. 
Lycomoipha  is  a  genus  of  small  Zyga^nids  characterized  by  having  the 
wings  colored  in  two  strongly  contrasting  shades,  black  and  brick-red  or 
black  and  reddish  yellow.  In  L.  pholus  the  basal  two-fifths  of  each 
wing  is  yellow  and  all  the  rest  black;  in  L.  miniata  the  basal  two- 
thirds  is  red,  the  rest  black;  in  L.  grotei  all  of  the  fore  wing  is  red 
except  a  narrow  black  border  on  the  outer  margin,  while  the  anterior 
half  of  the  hind  wings  is  red,  the  posterior  half  black.  Ctenucha  is  a 
genus  of  larger  species  which  have  smoky-brown  wings  unmarked,  as 
in  C.  virginica,  a  northeastern  species,  which  has  a  yellow  head 
and  metallic  bluish-black  body,  C.  miiUijaria  and  C.  ricberoscapus, 
Pacific  coast  species  which  have   a  coral-red  head   and    shoulder-lappets 


The  Moths  and  Butterflies 


411 


and   metallic   deep-bluish   body,   or   which   have    the    fore    wings    marked 

by  a  few  conspicuous  longitudinal 

yellowish  lines  as  in  C.  venosa,  found 

in    Colorado,    New     Mexico,    and 

Texas.     Scepsis  julvicoUis,  found  in 

the  eastern  and  Mississippi   Valley 

states,    has    subtranslucent    smoky 

wings  with  a  region  clear  of  scales 

in  the  middle  of  the  hind  wings;  its 

prothoracic  collar   is  yellow  and  its 

abdomen  metallic  blue-black. 

The  "woolly-bear"  caterpillars 
(Fig.  592)  and  the  tiger-moths,  which 
are  the  same  insects  in  dilJerent 
growth  stages,  are  among  the  most 
familiar  of  caterpillar  and  moth 
acquaintances.  They  belong  to  the 
family  Arctiidae,  represented  in  this 
country  by  a  hundred  and  twenty 
species  of  which  surprisingly  many 
are  pretty  well  known  to  any  ardent  collector.  The  strikingly  colored, 
spotted,  and  banded  wings  of  the  stout  and  hairy-bodied  moths  and  the 
dense  clothing  of  long  strongly  colored  hairs  characteristic  of  most  of  the 


C      a 

Fig.  591. — Venation  of  a  Zygsenid,  Ctenncha 
virginica.  cs,  costal  vein;  sc,  subcostal 
vein;  r,  radial  vein;  ni,  medial  vein;  c, 
cubital  vein;  a,  anal  veins.  (After  Com- 
stock;    enlarged.) 


Fig.  592. — Woolly -bear  caterpillars,  Halesidota  sp.,  all  three   of  the  same  species  but 
showing  variations  in  extent  of  the  black  markings. 


larvae    are    the    recognition-marks    of   the  family.      The    moths,  too,    are 
mostly  fairly  large  and   are   readily  attracted   by   lights,  while  the  cater- 


412  The  Moths  and  Butterflies 

pillars,  trusting  to  the  uncomfortable  mouthful  of  hairs  they  offer  their 
bird  enemies,  travel  conspicuously  about  in  the  open  with  a  characteristic 
nervously  hurrying  gait.  Thus  the  Arctians  become  familiar  to  collector 
and  observer. 

The  woolliest  woolly  bear  is  the  larva,  sometimes  called  "hedgehog,"  of  the 
Isabella  tiger-moth,  Pyrrharctia  (Isia)  Isabella  (PI.  VII,  Fig.  3),  common  all 
over  the  United  States;  it  is  covered  with  a  stiff  furry  evenly  shorn  coat  black  at 
either  end  and  red-brown  in  the  middle,  and  is  comnionly  seen  in  the  autumn 
traveling  rapidly  about  in  open  places.  It  hibernates  in  larval  stage  under 
loose  bark  or  logs  or  sidewalks,  and,  after  a  brief  activity  in  the  spring,  pupates 
within  a  slight  cocoon  made  up  of  silk  and  its  own  brown  and  black  hairs. 
The  moth  which  issues  soon  is  dull  orange  with  the  front  wings  variegated 
with  dusky  and  spotted  with  black;  the  hind  wings  are  lighter  and  also 
black-spotted;  it  expands  2  inches.  The  caterpillars  feed  on  various  plants, 
sometimes  becoming  destructive,  when  in  sufficient  numbers,  to  black- 
berry and  raspberry  bushes  and  to  nursery  stock.  Lugger  says  that  they 
are  especially  susceptible  to  attack  by  muscardine,  a  parasitic  fungus  disease 
much  feared  by  silkworm-growers.  "Hedgehogs"  killed  by  muscardine  are 
found  stiffly  attached  to  their  food-plants  with  a  whitish  powder  over  the 
body  at  the  base  of  the  dense  hair  covering. 

The  yellow  bears,  common  caterpillars  on  the  leaves  of  vegetables, 
flowering  plants,  and  fruits,  distinguished  by  their  dense  but  uneven  coat 
of  long  creamy-yellow,  light  or  even  dark  brown  hairs,  are  the  larvae  of  the 
beautiful  snowy-white  miller-moth,  Spilosoma  virginica.  The  wings  bear  a 
few  (two  to  four)  small  black  dots,  and  the  abdomen  is  orange-colored 
with  three  rows  of  black  spots.  The  larv«  pupate  in  the  fall  in  cocoons 
composed  almost  wholly  of  their  own  long  barbed  hairs,  and  the  moths  issue 
in  the  spring.  There  is  usually  a  second  brood  each  year.  This  moth  is 
kept  in  check  by  many  parasites,  few  other  insects  having  to  contend  with 
so  many  of  these  insidious  enemies  of  their  own  animal  class. 

The  most  destructive  member  of  the  family  is  the  fall  web-worm,  Hyphan- 
tria  cunea,  which  makes  the  large  unsightly  silken  "nests"  in  plum-trees,  both 
wild  and  cultivated,  so  familiar  in  late  summer  and  autumn.  The  eggs 
are  deposited  in  regular  clusters  of  400  or  more  on  the  plum-leaves,  and  the 
hatching  pale-yellow  larvae  spin  small  silky  web-nests  close  together  which 
finally  get  included  in  one  large  one.  The  full-grown  larvae  are  pale  yellow- 
ish or  greenish  with  a  broad  dusky  stripe  along  each  side;  they  are  covered 
with  whitish  hairs  which  rise  from  black  and  orange-yellow  warts.  They 
often  hang  from  the  nest  or  branches  by  a  long  silken  thread.  They  pupate 
in  crevices  of  the  bark  and  other  sheltered  places  on  the  ground,  passing 
the  winter  in  this  stage.  The  milk-white  moths,  sometimes  with  small 
black  spots  on  the  wings,  sometimes  unspotted,  issue  in  late  spring  or  early 


The  Moths  and  Butterflies 


413 


summer.  They  expand  ij  inches.  There  is  much  variation  in  color  and 
pattern  in  both  moths  and  caterpillars,  many  varieties  being  found  in  a 
single  tree. 

Among  the  most  strikingly  colored  and  patterned  Arctians  are  the  numerous 
species  of  Apanresis  (Arctia).  A.  virgo  (PI.  VI,  Fig.  3),  a  common  species 
in  the  Atlantic  states,  whose  larva  feeds  on  pigweed  and  other  uncultivated 
plants,  expands  2^  inches,  has  black  fore  wings  with  the  veins  broadly  marked 
with  pinkish  yellow,  and  red  hind  wings  with  large  angularly  irregular  black 
blotches.  The  thorax  is  colored  like  the  fore  wings,  the  abdomen  like  the 
hind  wings.  Sharply  angled  black  spots  on  a  ground  of  reddish,  pinkish, 
salmon,  and  yellowish  characterize  almost  all  the  many  species  in  this  genus. 


1 

^^^ 

^■l 

k^  ^^Mi^^i^^M^ 

1 

i 

1 

w^ 

1 

k 

y 

■ 

^ 

H^^S^ 

m 

1 

. 

-^M 

■ 

i4j  I    (L* 

WM 

k:\ 

«^iiimmggg^___^ 

" 

\ 

Fig.  593. — Caterpillar  of  Halesidota  tesselata.     (After  Lugger;    natural  sj:c.) 


Striking  moths  are  Arachnis  pida  (PI.  VIII,  Fig.  4),  with  whitish  fore  wings 
marked  with  wavy  "band-like  blotches  of  pearl-gray,  and  red  hind  wings  with 
three  uneven  gray  bands;  Ecpantheria  deflorata,  the  leopard-moth  of  the  south 
Atlantic  states,  and  E.  muzina,  of  the  southwestern  states,  both  creamy  white 
with  circular  or  elliptical  black  spots  or  rings  thickly  scattered  over  the  fore 
wings,  but  only  in  a  single  submarginal  series  on  the  hind  wings;  and  Utethe- 
isa  bella  (PI.  VII,  Fig.  7),  a  familiar  little  moth  of  the  Atlantic  states  with 


4H 


The  Moths  and  Butterflies 


its  pinkish-red  hind  wings  with  black  branching  border  and  yellowish-red 
fore  wings  crossed  by  six  bending  white  bands  containing  small  black  spots. 
Attractive  and  familiar  moths  are  the  various  species  of  Halesidota,  whose 
larvae  feed  on  the  leaves  of  hickory,  oak,  and  several  kinds  of  orchard  trees. 
These  caterpillars  (Fig.  593)  are  covered  with  short  spreading  tufts  of  hairs 
white  and  black  or  yellow,  and  bear,  too,  a  single  pair  of  long  hair  pencils 
usually  black  or  orange.  They  are  often  called  tussock-caterpillars  and 
are   not    unlike    the    true    tussock-moth   larvae    (see   p.    404).     The   moths 

(Fig.  504)  have  long  narrow  fore 
wings,  and  hind  wings  only  about 
half  as  fong;  in  H.  tesseUata  the 
hind  wings  are  almost  transparent 
yellowish  (while  the  fore  wings  have 
faint  darker  short  transverse  lines 
or  blotches) ;  H.  maculata  (Fig.  595) 
has    yellowish    fore    wings    thickly 


Fig.  594.  Fig.  595. 

Fig.  594. — Halesidota  carya,  above,  and  H.  tesselala,  below.     (After  Lugger;  natural  size.) 
Fig.  595. — Halesidota  maculata.     (After  Lugger;    natural  size.) 


sprinkled  with  brown  and  blotched  with  creamy-white  spots,  the  pale  hind 
wings  being  unmarked;  H.  lobeniJa  has  the  wings  nearly  transparent,  the  fore 
wings  dusted  with  dark  scales,  and  a  regular  check  pattern  on  the  front  and 
hind  margins,  the  hind  wings  unmarked,  and  the  abdomen  of  a  beautiful 
rose  color;  H.  argentata  has  the  fore  wings  blackish  brown  with  distinct 
white  spots  all  over  the  surface,  white  hind  wings  bearing  a  single  irregular 
brown  spot  near  the  apex.  The  Callimorphas  (Fig.  596)  are  pretty,  slender- 
bodied  Arctians  with  snow-white,  creamy,  or  soft  warm  yellow-brown  wings, 
banded  with  dark  brown  or  blackish;  they  belong  to  the  genus  Hap'oa, 
whose  larvae  are  blackish  studded  with  blue  spots,  and  covered  with  short 
stiff  hairs.  All  the  species  of  Haploa  are  found  in  the  Atlantic  states.  H. 
clymene  (PI.  VII,  F'g.  5)  has  the  wings  brownish  yellow,  paler  on  the  fore  wings, 
which  are  incompletely  bordered  with  blackish  brown,  a  curious  blunt  arm 
of  this  color  projecting  in  from  the  hinder  margin;  the  hind  wings  have  a 
subcircular  dark  spot;   H.  lecontei  has  white   hind  wings,  and  brown  fore 


PLATE   Vn. 

MOTHS. 

i  =  Anisota  rubicunda 
2=Geometra  iridaria, 
3=Pyrrharctia  Isabella. 
4=Tropoea  luna. 
5  =  Haploa  clymene. 
6=Melittia  ceto 
7=Utetheisa  bella. 


PLATE  VII 


if 


'.S 


y^ 


¥ 


Mary  Wellinaii,  del. 


The  Moths  and  Butterflies  415 

wings  with  six  large  white  blotches;  H.  julvicosta  has  all  the  wings  pure 
white  with  the  front  margin  of  the  fore  wings  weakly  fulvous.  A  familiar 
Arctian  is  the  salt-marsh-caterpillar  moth  Eustigme  acrcea,  expanse  i^ 
inches,  with  creamy-white  fore  wings  and  soft  yellow-brown  hind  wings,  all 
the  wings  sparsely  dotted  with  black. 

A  small  family  which  includes  a  few  widely  distributed  and  well-known 
moths  is  the  Lasiocampida;,  of  which  the  tent-caterpillar  moths  are  the  most 
familiar.  All  the  Lasiocampid  moths,  which  are  robust,  hairy,  and  fairly 
large,  lack  the  frenulum,  having,  however,  the  humeral  angle  of  the  hind 
wing  expanded  so  as  to  overlap  the  inner  hind  angle  of  the  fore  wing.  In 
this  humeral  angle  are  one  or  two  short  supporting  veins  or  vein-spurs. 


Fig.  596. — Haploa  fitlvicosta    (above)   and  H.   contigua    (in    the   middle    and    below). 
(After  Lugger;    natural  size.) 

The  best-known  eastern  species  is  the  apple-tree  tent-caterpillar,  the 
forest  tent-caterpillar  being  also  familiar;  on  the  Pacific  coast  also  occur 
two  common  species,  one  specially  affecting  orchard  trees.  These  four 
species  belong  to  the  genus  Clisiocampa  (Figs.  598,  599);  the  moths  expand 
about  1^  inches  and  are  all  brown,  varying  in  shade  from  yellowish  to  walnut 
to  chocolate-brown,  with  a  pair  of  pale  or  distinct  light  or  darker  oblique  lines 
on  the  fore  wings.  C.  americana,  the  apple-tree  tent-caterpillar,  lays  its 
three  hundred  eggs  in  the  summer  in  a  band  or  ring  glued  around  a  small 


4.i6 


The  Moths  and  Butterflies 


twig  of  an  apple  or  wild-cherry  tree;  the  eggs  do  not  hatch  until  the  follow- 
ing spring,  when  the  young  larvae  feed  on  the  buds  and  young  leaves  of  the 
tree.     The  social  larvte  build  a  little  web  or  nest  in  the  fork  of  a  branch, 

going  out  of  it  only  to  feed.  As  the 
caterpillars  grow  they  enlarge  the  web 
until  it  becomes  a  bulky  ugly  affair 
perhaps  two  feet  long,  partly  filled  with 
excrement  and  cast  skins.  The  full- 
grown  caterpillars  are  blackish  with 
yellow  and  bluish  spots,  white  striped 
along  the  back,  and  covered  with  fine 
yellowish  hairs.  "They  feed  on  the 
young  and  tender  leaves,  and  eating 
on  an  average  two  leaves  a  day  the 
young  of  one  pair  of  moths  consume 
from  ten  to  twelve  hundred  leaves,  and 
Fig.  597.— Venation  of  Halesidota  tessel-   as  it  is  not  uncommon  to  find   from  six 

lata,     cs,   costal  vein;    sc,    subcostal   to  eight  nests  on  a   single  tree  not  less 

vein;  r,  radial  vein;   «^  medial  vein;   ^^^   seventy-five   thousand   leaves  are 

c,  cubital  vein;    a,  anal  veins.     (Alter  ■' 

Comstock;   enlarged.)  devoured,  a  loss  which  no  tree  can  long 

endure."  In  about  forty  days  the  larvae 
are  ready  to  pupate,  when  they  scatter  from  the  nest,  find  sheltered  places 
under  eaves,  fence-rails,  etc.,  and  spin  spindle-shaped  cocoons  of  white, 
almost  transparent  silk,  within  which  they  change.  After  twenty  to  twenty- 
five  days  of  pupal  life  the  winged  moths  issue  and  soon  after  lay  their 
eggs  for  next  year's  brood.  The  life-history  of  the  various  other  species 
is  similar  to  this  although  other  trees  are  chosen  for  feeding-grounds. 

The  lappet-moths,  so-called  from  the  curious  lobes  or  lappets  arranged 
along  the  sides  of  their  caterpillars,  are  of  several  species.  Tolype  velleda, 
expanding  17  to  if  inches,  has  a  white  body  with  a  black  spot  and  dusky- 
gray  wings  crossed  by  white  lines;  its  caterpillar  feeds  on  the  fohage  of 
apple-,  cherry-,  and  plum-trees,  and  is  hair-fringed  and  protectively  colored  so 
that  it  looks  much  like  an  excrescence  of  the  bark  on  which  it  habitually 
lies  when  not  feeding.  Gastropacha  americana  (Fig.  601),  the  American 
lappet-moth,  expanding  i|  inches,  is  so  hke  a  dead  leaf  in  appearance  that 
it  can  hardly  be  distinguished  when  at  rest;  it  varies  somewhat  in  color, 
but  most  individuals  are  reddish  brown  with  a  broad  interrupted  whitish 
band  across  both  wings;  the  hinder  and  outer  edges  of  the  fore  wings  and 
the  outer  edges  of  the  hind  wings  are  deeply  notched.  The  caterpillar  feeds 
on  apple,  cherry,  and  oak,  hiding  during  the  day  but  becoming  active  at 
night.  It  is  broad,  convex  above  and  flat  beneath,  ash-gray  with  fringes 
of  blackish  or  gray  hairs,  and  when  at  rest  it  is  almost  impossible  to  recognize. 


The  Moths  and  Butterflies 


417 


It  grows  to  be  2  inches  long  and  spins  a  peculiar  gray  cocoon  which  looks 
very  much  like  a  slight  swelling  of  the  twig  to  which  it  is  fastened.  The 
pupa  hibernates,  the  moth  issuing  in  June  of  the  next  year. 


Fig.  598.  Fig.  599. 

Fig.  598. — A  family  of  young  forest  tent-caterpillars,  Clisiocampa  disstria,  resting  during 
the  day  on  the  bark.     (Photograph  from  life  by  Slingerland;  one-third  natural  size.) 

Fig.  599. — The  forest  tent-caterpillar  moth,  Clisiocampa  disstria,  in  its  various  stages. 
m,  male  moth;  /,  female  moth;  />,  pupa;  e,  eggs  in  a  ring  about  twig;  g,  eggs  after 
hatching;  c,  larva  or  caterpillar.  (After  Slingerland;  moths  and  caterpillar  natural 
size,  eggs  and  pupa  slightly  enlarged.) 


Including  the  largest,  the  most  beautiful — in  popular  eyes  at  least — 
and  the  favorite  moths  for  rearing  in  "crawleries,"  the  superfamily  Saturniina 
includes  as  well  one  of  the  only  two  insects  that  have  been  domesticated 
by  man  and  reared  for  the  sake  of  their  useful  products.  The  honey-bee 
and  the  silkworm  moth  are  fairly  to  be  called  domesticated  animals.  To 
the  Saturniina  belong  the  great  cecropias,  the  marvelous  lunas,  the  regal 
and  imperial  walnut-moths,  and  the  soft-tinted  rosy  dryocampas.  Although 
the  whole  group,  divided  commonly  into  four  families,  includes  but  forty- 
two   North  American  species,  almost  every  one  of  these  is  more  or  less 


4i8 


The  Moths  and  Butterflies 


familiarly  known  to  the  amateur  collector  and  crawlery  owner.  And  popular 
books  like  Dickerson's  "Moths  and  Butterflies,"  Eliot  and  Soule's  "Cater- 
pillars and  Their  Moths,"  etc.,  which  tell  in 
detail  of  the  life-history  and  habits  of  various 
Lepidoptera,  mean  by  "moths,"  first  Saturnians, 
then  Sphingids,  and  finally  a  scant  sprinkling 
of  "others."  The  giant  vividly  colored  cater- 
pillars, the  great  silken  cocoons  safely  enclosing 
their  mystery  until  that  day  when  a  marvel  of 


a     a 

Fig.  600.  Fig.  601. 

Fig.  600. — Venation  of  Clisiocampa  americana.      cs,   costal  vein;    sc,   subcostal    vein; 

r,   radial   vein;    ;w,  medial  vein;    c,  cubital  vein;   a,  anal  veins.     (After  Comstock; 

enlarged.) 
Fig.  601. — The  American  lappet-moth,  Gastropacha  americana.     (After  Lugger;  natural 

size.) 

living  color  and  pattern  slowly  crawls  out  and  unfolds  and  takes  on  the 
seeming  of  the  perfect  cecropia  or  polyphemus,  it  is  little  wonder  that  the 
giant  silkworm-moths  are — always  never  overlooking  the  swift  and  masterful 
Sphingids — the  moths  of  popular  fancy. 

Just  because  these  moths  are  so  well  known  and  so  well  and  fully  written 
of  elsewhere  I  may  limit  my  account  of  them  to  a  brief  descriptive  catalogue 
of  adults  and  larvae  with  the  particular  aim  of  making  the  more  common 
species  determinable  by  amateurs.  The  particular  species  in  hand  once 
safely  identified,  details  of  life-history  and  habits  can  be  looked  for  in  the 
many  popular  or  technical  accounts  of  the  various  kinds.  In  all,  the  males 
can  be  distinguished  from  the  females  by  their  large  antennae  and  smaller 
bodies.     In  some  species  the  sexes  are  very  different  in  color  and  pattern. 

Of  the  genus  Samia,  the  real  giant  silkworms,  four  species  occur  in 
this  country.  S.  cecropia,  the  great  cecropia-moth  of  the  eastern  states, 
expands  5  to  6  inches,  has  red  thorax  with  white  collar,  red  abdomen 
banded  with  white  and  black  lines,  wings  with  grizzled  gray  ground,  and 
markings,  as  shown  in  Fig.  602,  of  reddish  white  and  blackish  with  clay- 
colored  outer  margins.  The  large  discal  spots  on  the  wings  are  whitish  in 
the  center,  surrounded  and  encroached  on  by  reddish,  and  margined  with  a 
narrow  black  line.  The  full-grown  larva  (Fig.  604)  is  nearly  4  inches 
long,  pale  limpid  green,  and  bears  on  its  back  conspicuous  tubercles,  coral- 


The  Moths  and  Butterflies 


419 


red  on  the  second  and  third  thoracic  segments,  bkie  on  the  first  thoracic  and 
last  abdominal,  and  yellow  on  the  others;  smaller  blue  lateral  tubercles  are 
present.  It  feeds  on  many  kinds  of  orchard-  and  forest-trees,  most  small  fruits, 
and  some  herbaceous  plants.  The  winter  is  passed  in  the  pupal  stage 
enclosed  in  a  great  pod-shaped  rusty-gray  or  brownish  silken  cocoon  about 
3  inches  long  and  i  inch  wide  in  the  middle,  composed  of  two  layers, 
an  outer  strong  "brown-paper"  layer  and  an  inner  loose  fibrous  one.  The 
pupaj  may  be    easily  found  on  trees  when  the  leaves  are  off  and  brought 


Fig.  602. — Cecropia-moth,  Samia  cecropia.     (Photograph  by  author;    natural  size.) 


into  the  house.  The  moths  will  issue  in  early  summer  through  an  opening 
which  is  left  by  the  larva  in  one  end  of  the  cocoon.  S.  Columbia  of  the  north- 
eastern states  and  Canada  is  smaller  than  cecropia,  the  angulated  discal 
wing-spots  have  hardly  any  reddish  border  and  the  transverse  outer  wing- 
border  of  white  has  no  red  outer  margin  as  in  cecropia,  the  abdomen  is  dark- 
red  brown  rather  than  red,  and  the  basal  half  of  the  front  wings  is  tinged 
with  reddish  brown.  5.  gloveri,  found  in  the  Rocky  Mountains  and  west 
to  Arizona,  is  like  Columbia,  but  as  large  as  cecropia.  S.  ceanothi  of  the 
Pacific  coast  has  the  ground  color  of  the  wings  strongly  reddish,  the  outer 


420 


The  Moths  and  Butterflies 


markings  weak    to  wanting,  the    white   transverse  wing-band  narrow  and 
with  no  reddish  border,  the  discal  spots  also  without  reddish  margin. 

The  polyphemus-moth,  Telea  polyphe- 
miis  (Fig.  605),  expanse  4  to  5  inches, 
common  in  the  whole  country,  is  ocherous 
brown  with  a  pinkish  margined  blackish 
outer  transverse  band  across  each  wing 
and  a  discal  spot  on  each  wing  with 
unsealed  clear  center;  this  latter  char- 
acter makes  the  species  at  once  unmistak- 
able; the  hind  wing-spots  are  in  the  center 
of  a  large  blackish  blotch  with  bluish 
scales  by  the  inner  margin  of  the  clear 
spot.  The  larva  (Fig.  606),  which  feeds 
on  various  forest-,  shade-,  and  orchard- 
trees,  reaches  a  length  of  3  inches  or 
more,  is  light  green  with  seven  oblique 
pale-yellowish  lines  on  each  side  of  the 
body,  and  bears  numerous  little  black 
wart-like  processes  provided  with  small 
stiff  bristles,  and  each  body  segment  has 
a  small  silvery  spot  on  the  middle.  The 
dense  oval,  completely  closed  cocoon  is 
made  of  silk  and  a  few  leaves  closely 
wrapped  and  tied  together.  It  usually 
falls  to  the  ground  in  autumn,  but  sometimes  remains  on  the  tree.  The 
moth  secretes  a  fluid  from  its  mouth  which  softens  and  partly  dissolves  one 
end  of  the  cocoon  for  its  emergence. 


Fig.  603. — Venation  of  a  Saturniid, 
Botnbyx  mori.  C5,  costal  vein;  sc, 
subcostal  vein;  r,  radial  vein;  m, 
medial  vein;  c,  cubital  vein;  a, 
anal  veins.  (After  Comstock;  en- 
larged.) 


Fig.  604. — Larva  of  Samia  cecropia.     (After  Dickerson;    natural  size.) 


In  Plate  VII,  Fig.  4,  is  shown   in  color  the  luna-moth,  or  pale  empress 
of  the  night,  Tropcea   luna    (Fig.  607),  a  marvel  of  delicate  green  tinting 


The  Moths  and  Butterflies 


421 


and  exquisite  symmetry  of  curving  outlines.  It  expands  4^^  inches,  and 
ranges  over  the  whole  country.  The  larva  is  rather  like  that  of  the  polyphe- 
mus-moth,  being  clear,  pale  bluish  green  with  a  pale-yellowish  stripe  on 


Fig.  605. — The    polyphemus-moth,     Telea    polyphemus,    and    cocoon. 
(After  Lugger;    reduced  about  one-fourth.) 

each  side  of  the  body;  each  segment  bears  about  six  small  purplish  or  rosy- 
tinged  pearl  tubercles;  at  the  tip  of  the  body  are  three  brown  spots  edged 
with  yellow.      It  feeds  on  hickory  and  walnut,  on  other  forest-trees,  and 


Fig.  606. — Larva  of  polyphemus-moth,   Telea    polyphemus. 
(After  Dickerson;    natural  size.) 

makes  a  rather  thin  but  compact  cocoon  of  silk  and  leaves. 

In    the   eastern   states    the   Asiatic    ailanthus-worm   moth,   Philosamia 
cynthia,  expanse  5  inches,  with  angulated  wings,  olive-brown  ground-color 


422 


The  Moths  and  Butterflies 


on  body  and  wings,  a  whitish  lunate  discal  spot  and  a  white  and  purplish 
transverse  bar  on  each  wing,  and  body  with  longitudinal  series  of  white 
tufted  spots,  has  become  common  near  several  cities. 

The  promethea-moth,  Callosamia  pronielhea,  expanse  3  to  4  inches,  light 
reddish  brown  in  female,  and  blackish  and  clay  color  in  male,  with  mark- 
ings as  shown  in  Fig.  609,  is  perhaps  the  most  abundant  of  all  these  giant 
moths.  Its  larva  when  full-grown  is  2  inches  or  more  in  length;  it  is  bluish 
green  and  the  body  bears  longitudinal  series  of  black  pohshed  tubercles, 
two  of  these  tubercles  on  each  of  the  second  and  third  thoracic  segments 


Fig.  607. 


-The  luna-moth,  or  pale  empress  of  the  night,  Tropcea  luna. 
(After  Lugger;   reduced  about  one-fourth.) 


being  larger  and  red  instead  of  black.  It  feeds  on  many  kinds  of  trees,  but 
Comstock  has  found  it  more  frequently  on  ash  and  wild  cherry  than  on 
others.  The  cocoon  is  long  and  slender  and  enclosed  in  a  dead  leaf  whose 
petiole  has  been  fastened  to  the  branch  with  silk  by  the  larva.  "At  the 
upper  end  of  the  cocoon  there  is  a  conical  valve-like  arrangement  which 
allows  the  adult  to  emerge  without  the  necessity  of  making  a  hole."  C. 
angulijera  is  a  moth  slightly  larger  than  promethea,  but  otherwise  hardly 
distinguishable  from  it  except  that  the  shape  and  markings  of  the  wings, 


The  Moths  and  Butterflies 


423 


r 


Fig.  608. — Cocoons:  i,  2,  3.  of  Tropma  hma;  4,  5,  6,  of  Callosamia  angtdifera;   7,  8,  9,  lo^ 
oi  Callosamia  promethea.     (After  Laurent;  somewhat  reduced.) 


424 


The  Moths  and  Butterflies 


which  vary  a  httle  in  male  and  female  of  promethea,  are  identical  in  this.     It 
is  found  also  only  in  the  Atlantic  states. 

The  lo  emperor-moth,  Automeris  io  (PI.  VI,  Fig.  5;  also  Fig.  610),  ex- 
panse 2^  to  3  inches,  is  the  most  familiar  and  the  only  eastern  species  of 
the  four  members  of  this  genus.  It  can  be  recognized  by  the  large  blue 
and  black  eye-spots  in  hind  wings  and  by  its  unmarked  fore  wings.  The 
female  has  rich  purplish-brown  fore  wings,  the  markedly  smaller  male  yellow 
fore  wings.  The  larva  (Fig.  611),  which  feeds  on  trees,  small  fruits,  corn, 
clover,  etc.,  when  full-grown  is  2^  inches  long,  and  is  pale  green  with  a 


Fig.  609. — The  proinetliL-a-moth,  Callusaiiiia  promethea,  male. 
(After  Jordan  and  Kellogg;    natural  size.) 


broad  brown  stripe  edged  with  white  and  reddish  lilac  on  each  side,  and 
has  the  body  covered  with  clusters  of  black-tipped  green  branching  spiny 
hairs  which  are  very  sharp  and  strongly  stinging.  The  thin,  irregular 
parchment-like  cocoon  made  of  tough  gummy  brown  silk  is  spun  under 
dead  leaves  or  other  rubbish  on  the  ground.  In  Texas  is  found  A.  zelleri, 
expanse  5  inches,  reddish  brown,  without  any  yellow  color  in  hind  wings; 
in  Arizona  yl.  pamina,  expanse  2^  to  3  inches,  with  yellow  around  the  white- 
centered  black  eye-spots  of  the  hind  wings;  and  in  New  Mexico  ^.  se/'/zyr/a, 
expanse  2^  to  3  inches,  with  brown-black  fore  wings  and  pale-brown  abdomen 
broadly  banded  with  red. 

With  a  single  species,  the  maia  moth,  in  the  eastern  states,  and  but  half 
a  dozen  in  the  Rocky  Mountains,  desert  and  Pacific  slope  states,  the  genus 
Hemileuca  presents  a  striking  difference  from  the  other  Saturnians  so  far 


The  Moths  and  Butterflies 


425 


described  in  the  thinly  scaled,  not  hairy,  condition  of  the  wings  and  the 
prevalence  of  black  and  white  in  the  pattern  instead  of  warmer  colors.  H. 
maid,  expanding  2^  inches,  is  subtransparent  black  with  a  broad  middle 
transverse  band  of  white  on  each  wing;  in  this  band  is  a  small  blackish  blotch 


Fig.  610. — The     lo   emperor-moth,    Automeris   io,    and   cocoon;    female    moth  above; 
male  below.     (After  Lugger;  natural  size.) 


isolated  in  the  hind  wings,  but  connected  with  the  black  of  the  base  in  the 
fore  wings.  This  species  occurs  in  the  eastern  states;  a  similar  species,  H. 
nevadensis,  being  found  from  the  Rocky  Mountains  to  the  Pacific;  H.  electra, 
found  in  southern  California,  has  the  hind  wings  blackish  red;  other  species, 
found  in  New  Mexico  and  Arizona,  are  mostly  black  and  white  with  a  red- 


426 


The  Moths  and  Butterflies 


dish  or  pinkish  tinge  here  and  there.  The  larva  of  H.  maia  feeds  on  oak; 
it  is  brownish  black  with  a  lateral  yellow  stripe,  and  has  large  branching 
spines  over  the  body  which  sting  severely. 

In   Plate  VI,  Fig.  4,  is  shown   in  proper   color  and   pattern  a  bizarre 
moth,  Pseudohazis  eglanterina,  not  uncommon  in  the  Rocky  Mountains,  which 


Fig.  611. — Larva  of  lo  emperor-moth,  Automeris  io.     (After  Dickerson;    natural   size.) 

we  may  call  the  clown.  An  allied  species,  P.  sJiastaensis,  similarly  marked 
and  colored,  is  found  on  the  Pacific  slope,  and  a  third  species,  P.  hera,  with 
pale  yellowish-white  ground-color  in  the  wings  instead  of  purplish  red,  occurs 
in  the  region  between  the  Rocky  Mountains  and  the  Sierra  Nevada. 

Two  great  moths,  the  imperial  (PI.  VI,  Fig.  2)  and  the  regal  walnut- 
moth  (Fig.  612),  are  the  most  impressive  of  a  subgroup  of  the  Saturniina 
called  the  Ceratocampidae.  They  are  all  short-bodied  and  hairy  and  show 
for  colors  exclusively  rich  warm  browns  and  soft  yellows,  light  purple  and 
rose.  A  curious  structural  characteristic  of  the  family  is  the  limiting  of  the 
pectinations  on  the  antennae  of  the  male  to  the  basal  half  of  the  antenna. 
The  regal  walnut-moth,  atheroma  regalis  (Fig.  612),  expands  fully  5  inches, 
has  a  rich  brown  ground-color  on  body  and  hind  wings,  with  the  fore  wings 
slaty  gray  with  yellow  blotches,  and  veins  broadly  marked  out  in  red-brown. 
The  larva  (Fig.  613),  4  to  5I  inches  long,  and  yellowish  brown,  reddish 
brown,  or  greenish,  is  distinguished  from  all  other  caterpillars  by  the  great, 
threatening,  but  harmless  blue-black  horns  of  the  body;  it  feeds  on  butter- 
nut, walnut,  ash,  pines,  and  other  trees.  Basilona  imperialis,  the  imperial 
moth,  is  as  large  as  the  regal  walnut,  but  with  ground-color  of  rich  yellow, 
overspread  on  base  and  outer  part  of  fore  wings  and  as  a  spot  and  band 
on  hind  wings  with  soft  brownish  purple.  The  larvae  when  full-grown  are 
3  inches  long,  brown  or  greenish,  thinly  clothed  with  long  whitish  hairs, 
and  bear  conspicuous  spiny  horns  on  the  second  and  third  thoracic  segments. 
They  feed  on  hickory,  oak,  elm,  maple,  and  other  deciduous  forest-trees, 
as  well  as  on  spruce,  pine,  juniper,  and  hemlock.     The  larvae  of  both  these 


The  Moths  and  Butterflies 


427 


great  moths  burrow  into  the  ground  to  pupate,  the  rough  brown  naked 
chrysalids  wintering  over. 


Fig.  612. — The  regal  walnut-moth,  Citheronia  regalis.   (Photpgraph  by  author;  natural  size.) 

Anisota  is  a  genus  of  smaller  moths  containing  five  species  limited  to 
the  eastern  states,  four  of  which  are  brown  and  one,  A.  riibiciinda,  rosy  and 


Fig.  613. — Larva  of  regal  walnut-moth,  Citheronia  rcgaus. 
(Photograph  by  author;    natural  size.) 

yellow.     This  latter,  called  the  rosy  dryocampa,  is  shown  in  color  in  Plate 
VII,  Fig.   I.     Its   larva,    so:r:^t!n^es    ca.led   the   green-striped   maple-worm, 


421 


The  Moths  and  Butterflies 


is  pale  yellowish  green  and  is  striped  with  many  fine  longitudinal  lines 
alternating  lighter  and  darker  than  the  ground-color.  There  are  two  horns 
on  the  second  thoracic  segment,  and  dorsal  spines  on  the  eighth  and  ninth 
abdominal  segments. 

A.  virginiensis  is  purpHsh  red  or  brown,  and  the  wings  are  nearly  trans- 


FiG.  614.  Fig.  615. 

Fig.  614. — The  orange-striped  oak-worm  moth,  Anisota  senatoria,  male.     (After  Lugger; 

natural  size.) 
Fig.  615. — The    orange-striped   oak-worm    moth,    Anisota    senatoria,    female.      (After 

Lugger;    natural  size.) 

parent  in  the  center;    the  larva,  found  on  oak,  is  grayish  or  greenish  with 
brownish-yellow  or  rosy  stripes  and  with  small  white  warty  processes  all  over 


Fig.  616. — Mulberry  silkworms,  larvae  of  Bombyx  mori.     (From  life;    natural  size.) 


the  skin;    A.  stigma,  expanse  2  inches,  is  light  ocherous  brown  with  many 
blackish  dots;    its  bright  tawny  or  orange  caterpillar  has  long  spines  on 


The  Moths  and  Butterflies 


429 


the  back;  A.  senatoria  (Figs.  614  and  615)  is  like /I.  virginiensis,  but  lacks 
the  transparent  place  in  the  middle  of  the  wing;  the  caterpillar  is  black  with 
four  stripes.  All  these  Anisota  larvai  feed  on  oaks,  and  that  of  A .  senatoria 
also  on  blackberries  and  raspberries.  Sphingicampa  (Adelocephala)  hicolor 
is  a  beautiful  moth  with  brown  fore  wings  and  dark-pink  hind  wings  with 
dusky  dots,  which  is  not  uncommon  in  the  Mississippi  Valley  and  southern 
states;  its  larvae  feed  on  the  locusts  and  the  Kentucky  coffee-bean.  In  the 
southwest  are  two  or  three  species  of  the  genus  Syssphinx  resembling  Sphingi- 
campa bicolor,  but  one,  S.  heiligbrodti,  in  Arizona,  has  iron-gray  fore  wings. 
Now  unknown  in  wild  condition,  the  long-cultivated  Chinese  or  mulberry 
silkworm,  Bombyx  mori,  is  spread  over  most  of  the  world,  living  exclusively, 
however,  under  the  personal  care  of  man.  Indeed  it  is  often  said  that  the 
worm  is  so  degenerate,  so  susceptible  to  unfavorable  circumstances,  that 
it  could  not  live  out  of  doors  uncared  for.  As  a  matter  of  fact,  however,  I 
have  bred  moths  from  silkworms  placed 
exposed  on  mulberry-trees  in  California 
immediately  after  the  first  moult.  And 
these  individuals  experienced  consider- 
able hardship  in  the  way  of  low  temper- 
atures and  dashing  rains.  The  heavy 
creamy-white  moths,  with  wing  expanse 
of  if  inches,  take  no  food  at  all,  and 
most  of  them  cannot  even  fly  despite 
their  possession  of  well-developed  wings, 
so  degenerate  are  the  flight-muscles  from 
generations  of  disuse.  The  eggs,  about  300,  are  laid  by  the  female  on  any 
bit  of  cloth  or  paper  provided  her  by  the  silkworm-growers.  They  are  yellow 
at  first,  but  soon  change  to  a  slaty  color  due  to  the  beginning  development 
of  the  embryo.  In  the  annual  race  of  silkworms,  i.e.,  the  variety  which 
produces  but  one  generation  a  year  as  compared  with  those  others  which 
produce  two  (bivoltins),  three  (trivoltins),  and  even  five  or  six  (multivoltins), 
the  development  of  the  eggs  soon  ceases,  and  they  go  over  the  winter,  hatching 
in  the  following  spring  at  the  time  the  mulberry-trees  begin  leafing  out. 
The  larvae  (Figs.  616  and  617)  must  be  well  fed  with  fresh  mulberry  or  osage- 
orange  leaves  (they  may  at  a  pinch  be  carried  through  on  lettuce)  from  which 
all  rain-  or  dew-drops  should  be  wiped  off.  The  worms  moult  every  nine 
or  ten  days,  ceasing  to  feed  for  a  day  before  each  moulting,  during  the  forty- 
five  days  of  larval  life,  spinning  before  the  last  moult  (pupation)  the  dense 
white  or  golden  silken  cocoon  which  is,  to  man,  the  silkworm's  raison  d'etre. 
In  this  spinning  the  thread  is  at  first  attached  irregularly  to  near-by  objects, 
but  after  a  sort  of  loose  net  or  web  has  been  made  the  spinning  becomes 
more  regular,  and  by  the  end  of  three  days  a  thick  firm  symmetrical  closed 


Fig.  617. — Mulberry  silkworm,  show- 
ing front  view  of  head  and  thorax. 
(From  life;    natural  size.) 


43° 


The  Moths  and  Butterflies 


cocoon,  composed  of  a  single  continuous  silken  thread  averaging  over  looo  feet 
long,  is  completed.  Inside  this  cocoon  the  larva  pupates,  and  if  undisturbed 
the  chrysalid  gives  up  its  damp  and  crumpled  moth  after  from  twelve  to  fourteen 


v^'^"!!^ 


days  or  longer.  A  fluid  secreted  by  the  moth  softens  one  end  of  the  cocoon 
so  that  the  dehcate  creature  can  force  its  vi^ay  out.  But  this  is  not  the  usual 
fate  of   a  silkvirorm  pupa.      The  professional. grower  must  save  the  cocoon 


The  Moths  and  Butterflies 


431 


from  injury  by  the  moth,  so  he  kills  his  thousands  of  pupae  by  dropping 
the  cocoons  into  boiling  water  or  by  putting  them  into  a  hot  oven.  Then, 
after  cleaning  away  the  loose  fluffy  silk  of  the  outside,  he  finds  the  beginning 
of  the  long  thread  which  makes  the  cocoon,  and  with  a  clever  little  reeling- 
machine  he  unwinds,  unbroken,  its  hundreds  of  feet  of  merchantable  silk  floss. 
From  here  to  the  silk-dress  stage  is  a  story  not  entomological,  but  one  of 
elaborate  machines  and  processes  of  human  devising. 

Hovering,  humming-bird-like,  in  the  early  dusk  over  the  deep  flower- 
cup  of  a  petunia  or  honeysuckle  or  great  jimson-weed,  with  its  long  flexible 
proboscis  thrust  deep  down  to  the  nectaries,  and  the  swift  wings  making  a 


Fig.  619. — Larva  of  the  achemon  sphinx-moth,  Philampelus  achemon. 
(After  Lugger;  natural  size.) 


faint  haze  on  either  side  of  the  trim  body,  the  sphinx-moth,  or  hawk-moth, 
or  humming-bird  moth,  as  variously  called,  is  a  familiar  garden  acquaintance. 
But  that  he  is  but  one  of  a  hundred  different  American  species;  that  he  has 
cousins  red  and  cousins  green,  somber  cousins  and  harlequin  cousins;  that, 
strong-winged,  clean-bodied,  exquisitely  painted,  and  honey-fine  in  his  taste 
as  he  is  now,  his  earliest  youth  was  passed  as  a  "disgusting,"  soft,  fat,  green 
tomato-worm  or  tobacco-worm  or  grape-vine  dresser,  and  that  at  a  later 
adolescent  period  he  lay  buried  in  the  ground,  cased,  mummy-like,  in  a  dark- 
brown  sarcophagus — all  this  may  not  be  as  familiar.  Still,  excepting  the 
giant  silkworm-moths,  the  Saturnians,  no  other  moth  group  is  so  much 
affected  by  collectors  and  crawlery  proprietors  as  the  Sphingida?.  Thus 
the  various  adolescent  stages  of  several  hawk-moth  species  are  known  to 


432 


The  Moths  and  Butterflies 


many  amateurs,  and  numerous  different  sphingid  species  will  be  found  in 
any  collection  of  Lepidoptera.  The  uniformity  of  structural  character  in 
larvae  and  adults  of  the  various  species,  and  the  general  similarity  of  habits 
and  life-history,  make  the  family  a  coherent  one,  and  one  readily  distinguish- 
able from  other  moths.     These  moths,  with  few  exceptions,  have  long,  nar- 


FiG.  620. — Larva    of    the    sphinx-moth,    Phlegethontitis    Carolina.     (After    Jordan    and 
Kellogg;    one-half  natural  size.) 

row,  pointed  fore  wings,  very  small  hind  wings,  a  smooth-coated,  compact, 
cleanly  tapering  body,  and  a  long  proboscis,  coiled  when  not  in  use,  like 
a  watch-spring,  on  the  front  of  the  head  (Fig.  509).  The  colors  and  pat- 
terns are  extremely  varied,  but  uniformly  quietly  beautiful  and  harmonious. 


Fig.  621. — Larva  of  Phlegethontius  celeiis.     (After  Soule;    somevsrhat  reduced.) 

The  larvae  (Fig.  619)  are  naked,  usually  green,  often  with  repeated  oblique 
whitish  lines  on  the  sides,  and  bear  a  conspicuous  sharp-pointed  horn, 
or,  in  fewer  instances,  a  fiattish,  button-like  shining  tubercle,  on  the  back 
of  the  eighth  abdominal  segment.     The  caterpillars,  or  "worms,"  feed  on 


The  Moths  and  Butterflies 


433 


the  foliage  of  various  plants,  and  when  full-grown  most  of  them  descend 
and  burrow  into  the  ground  to  pupate.  The  chrysalid  is  naked,  with  firm, 
dark^brown  wall,  and  is  distinguished  by  the  odd  jug-handle-Hke  sheath 
for  the  developing  long  imaginal  proboscis.     A  few  larvae  pupate  on  the 


Fig.  622. — Pholus  achenion,  above,  and  Pholus  pandorus,  below. 
(After  Lugger;  natural  size.) 

ground  in  a  slight  cocoon  made  of  silk  and  a  few  leaves  tied  together.  The 
insects  hibernate  in  the  pupal  stage;  a  few  are  said  to  be  double-brooded. 
The  name  sphinx,  applied  to  these  moths  by  Linnaeus  a  century  and  a  half 
ago,  is  suggested  by  the  curious  attitude  assumed  by  the  larvae  when  dis- 
turbed; the  front  part  of  the  body  is  lifted  (Fig.  620)  clear  of  the  object 
on  which  the  insect  is  resting,  and  the  head  is  bent  forward  on  the  thoracic 
feet.     This  position  may  be  held  rigidly  for  hours. 

Of  the  many  species  found  in  this  country  we  can  refer  to  but  a  few  of 
the  more  familiar  or  beautiful  or  interesting  ones,  and  these  references  may 
be  made  brief  because  of  the  colored  figures  which  are  grouped  in  our  frontis- 
piece.    These  figures  render  descriptions  unnecessary. 


434 


The  Moths  and  Butterflies 


Best  known  of  all  the  hawk-moths,  both  in  larval  and  adult  stage,  are 
the  five-spotted  sphinges,  the  tomato-  and  tobacco-worm  moths,  Phlege- 
ihontius  quinquemaculata  (celeus)  and  P.  sexta  {Carolina)  (PI.  VIII,  Fig.  3). 


Fig.  623. — Larva  of  Pholus  achemon.     (After  Soule;    natural  size.) 

Quinquemaculata  is  the  commoner  in  the  north,  sexta  in  the  south;  in  both 
the  larva  (Figs.  620  and  621)  is  green  with  oblique  white  stripes  on  the  side 
and  a  long  sharp  caudal  horn,  and  feeds  on  tomato-,  tobacco-,  and  potato- 
leaves  or  jimson-weed.  The  horn  of  sexta  is  red, 
that  of  quinquemaculata  green  or  blue-black. 
The  pupae  are  long  and  slender  and  dark 
brown  (green  at  first),  and  are  often  found  when 
plowing  or  digging  up  fields  in  which  these  plants 
have  been  grown.  The  moth  of  P.  quinquemaculata 
has  ashy-gray  wings,  with  zigzag  markings,  while 
the  wings  of  sexta  are  not  thus  marked.  The 
great  pandorus  sphinx,  Pholus  (Philampelus) 
pandonis  (PI.  I,  Fig.  i),  found  in  the  eastern 
and  central  states,  is  one  of  the  most  beautiful 
of  all  moths.  The  larvas  feed  on  grape-vines 
and  Virginia  creeper,  and,  measuring  four  inches 
long  when  full-grown,  are  rich  reddish  brown 
with  five  conspicuous  cream-colored  spots  along 
Fig.  624.  —  Grape  -  vine  each  side;  a  shining  black  eye-like  tubercle  takes 
spliinx  -  moth,  Ampelo-  ^j^g  j^^^  ^f  ^  caudal  horn.  It  pupates  under- 
phaga    myron.      (Natural  ^  /tt-       <      \         vu  1  • 

size.)  ground.      P.  achemon  (rig.  022),  with   markings 

much  like  pandorus,  but  with  strong  rosy  color- 
ation instead  of  greenish,  has  a  larva  which  also  feeds  on  grape  and  Vir- 
gina  creeper  and  may  be  recognized  by  its  six  (instead  of  five)  lateral 
cream-colored  blotches. 


JTIV   .-1 


PLATE  VIII. 

MOTHS. 

i  =  Deilephila  lineata. 
2=Chser()campa  tersa. 
3  =  Phlegethontius  sexta. 
4=Arachnis  picta. 
5  =  Alypia  octomaculata. 
6=Anato]mis  grotci. 
7  =  Plusia  simplex. 


PLATE   VIII 


niarv  Welhnan^  del. 


The  Moths  and  Butterflies 


435 


The  beautiful  little  Ampdophaga  myron,  with  soft  red-brown  hind  wings 
and  brownish-gray  fore  wings,  patterned  as  shown  in  Fig.  624,  has  a  pea- 
green,  cream-banded,  and  yellow  and  lilac  spotted  larva  known  as  the  hog- 
caterpillar  of  the  vine,  so  named  from  its  form — the  third  and  fourth  seg- 
ments being  greatly  swollen,  the  head  and  first  two  segments  small— and 
its  destructiveness  to  grape-vines.  When  ready  to  pupate  it  spins  a  brown 
silken  open-meshed  cocoon  on  the  ground  under  leaves  or  other  rubbish. 


Fig.  625. — The  double-eyed  sphinx,  Smerinthus  geminatiis,  above;    Paonias  excacatus, 
in  middle;    and  P.  myops,  below.     (After  Lugger;    natural  size.) 


A.  versicolor  (PI.  I,  Fig.  3)  is  a  beautiful  cousin  of  myro7i  with  greenish 
overlaid  on  the  brown.  An  extremely  slim,  slender-bodied,  and  slender- 
winged  sphinx  is  Chcerocampa  (Theretra)  tersa  (PI.  VIII,  Fig.  2),  found  in  the 
northern  states.  It  is  very  swift.  An  abundant  and  familiar  hawk-moth  found 
all  over  the  United  States  is  the  white-lined  sphinx,  Deilephilalineata  (PL  VIII, 
Fig.  i).  Its  caterpillar  feeds  on  various  plants,  as  grape,  apple,  watermelon, 
buckwheat,  turnip,  and  purslane;  the  latter  seems  to  be  the  preferred  plant. 


43^ 


The  Moths  and  Butterfiies 


Exceedingly  variable  in  color  and  pattern,  it  is  usually  yellow-green  with  a 
conspicuous  longitudinal  row  of  elliptical  spots  on  each  side  of  the  back, 


Fig.  626. — Larva  of  Smerinthus  geminatus.     (After  Lugger;    natural  size.) 

each  spot  consisting  of  two  curved  black  lines  enclosing  a  bright  crimson 
blotch  and  a  pale-yellow  line;   all  the  spots  are  connected  by  a  pale-yellow 


P'iG.  ()27. — Sphinx  gordius.     (After  Lugger;    natural  ^izc.) 

line  edged  above   with    black.      Sometimes    the  larvae    are    black,  with   a 
narrow  yellow  line  along  the  back  and  a  series  of  paler-  and  darker-yellow 


The  Moths  and  Butterflies 


437 


spots.  The  double-eyed  sphinx,  Smerinthus  geminatiis  (PI.  I,  Fig.  2;  also 
Fig.  625),  is  a  common  species  whose  larvae  feed  on  apple,  plum,  ash,  willow, 
birch,  and  other  trees;  the  full-grown  caterpillar  (Fig.  626)  is  2\  inches 
long,  apple-green,  with  seven  oblique  yellow  stripes  on  each  side  of  the 
body  and  a  violet  caudal  horn.  The  genus  Sphinx  (Fig.  627)  contains 
nearly  twenty  species,  all  of  them  soberly  patterned  with  grayish,  brownish, 
and  blackish,  and  most  of  them  expanding  more  than  three  inches. 


Fig.  628. — Larva  of  the  abbott-sphinx,   Thyreus  abbotti.      {Alitr  Soule;    natural  size.) 

While  most  hawk-moths  have  narrow  tapering  fore  wings  and  a  slender 
tapering  smooth-coated  body,  structural  conditions  indicating  a  well-de- 
veloped flight  power,  a  familiar  species,  the  modest  sphinx,  Marumba  modesta 
(PI.    I,  Fig.  4),  found    all    over    the  country,  is    hairy,  heavy-bodied,  and 


Fig.  629. — Larva  of  abbott-sphinx,   Thyreus  abbotti;    note  difference  in  pattern  from 
larva  shown  in  Fig.  628.     (After  Soule;    natural  size.) 

broad-winged.  The  full-grown  larvae  are  3  inches  and  more  long,  whitish, 
yellowish,  and  bluish  green,  with  fine  white  dots  all  over  the  skin;  the  cau- 
dal horn  is  short.  They  feed  on  "balm-of-Gilead,"  poplar,  and  other  trees. 
Another  species  of  unusual  shape  is  the  beautiful  dark-brown  and  canary- 
yellow  small  tufted-bodied  abbott-sphinx,  Thyreus  (Sphecodina)  abbotti 
(PI.  I,  Fig.  6),  found  in  the  Atlantic  and  Mississippi  Valley  states.  Its 
larvae  (Figs.  628  and  629)  feed  on  woodbine  and  grape.  They  are  ''ashes- 
•of-rose"  color,  finely  transversely  lined  with  dark  brown  and  with  longitu- 
dinal series  of  brown  blotches.  They  have  a  large  circular,  eye-like  tubercle 
in  place  of  a  caudal  horn.     They  may  appear  in  two  different  patterns  as 


438 


The  Moths  and  Butterflies 


shown  in  Figs.  628  and  629.  The  pupa  is  found  under  dead  leaves  or  other 
rubbish.  Very  similar  in  appearance  and  habits  is  the  grape-vine  amphion, 
Amphion  nessiis  (Fig.  630),  of  the  same  size  and  shape  and  colors  and  found 


Fig.  630.  Fig.  631. 

Fig.  630. — The   grape-vine   amphion,   Amphion  nessus.     (After  Beutenmiiller;  natural 

size,  i|-2  inches  expanse  of  wings.) 
Fig.  631. — Larva  of  clear-winged  sphinx,  Hemaris  difflnis.     (After  Soule;  natural  size.) 

in  the  same  states;  it  may  be  distinguished,  however,  by  a  pair  of  conspicu- 
ous narrow,  bright-yellow  bands  across  the  abdomen.  The  larvae  are  pale 
yellowish  green  or  chocolate-brown  with  various  obscure  darkish  stripes. 


Fig.  632. — The  death's-head  sphinx-moth;  note  skull-like  markings  on  thorax  between 
wings.  This  moth  is  looked  on  with  superstitious  dread  by  many  people.  (Photo- 
graph by  author;    natural  size.) 

A  few  sphinx-moths  have  the  wings  partly  clear.     These  are  called  the 
clear-winged  sphinxes  and  belong  to  the  genus  Hemaris.     H.  thysbc  (PI.  I, 


The  Moths  and  Butterflies 


439 


Fig.  5)  is  the  most  abundant  Eastern  species,  although  H.  diffinis,  with 
bright-yellow  hairs  in  place  of  brownish  yellow  on  thorax  and  abdomen,  is 
common.  In  Colorado  and  Utah  is  found  a  smaller  species,  H.  brucei, 
with  yellowish  thorax  and  abdominal  band,  and  in  California  are  one  or  two 
varieties  of  H.  diffinis.  The  larva  of  H.  diffinis  (Fig.  631)  feeds  on  honey- 
suckle and  snowberry-bush  and  is  pale  green  above,  darker  green  on  the 
sides,  with  three  brown  stripes  on  the  under  side;  the  caudal  horn  is  yellow 
with  blue-black  tip;  some  of  the  caterpillars,  as  is  common  among  the  larvae 
of  this  family,  are  brown  instead  of  green.  It  is  two-brooded.  Moths  just 
issued  from  the  chrysalid  have  scales  over  all  of  the  wing  surface,  but  these 
scales  are  so  loosely  attached  on  the  discal  area  that  the  first  few  flights 
dislodge  them,  so  that  the  "clear- wing"  comes  about.  The  larvae  of 
H.  thy  she  feed  on  viburnum,  snowberry,  and  hawthorn. 

BUTTERFLIES. 

Taken  all  in  all  the  butterflies  are  the  most  familiar  and  attractive  insects 
to  people  in  general;    their  size,  beautiful  color-patterns,  and  daytime  flight 


Fig.  633. — The  Parnassian  butterfly,  Parnassius  smintheus,  which  lives  in  the  Rocky 
Mountains  and  Sierra  Nevada  at  an  altitude  of  5000  feet  and  more.     (Natural  size.) 

chiefly  account  for  this.  Six  hundred  and  fifty  butterfly  species  (compare 
with  the  six  thousand  species  of  moths)  are  accredited  to  this  country  in 
the  latest  authoritative  catalogue  of  North  American  Lepidoptera.  These 
represent,  according  to  this  catalogue,  thirteen  families;  a  more  usual  classi- 
fication, however,  groups  all  these  species  into  six  families.  As  this  latter 
arrangement  is  in  use  in  most  of  the  insect  manuals,  it  will  be  adopted  in  this. 
Comstock,  who  has  given  the  classification  of  the  Lepidoptera  much  attention, 
gives  the  following  key  to  families: 


440 


The  Moths  and  Butterflies 


Fig.  638.  Fig.  637. 

Fig.  634. — Venation  of  a  Hesperid,  Epargyreus  tityrus.     (After  Comstock;    enlarged.) 
Fig.  635. — Venation  of  a  Papilionid,  Papilio  polyxenes.     (After  Comstock.) 
Fig.  636. — \ena.\.\onoi  s.'HymphsiMd,  Basilarchia  astyanax.    (After  Comstock;  enlarged.) 
Fig.  637. — Venation  of  a  Lycaenid,  Chrysophaniis  thoe.     (After  Comstock;    enlarged.) 
Fig.  63S. — ^Venation  of  a  Pierid,  Pontia  protodice.     (After  Comstock;    enlarged.) 
For  all:  cs,  costal  vein;  sc,  subcostal  vein;  r,  radial  vein;  m,  medial  vein;  c,  cubital 
vein;    a,  anal  veins. 


The  Moths  and  Butterflies  441 


KEY   TO    FAMILIES    OF   BUTTERFLIES    (LEPIDOPTERA   WITH   THE 
ANTENNA   FILIFORM,   WITH   A   CLUB,    OR   KNOB,   AT   THE   TIP). 

A.      With  the  radius  of  the  fore  wings  five-branched  and  with  all  of  these  branches 
arising  from  the  discal  cell  (Fig.  634);    club  of  antennae  usually  terminated  by  a 

recurved    hook (Skippers.)      Supcrfamily    Hesperiina. 

B.      Head  of  moderate  size;   club  of  antennas  large,  neither  drawn  out  at  the  tip 
nor  recurved.     Large  skippers  with  wing  expanse  of  2  inches  or  more. 

Megathymid^  (p.  441). 

BB.  Head  very  large;   club  of  antennce  usually  drawn  out  at  the  tip  and  with  a 

distinct  recurved  apical  crook.     If  the  crook  is  wanting,  the  species  expand 

less    than    1}    inches Hesperiid/E    (p.  442). 

AA.  With  some  of  the  branches  of  radius  of  the  fore  wings  coalesced  beyond  the  apex 
of  the  discal  cell  (Fig.  635);    club  of  antennae  not  terminated  by  a  recurved  hook. 

(The  butterflies.)     Superfamily  Papilionina. 
B.      Cubital  vein  of  the  fore  wings   apparently  four-branched  (Fig.  635);  most  of 
the  species  with  tails  on  the  hind  wings. 

(The  swallow-tails  and  parnassians.)     Papilionid.e   (p.  446). 
BB.  Cubital  vein  of  fore  wings  apparently  three-branched  (Fig.  636). 

C.      With   only  four  well-developed  legs,   the  fore  legs  being  unused,   much 

shorter  than  the  others,  and  folded  on  the  breast  like  a  tippet,  except 

in  the  female  of  Hypatus;    radius  of  fore  wings  five-branched  (Fig.  636), 

(The  brush-footed  butterflies.)     Nymphalid^  (p.  450). 

CC.  With  six  well-developed  legs;    radius  of  fore  wings,  with  rare  exceptions, 

only  three-  or  four-branched   (Fig.   637). 

D.  Medial  vein  of  the  fore  wings  arising  at  or  near  the  apex  of  the 
discal  cell  (Fig.  637),  except  in  Feniseca  tarquinius, in  which  the 
wings  are  dark  brown  with  a  large  fulvous  spot  on  each. 

(The  blues  and  coppers.)     Lyc^nid^  (p.  443). 
DD.  Medial    vein    of   the  for^,  wings  united  with  last  branch  of   radius 
for  a  considerable  distance  beyond  the  apex  of  the  discal  cell  (Fig. 
638);  ground  color  white,  yellow,  or  orange. 

(The  whites  and  sulphurs.)  Pierid^  (p.  444). 

The  family  Megathymidse,  or  giant-skippers,  contains  but  one  genus, 
Megathyma,  represented  by  but  five  species,  of  which  none  is  found  outside 
of  the  southern  and  southwestern  states.  The  best-known  and  most  widely 
distributed  species  is  the  yucca-borer,  M.  yucccr,  whose  larvae  live  as  bur- 
rowers  in  the  roots  of  several  species  of  yucca,  and  are  from  4  to  6  inches 
long.  The  eggs  are  laid  on  the  leaves  and  the  young  larva?  spend  a  short 
time  above  ground  in  a  cylinder  made  of  a  rolled  leaf  tied  across  with  silk. 
Later  they  tunnel  into  the  stem  and  downwards  into  the  root,  sometimes  to 
a  distance  of  2  feet  or  more.  When  ready  to  pupate  they  crawl  up  to 
the  chimney-like  funnel  at  the  top  of  the  burrow  and  transform  there.  The 
moth  expands  2^  inches,  is  deep  umber-brown  with  a  notched  ferruginous 
band  and  other  smaller  blotches  on  the  fore  wings,  and  the  hind  wings  with 
a   ferruginous   border.     The   other  giant-skippers  are   of  similar   size   and 


442  The  Moths  and  Butterflies 

markings,  and  all  of  them  are  more  moth-like  than  butterfly-like  in  general 
appearance.  They  may  be  looked  on,  indeed,  as  a  sort  of  connecting  link 
between  the  moths  and  the  true  butterflies. 

The  Hesperidae,  or  skipper-butterflies  (PI.  IX),  are  a  great  family  of  small^ 
big-headed,  robust-bodied  butterflies  of  obscure  patterning  in  browns  and 
blackish  (a  few  forms  white  and  dark  gray).  Nearly  two  hundred  species 
are  known  in  this  country,  but  few  of  them  are  at  all  familiarly  recognized 
as  distinct  species;  general  collectors  and  amateurs  know  them  better 
grouped  into  generic  units,  as  Erynnis,  Amblyscirtes,  Eudamus,  Thorybes, 
Pholisora,  etc.  Indeed,  but  few  professional  entomologists  feel  competent 
to  undertake  the  identification  of  Hesperid  species.  A  few  weU-marked  or 
specially  numerous  and  wide-spread  forms  are,  however,  fairly  well  known. 
The  caterpillars  of  all  have  large  heads,  constricted  necks,  and  bodies  thick 
in  the  middle  and  tapering  both  ways,  and  often  make  protecting  nests  of 
leaves  and  silk.  The  silver-spotted  skipper,  Epargyretis  titynis  (PI.  V, 
Fig.  3),  is  abundant  over  all  the  country  and  is  readily  recognizable  by 
its  large  size  and  distinctive  pattern;  the  broad,  irregular,  silver  spot  is  on 
the  under  side  of  the  hind  wing.  The  caterpillar  feeds  on  various  Legu- 
minosae,  especially  wistaria  and  locust,  and  when  full-grown  is  i|  inches 
long,  with  large,  ferruginous  head  bearing  two  large  orange  spots,  and  lemon- 
green  body  transversely  banded  with  darker  green;  it  builds  a  nest  or  case 
of  leaves,  in  which  it  remains  when  not  feeding;  it  pupates  either  in  this 
larval  nest  or  makes  a  loose  cocoon  somewhere  on  the  ground,  hibernating 
in  this  stage.  Another  of  the  larger  species  is  the  cuiious  long- tailed  skipper, 
Eudamus  proteus,  found  in  the  south  Atlantic  states  (ranging  as  far  north 
as  New  York  City)  and  distinguished  by  the  tailed  hind  wings  and  iridescent 
green-brown  color.  The  genus  Hesperia  includes  a  dozen  or  more  specieS' 
which  are  thickly  white-spotted  on  a  blackish-brown  ground,  giving  them 
a  checkered  gray  appearance;  most  of  these  checkered  skippers  are  limited 
to  the  western  states,  but  one,  H.  tessellaia,  is  found  commonly  all  over 
the  country.  It  expands  i^  inches,  and  has  even  more  white  than  dark  on 
the  wings;  it  flies  rapidly  about  close  to  the  ground  and  lays  its  eggs  on 
various  mallows;  the  larva  is  green  with  a  dark  interrupted  dorsal  line,  dark 
lateral  bands,  and  a  pale  band  below  the  spiracles. 

A  whole  host  of  skippers  are  the  "  sooty -wings,"  members  of  several 
genera,  but  almost  impossible  to  be  distinguished  by  means  of  written 
descriptions.  They  vary  in  size  from  an  expanse  of  i  inch  to  nearly  2  inches, 
and  have  the  wings  grayish  brown  to  blackish  brown  to  truly  sooty,  usually 
with  obscure  indications  of  markings  on  both  wings  and  almost  always 
with  a  few  small  distinct  white  spots  near  the  apex  of  the  fore  wings.  The 
small  sooty-wing,  Pholisora  catidlus,  common  in  the  east,  expands  i  inch 
and  has  uniformly  nearly  black  wings  with  a  few  distinct  white  dots  on 


PLATE    IX. 


SKIPPER  BUTTERFLIES.      (After  Skinner.) 
Fig.    I 


II 

12 

13 

14 

IS 

16 

17 
18 
19 

20 

21 
22 

23 
24 

25 
26 

27 
28 


Painphila  lioboniok,  male,  upper  side. 
"  "     under  side. 

"  "         female,  under  side. 

"      upper  side. 
' '        zabulon,  male,  upper  side. 
"  "  "     under  side. 

"  "       female,  under  side. 

"  "  "      upper  side. 

"        scudderi,  male,  upper  side  (type). 
"  "        female,  upper  side  (type). 

"        bcUus,  male,  up{)er  side. 
"     underside. 
"        panoquin,  male,  upper  side. 
"     underside. 
"        stigma,  male,  upper  side  (co-type). 

underside. 
' '        pittacus,  male,  upper  side. 
"  "     under  side. 

' '        rhesus,  male,  upper  side. 
"  "  "     underside. 

' '        nemorum,  male,  upper  side. 
"        massasoit  var.  suffusa,  male,  under  side. 
' '        draco,  female,  under  side. 
' '        loammi,  male,  under  side. 
"        alcina,  male,  upper  side  (type). 
' '         panoquinoides,  male,  upper  side  (type) 
TEgiale  .streckeri,  male,  upper  side. 
Archonias  lyceas,  upper  side. 


PLATE    IX 


The  Moths  and  Butterflies 


443 


the  fore  wings.  Several  large  species,  known  as  dusty-wings,  expanding 
i^  to  if  inches,  with  grayish-brown  to  blackish-brown  wings,  belonging  to 
the  genus  Thanaos,  are  common.  Another  large  group  of  nearly  indis- 
tinguishable species  is  that  of  the  Pamphilas  (PI.  IX).  These  skippers  are 
mostly  tawny  and  are  specially  recognizable  by  a  discal  black  patch  in  male 
specimens,  which  appears  like  an  oblique  scorched  streak  near  the  center 
of  each  fore  wing.  This  patch  contains  certain  peculiar  scales  which  give 
off  scent  presumably  attractive  to  the  females.  Erynnis  sassacus  (PI.  X, 
Fig.  5),  common  in  the  Atlantic  states,  is  a  good  example  of  the  group. 
The  least  skipper,  Ancyloxypha  numitor  (PI.  V,  Fig.  5),  is  the  smallest 
commonly  seen  and  differs  from  other  skippers  in  lacking  the  recurved 
hook  at  the  tip  of  the  antennae  and  in  having  a  slender  body.  The 
pale-yellow  pilose  larva  feeds  on  grasses,  especially  those  that  grow  in  wet 
places. 

The  small  butterflies  popularly  known  as  blues,  coppers,  and  hair- 
streaks  compose  the  family  of  Lyca?nidai,  or  gossamer-winged  butterflies,  of 
which  a  hundred  and  twenty-five  species  are  recorded  from  the  United  States, 
mostly  the  western  half.  The  popular  names  express  well  the  colors  and 
pattern  characteristic  of  the  group.  They  are  delicate,  light-winged,  slender- 
bodied  butterflies  rarely  expanding  more  than  an  inch  and  a  half  and  either 
bluish  (pale  whitish  blue  to  brilliant  metaUic  dark  blue)  or  coppery  or  reddish 
or  dark  brown,  often  with  small  blackish  spots,  or  marked  with  short  fine 
little  lines,  hair-streaks,  on  the  under  side  of  the  wings,  and  often  with  dehcate 
little  tail-like  processes  projecting  from  the  hinder  margin  of  the  hind  wings. 
The  larvae  are  flattened,  short,  broad,  small,  forked,  slug-like  caterpillars 
with  small  retractile  heads;  those  of  a  few  species  distinguish  themselves 
from  all  other  butterfly  larvae  by  feeding  on  other  insects,  especially  aphids. 
The  chrysalid  is  naked,  suspended  from  the  posterior  tip  and  supported  by 
a  silken  line,  or  "bridle,"  about  its  middle. 

Often  to  be  seen  fluttering  or  clustered  about  wet  spots  in  the  roadway 
are  numbers  of  delicate  little  pale-blue  butterflies  with  under  side  of  w^gs 
almost  white  and  conspicuously  dotted  with  small  black  spots  and  with 
white-ringed  slender  antennae;  these  are  "blues,"  some  species  of  the  old 
genus  Lycaena  now  broken  up  by  modern  systematists  into  a  half  dozen  or 
more  different  genera.  The  spring  azure,  Cyaniris  pseudargiolus  (PL  V, 
Fig.  4),  is  a  wide-spread  and  common  example  of  the  group;  with  its  several 
varieties  it  ranges  over  the  whole  continent,  and  it  is  one  of  the  few  "blues" 
whose  young  stages  are  known.  The  larvas,  which  curiously  secrete  honey- 
dew  from  little  openings  on  the  seventh  and  eighth  abdominal  segments,  feed 
on  the  "buds  and  flowers  of  various  plants,  especially  those  of  dogwood 
(Comics),  Cimifuga,  and  Actinomeris."  As  many  as  three  broods  appear 
in  a  year.     The  various  species  of  blues  differ  slightly  in  size,  in  shade  of 


444  The  Moths  and  Butterflies 

coloring,  as  grayish  blue,  lilac-blue,  purple-blue,  etc.,  in  number  and  distinct- 
ness of  the  small  black  spots,  but  only  an  expert  can  determine  the 
species. 

Less  in  number  of  species  and  perhaps  not  quite  so  familiar  are  the 
"coppers"  with  orange,  red-brown  or  dark-brown  wings  conspicuously 
spotted  with  black.  Fig.  4  of  PI.  X  shows  the  color,  markings,  and  size 
of  a  typical  "copper,"  Heodes  hypophlaas,  "one  of  the  commonest  butter- 
flies in  the  United  States."  Most  of  the  other  coppers  have,  however,  hardly 
as  bright-red  a  ground  color  on  the  fore  wings,  some  being  really  somber. 
Most  of  them,  too,  are  a  little  larger  than  hypophlceas.  A  species  patterned 
and  colored  much  like  hypophlceas,  but  a  half  larger,  is  Chrysophanns  thoe, 
found  in  the  Atlantic  states  and  west  to  the  Rocky  Mountains.  The  har- 
vester, Feniseca  tarquinius,  small,  with  bright  orange-yellow  above  spotted 
with  black  and  mottled  gray  and  brown  underneath,  is  a  common  species 
all  through  the  eastern  states  west  to  the  Mississippi  River;  its  larva  feeds 
on  the  woolly  plant-lice  like  the  alder  blight,  apple-tree  aphid,  etc. 

The  hair-streaks,  mostly  belonging  to  the  genus  Thecla,  have  short  narrow 
lines  or  streaks  on  the  under  sides  of  the  wings,  and  are  usually  provided 
with  one  or  more  delicate  little  "tails"  on  the  hind  wings.  They  vary  in 
color  from  a  dull  brown  to  a  splendid  glancing  blue  or  blue-green.  They 
usually  have  one  or  more  reddish  spots  at  the  base  of  the  "tails"  and  the 
under  sides  of  the  hind  wings  are  often  greenish  or  parti-colored.  Thecla 
halesus,  the  "great  purple  hair-streak"  (PI.  V,  Fig.  9),  is  our  largest 
species,  and  is  found  in  the  southern  half  of  the  country.  Like  the  blues 
the  hair-streaks  are  very  difiicult  to  classify  to  species;  indeed  professional 
entomologists  are  not  at  all  satisfied  with  our  present  systematic  knowledge 
of  the  Lycaenids. 

In  the  extreme  southwest  are  found  rather  rarely  the  few  species  of 
"metal-marks,"  Lemonias  and  Calephelis,  black  and  reddish  checkered 
Lycaenids,  which  occur  in  this  country.  Sometimes,  as  in  L.  virgiilti,  the 
wings  are  spotted  with  white.  The  vernacular  name  is  derived  from  a  few 
small  lead-colored  or  pearly-white  spots  near  the  outer  margin  of  the  wings. 
The  tiny  metal-mark,  Calephilis  ccBnius,  expanding  only  |  inch,  and  with 
the  reddish-brown  wings  spotted  with  small  steely-blue  markings,  comes 
as  far  north  as  Virginia. 

A  smaller  family  than  the  Hesperida?  or  Lyca?nida?,  but  with  numerous 
better-known  members,  is  the  Pieridae,  the  whites,  yellows,  and  orange- 
tips.  Because  the  larvae  of  several  species  feed  on  cabbage  and  other 
cruciferous  plants,  the  unhappy  name  of  cabbage-butterflies  is  sometimes 
applied  to  them.  The  common  whites  and  yellows  are  the  most  famihar 
of  roadside  butterflies,  but  of  the  sixty  species  composing  the  family  in  this 
country,  only  half  a  dozen  occur  in  the  northeastern  states,  the   south   and 


The  Moths  and  Butterflies  445 

west  being  the  favored  regions  of  distribution.  All  the  species  except  two  or 
three  are  of  medium  size,  that  is,  have  an  expanse  of  ij  to  2  inches,  and 
have  white  or  yellow,  from  light  sulphur  to  orange,  as  ground  color,  with 
markings  of  black.  The  larva)  are  mostly  green,  longitudinally  striped, 
with  more  or  less  distinct  lines  usually  paler,  and  harmonize  so  thoroughly 
in  coloration  and  appearance  with  the  green  foliage  on  which  they  feed  that , 
they  are  not  often  seen.  The  chrysalids  are  naked,  supported  at  the  pos- 
terior tip  and  also  by  a  loose  silken  bridle,  and  distinguished  from  other 
butterfly  pupai  by  a  conspicuous  median-pointed  process  on  the  head  end. 
The  males  of  many  Pierids  give  off  a  pleasing  aromatic  odor  which  comes 
from  certain  scent-scales  (androconia)  scattered  about  over  the  wing-surface. 
If  the  fore  wings  of  a  freshly  caught  male  cabbage-butterfly  be  rubbed 
between  thumb  and  finger,  this  scent  can  be  readily  smelled  on  the  fingers. 
It  is  used  to  attract  or  excite  the  females. 

The  three  most  abundant  whites  in  the  eastern  and  northern  states  are 
Pontia  protodice,  P.  napi,  and  P.  rapcz,  the  larvae  of  all  three  species  being 
voracious  cabbage-eaters.  P.  rapce,  the  European  cabbage-butterfly,  is  a 
European  butterfly  which  got  to  Quebec  about  i860  and  since  then  has 
spread  over  the  whole  country  and  is  the  most  serious  pest  among  all  the 
butterflies;  it  expands  from  if  inches  (male)  to  nearly  2  inches  (female), 
has  faintly  yellowish-white  wings  with  the  base  and  apex  of  fore  wings 
blackish  and  with  two  circular  black  dots  on  fore  wings  of  the  female  and 
one  in  the  male;  there  is  a  single  black  spot  (in  male  very  faint)  on  front 
margin  of  hind  wings;  under  sides  of  hind  wings  and  tip  of  fore  wings  lemon- 
yellow.  P.  protodice,  the  southern  cabbage-butterfly,  or  checkered-white, 
has  at  least  three  black  spots  besides  a  blackish  apical  border  on  the  fore- 
wings  of  the  male,  while  both  the  wings  of  the  female  are  much  checkered 
with  blackish  brown ;  the  under  side  of  the  hind  wings  is  white  in  the  male. 
P.  napi,  the  northern  cabbage-butterfly,  or  mustard-white,  appears  in  eleven 
or  twelve  appreciably  different  patterns,  but  characterized  through  all  this 
variety  by  the  pale  or  distinct  grayish  bordering  of  the  veins;  there  is  but 
little  blackish  on  the  wings  of  the  male,  at  most  one  or  two  circular  spots 
and  a  blackish  apical  border.  In  the  western  states  the  species  of  Pontia 
which  will  be  found  by  most  collectors  are  beckeri,  distinguished  by  green 
markings  on  the  under  side  of  the  hind  wings;  occidentalis,  much  like  pro- 
todice, and  sisymbri,  a  small  species  with  the  veins  of  the  hind  wings  widely 
bordered  with  blackish  brown  on  the  under  side.  A  beautiful  Pierid  is 
the  pine-white,  Neophasia  menapia,  of  the  Pacific  states  and  Colorado;  in 
both  male  and  female  the  black  color  above  is  limited  to  the  fore  wings; 
there  is  a  border  along  the  costal  margin  from  base  to  beyond  the  middle, 
where  it  bends  in  along  the  outer  margin  of  the  discal  cell  as  a  swollen  club- 
like blotch;    in  addition  the  apex  is  broadly  bordered  with  black  in  which 


446  The  Moths  and  Butterflies 

three  or  four  white  spots  appear;  in  some  specimens  the  hind  wings  have 
a  narrow  broken  border  of  scarlet  on  the  under  side. 

Of  the  yellows,  or  sulphurs,  the  most  familiar  in  the  eastern  states  is 
Eurymus  philodice,  the  clouded  sulphur,  expanding  i^  to  2  inches;  the 
wings  are  pale  sulphur-yellow  with  black  outer  borders  and  with  a  discal 
black  spot  on  each  fore  wing  and  orange  spot  on  each  hind  wing;  in  the 
female  the  black  border  of  the  fore  wings  is  very  broad  and  contains  five  or 
six  irregular  yellow  spots.  Similar  in  pattern,  but  with  the  ground  color  of  the 
wings  bright  orange  instead  of  pale  yellow,  is  the  orange- sulphur,  E.  eury- 
theme,  common  through  all  the  West.  Both  of  these  species  are  polychro- 
matic and  polymorphic,  that  is,  show  marked  variation  in  ground  color  and 
in  size,  some  individuals  called  albinos  being  white,  some  called  negros 
being  suffused  with  blackish;  some  are  very  small,  others  unusually  large. 
A  variety  of  names  has  been  given  to  some  of  these  aberrations  because 
of  their  regular  appearance  under  certain  seasonal  conditions.  The  longi- 
tudinally striped  green  larvae  of  both  species  feed  on  clover.  Another  com- 
mon sulphur  in  the  southern  and  western  states  is  the  dog-face,  large  with 
pointed-tipped  front  wings  and  the  yellow  color  of  these  wings  so  outlined 
by  the  black  base  and  broad  border  as  to  produce  a  rough  likeness  to  a  dog's 
head  seen  in  profile;  a  small  discal  black  spot  serves  as  the  eye.  The  south- 
ern species  is  Zerene  cmsonia  (PI.  V,  Fig.  10),  the  Pacific  coast  species  Z.  eiiry- 
dice.  The  caterpillars,  which  are  green  with  a  whitish  longitudinal  stripe  and 
a  transverse  dark  line  on  each  segment,  feed  on  various  Leguminosae.  Another 
common  southern  and  western  species  is  Terias  nicippe,  the  black-bordered 
orange  (PL  XI,  Fig.  2),  whose  larvae  feed  on  cassia.  A  striking  species 
is  the  cloudless  sulphur,  Catopsila  euhule,  the  largest  of  the  Pierids,  expand- 
ing 2^  inches;  it  occurs  in  the  southern  and  southwestern  states,  its  larva 
feeding  on  cassia.  At  the  other  extreme  in  size  is  the  dainty  sulphur, 
Nathalis  iole,  (PI.  V,  Fig.  7),  the  smallest  member  of  the  family,  expanding 
but  I  inch ;  it  has  the  same  range  and  food  habits  as  the  cloudless  sulphur. 

In  the  western  states  occur  seven  or  eight  species  of  the  pretty  little 
Pierids  known  as  orange-tips;  only  one  species,  Synchloe  genutia  (PI.  XI, 
Fig.  3),  is  found  in  the  east.  All  are  small  and  most  of  them  are  readily 
distinguished  by  the  characteristic  orange-colored  apex  of  the  fore  wings 
as  shown  in  the  colored  figure  of  genutia.  S.  sara,  with  two  named  varie- 
ties, reakirtii  and  sara,  is  the  commonest  western  species.  The  larvae  of 
the  orange-tips,  so  far  as  known,  feed  on  Cruciferae. 

Perhaps  the  most  striking  and  admired  of  all  familiar  insects  are  the 
great  swallowtail  butterflies.  They  have  an  easy,  half-fluttering,  half-soar- 
ing flight;  their  unusual  size  and  their  black  and  yellow  (or  greenish-white) 
tiger-like  markings  make  them  so  conspicuous  that  they  are  fascinatingly 
apparent  to  the  most  casual  observers.      Twenty-one  different  swallowtail 


The  Moths  and  Butterflies 


447 


butterflies  are  found  in  the  United  States.  Combined  with  them  in  the 
family  Papilionidte  are  two  species  of  curious  thinly  scaled  black-  and  red- 
spotted  white  butterflies  called  parnassians,  which  live  exclusively  in  high 


Fig.  639. — Swallow-tailed   butterflies,  Papilio   rutulus.     (From   life;     one-half 

natural  size.) 

altitudes  in  the  Rocky  and  Sierra  Nevada  Mountains.  Two  more  species 
are  found  in  high  latitudes  on  this  continent,  namely  in  Alaska.  Parnas- 
siiis  smintheus  (PI.  V,  Fig.  8;  also  Fig.  633)  with  four  varieties  is  found 
in  both  the  Colorado  Rockies  and  Sierra  Nevada,  while  P.  clodius,  a  larger 


448 


The  Moths  and  Butterflies 


species  with  more  translucent  fore  wings,  is  found  only  on  the  Pacific  coast 
and  in  the  Wyoming  mountains.  I  have  seen  P.  smintheus  in  great  numbers 
in  the  beautiful  fiower-dotted  glacial  parks  of  Colorado  from  an  altitude 
of  6000  feet  upward.  The  wings  are  so  thinly  scaled  that  they  are  nearly 
translucent,  and  the  scales  themselves  are  narrow  and  club-like,  so  different 
indeed  from  those  of  other  butterflies  that  they  probably  have  some  special 
function  not  yet  understood.  The  larvae  are  "flattened,"  having  a  some- 
what leech-like  appearance;  they  are  black  or  dark  brown  in  color,  marked 
with  numerous  light  spots.  The  chrysalis  is  short  and  rounded  at  the  head, 
and  pupation  takes  place  on  the  surface  of  the  ground,  among  leaves  and 
rubbish,  a  few  loose  threads  of  silk  being  spun  about  the  spot  in  which  trans- 
formation occurs. 

The  swallowtails  (Fig.  639),  all  except  five  of  which  belong  to  the  genus 
Papilio  (a  name  given  them  a  century  and  a  half  ago  by  Linnaeus,  the  first  great 

classifier  of  animals  and  plants),  are  readily 
distinguished  by  the  longer  or  shorter  "tails," 
one  to  three,  which  project  backward  from 
the  hind  wings.  The  ground  color  is  black, 
sometimes  suffused  with  metallic  bluish  or 
greenish,  and  the  markings  consist  of  yellow 
or  greenish -white  bands  and  blotches  together 
with  a  few  red,  orange,  and  blue  eye-spots  on 
the  upper  and  under  sides  of  the  hind  wings. 
The  larvae  are  large,  cylindrical,  fleshy,  naked 
caterpillars  usually  conspicuously  banded  or 
spotted  with  green,  black,  yellow,  orange, 
and-  white.  They  are  provided  with  a  pair 
of  fleshy  and  flexible  colored  "horns"  (osmateria)  which  can  be  protruded 
from,  or  withdrawn  into,  the  front  thoracic  segment  and  which  give  off  a 
strong  musky  scent  sufficiently  disagreeable  to  repel  many  threatening 
enemies  of  the  caterpillar.  The  chrysalids  (Fig.  640)  are  naked,  sus- 
pended by  the  tail  from  a  silken  button  and  supported  by  a  silken  girdle 
or  "bridle."  They  often  mimic  very  closely  the  coloration  and  surface 
configuration  of  the  tree-trunk  or  other  object  to  which  they  are  attached 
(Fig.  640).  Poulton,  an  English  naturalist,  has  been  able  to  obtain  chrys- 
alids of  a  single  swallowtail  species  of  many  different  colors  by  enclosing 
the  larvae  just  before  pupation  in  separate  boxes  lined  with  paper  of  different 
colors.  The  color-tone  of  the  chrysalid  tended  strongly  toward  that  of  the 
environing  paper.  Such  a  color  plasticity  is  certainly  of  much  advantage 
to  the  insect  in  rendering  the  exposed  and  defenceless  chrysalid  indistin- 
guishable. (See  Chapter  XVII  for  a  discussion  of  "color  and  its  uses.") 
One  of  the  best-known  butterflies  of  the  east  is  the  zebra  swallowtail, 


v'4-   n^^ 

'%«..j^  '#"^ 


'"^•^fey^ 


rS\i.^ 


Fio  640. — Chrvbdhcl  of  a  swal- 
low-tailed buiierfly,  Papilio  sp 
(Natural  size.) 


PLATE   X. 

BUTTERFLIES. 

1  =  Cercyonis  alope. 

2  =  Vanessa  atalanta. 

3  =  PapiIio  cresphontes. 
4=Heodes  hypophloeas. 
5  =  Erynni3  sassacus. 
6=Basilarchia  arthemis. 
7  =  Euvanessa  antiopa. 


PLATE  X 


V  Mary  Weilntnn,  del. 


The  Moths  and  Buttertiies  449 

Iphidides  ajax  (PL  V,  Fig.  2),  which  is  distinguished  from  all  other 
swallowtails  by  its  black  and  greenish-white  wings  and  its  long  tails;  it 
appears  in  three  forms,  one,  marcellus,  emerging  in  early  spring  with  tails 
f  inch  long  and  tipped  with  white;  another,  telamonides,  appearing  in 
late  spring,  a  little  larger,  with  tails  -f  inch  long  and  bordered  with  white 
on  each  side  for  half  the  length  or  more,  and  the  third  the  typical  ajax,  still 
larger,  appearing  in  late  summer  and  autumn.  Both  of  the  first  two  forms 
may  come  from  a  single  brood,  some  of  the  hibernating  chrysalids  producing 
butterflies  earlier  than  others.  It  seems  to  depend  wholly  on  the  time  of 
issuance  and  not  at  all  on  the  character  of  the  parent  whether  an  individual 
shall  be  of  the  marcellus  or  of  the  telamonides  form.  The  ajax  individuals 
are  those  that  are  produced  from  eggs  laid  in  the  spring  by  either  marcellus 
or  telamonides  individuals.  Also  some  few  chrysalids  in  every  brood  delay 
disclosing  butterflies  until  the  next  spring.  "  Marcellus  and  telamonides  thus 
produce  ajax  the  same  season,  or  either  marcellus  or  telamonides  in  the  follow- 
ing spring;  ajax  produces  itself  the  same  season  or  one  of  the  others  in  the 
spring;  but  neither  marcellus  nor  telamonides  is  produced  the  same  season 
by  any  of  the  forms"  (Scudder).  The  larvae  of  this  species  are  pea-green, 
naked,  thickest  in  the  thorax,  with  transverse  markings  consisting  of  black 
dots  and  lines  and  slender  yellow  stripes  besides  a  yellow-edged,  broad,  vel- 
vety b^ack  stripe  on  the  thorax.     They  feed  on  papaw. 

Papilio  turnus,  the  tiger  swallowtail,  or  Turnus  butterfly  (PI.  V,  Fig.  6), 
is  another  common  species,  with  a  striking  "negro"  form  called  glaucus. 
In  glaucus  the  disk  of  the  wing  is  wholly  dusted  over  with  black  scales  so 
that  the  bands  can  be  hardly  seen.  It  is  found  only  in  regions  where  there 
are  two  or  more  broods  a  year,  and  is  represented  by  females  alone.  The 
tiger  swallowtail  ranges  clear  across  the  continent,  and  sometimes  occurs 
in  great  numbers;  Scudder  says  that  on  a  cluster  of  Hlacs  6g  specimens  were 
captured  at  one  time  by  closing  the  two  hands  over  them.  The  larvae,  which 
feed  on  many  plants  but  particularly  like  wild-cherry,  are  naked  and  leaf- 
green,  with  the  front  part  of  the  body  much  enlarged  and  bearing  a  double 
stripe  of  yellow  and  black  across  the  back,  as  well  as  a  pair  of  yellow-black 
and  turquoise  eye- spots  in  front  of  this  band  and  several  rows  of  turquoise 
dots  behind  it.  On  the  Pacific  coast  occur  P.  riitulus  (Fig.  639)  and  P. 
eurymedon  of  the  same  general  pattern  of  turnus,  the  first  being  black 
and  yellow  as  turnus  is,  but  the  second  being  black  and  pale  greenish  or 
yellowish  white.  In  the  Rocky  Mountains  is  found  the  splendid  Daunus 
swallowtail,  P.  daunus,  larger  than  Turnus  and  with  two  tails  on  the  hind 
wings  and  a  third  tail-like  lobe  at  the  inner  angle.  The  larva  of  rutulus 
feeds  on  alder  and  willow,  of  eurymedon  on  Rhamnus  and  other  plants, 
and  of  daunus  mostly  on  rosaceous  plants. 

Of  different  pattern  is  the  fine   giant  swallowtail,  P.  cresphontes  (PL  X, 


450  The  Moths  and  Butterflies 

Fig.  3),  native  in  the  south,  but  now  gradually  spreading  north.  The 
caterpillar,  sometimes  called  "orange-puppy"  in  Florida,  feeds  on  orange- 
and  lemon-trees,  besides  other  plants,  and  is  swollen  in  front  of  the  middle, 
with  the  anterior  part  of  the  body  rusty  brown  with  lateral  stripe,  the  hinder 
end  of  which,  including  two  or  three  segments  and  a  broad  saddle  in  the 
middle,  is  cream-yellow  flecked  with  brown. 

A  smaller  widely  distributed  and  well-known  PapiHo  is  the  common 
Eastern  black  swallowtail,  P.  polyxenes,  represented  by  five  named  varie- 
ties besides  the  type  form.  The  black  wings  are  crossed  by  two  rows  of 
yellow  spots,  the  inner  ones  the  larger,  and  there  is  a  series  of  yellow  mar- 
ginal lunules;  incomplete  bluish  spots  lie  between  the  two  yellow  rows  of 
spots  on  the  hind  wings,  specially  distinct  and  large  in  the  female.  The 
larva  feeds  on  parsnips,  caraway,  etc.,  and  is  green-ringed  with  black  and 
spotted  with  yellow.  P.  troiliis,  the  spice-bush  swallowtail  of  the  eastern 
and  middle  states,  has  a  single  row  of  well-separated  yellow  spots  near  the 
outer  margin  of  each  wing,  with  indications  of  a  bluish  or  greenish  row  inside 
this,  specially  distinct  on  the  hind  wings;  there  is  an  orange  spot  at  each 
end  of  this  row  on  the  hind  wings.  The  larva  lives  on  spicewood  and  sassa- 
fras and  makes  a  protecting  nest  by  tying  the  edges  of  a  leaf  together.  The 
pipe-vine  swallowtail,  Laertias  philenor,  has  no  band  of  yellow  spots,  but  only 
a  few  indicated  lilac-colored  remnants  of  spots,  and  has  the  hind  wings  suf- 
fused with  beautiful  glossy  blue-green,  especially  beyond  the  base;  its  cater- 
pillar feeds  on  Dutchmen's  pipe  and  a  wild  species  of  Aristolochia,  common 
in  the  Appalachian  forests.  There  are  two  Papilionids  without  tails,  viz., 
Ithohahis  acaiida,  found  in  New  Mexico,  and  I.  polydamas,  found  in 
Florida;  both  are  beautiful  butterflies,  much  like  P.  philenor  in  color  and 
marking. 

The  largest  family  of  Rhopalocera  is  that  of  the  Nymphalidse,  or  brush- 
footed  butterflies,  the  vernacular  name  partly  describing  their  most  dis- 
tinctive structural  peculiarity,  namely  the  marked  reduction  (atrophy)  of 
the  fore  legs  to  be  functionless  little  hairy  brush-Uke  processes  without  tar- 
sal claws  on  the  feet;  in  both  sexes  these  fore  feet  lie  folded  on  the  thorax, 
"like  a  tippet,"  as  Comstock  has  said.  This  and  the  possession  of  an  always 
five-branched  radial  vein  in  the  fore  wing  are  about  the  only  structural 
characteristics  common  to  all  the  butterflies  of  this  large  family.  The  species 
range  from  small  to  large,  present  a  bewildering  variety  of  coloring  and  pattern 
and  an  equal  variety  of  larval  habit  and  appearance.  All  the  chrysalids 
are  naked,  usually  angular,  and  are  suspended  head  downward  by  the  tail 
without  other  support.  Nearly  250  species  of  Nymphalids  are  recorded 
from  this  country,  and  the  majority  of  the  best-known  and  most  abundant 
butterflies  in  any  locality  belong  to  the  group.  Some  systematists  consider 
the   brush-footed  butterflies  to  form   several   distinct   families — this  is   the 


The  Moths  and  Butterflies 


451 


point  of  view  taken  by  the  author  of  the  latest  catalogue  of  North  American 
Lepidoptera — while  those  who  believe  in  the  family  unity  of  the  group  sub- 
divide it  into  a  number  of  subfamilies. 

In  the  face  of  the  large  number  of  beautiful,  interesting,  and  familiar 
species  of  Nymphalidae  we  can  only  select,  for  description  in  our  limited 
space,  a  few  of  the  most  familiar  and  interesting.  The  special  collector 
and  student  of  butterflies  will  find  awaiting  him  a  large  literature  mostly 
readily  available,  and  to  this  he  must  refer  for  anything  like  a  comprehensive 
account  of  the  species  of  this  family. 

The  all-conquering  American  butterfly  is  the  monarch,  Anosia  plexip- 
pus  (PI.  XI,  Fig.  4;  also  Fig.  641),  sometimes  called  the  milkweed-butter- 


FlG.  641. — The  monarch  butterfly,  Anosia  plexippus  (above),  distasteful  to  birds,  and 
the  viceroy,  Basilarchia  archippus  (below),  which  mimics  it.  (Three-fourths  natural 
size.) 

fly  because  of  the  food-plant  of  its  larva.  This  great  red-brown  butterfly 
king  ranges  over  all  of  North  and  South  America,  and  has  begun  its  invasion 
of  other  countries  by  getting  a  foothold  on  the  west  coast  of  Europe  and 
in  almost  all  of  the  Pacific  islands  and  in  Australia.  I  have  found  the  mon- 
arch the  most  abundant  butterfly  through  all  of  the  Hawaiian  Islands  2000 
miles  distant  from  the  Californian  coast,  and  still  2000  miles  farther  into  the 
great  Pacific  in  the  Samoan  Islands  it  is  also  the  dominant  butterfly  species. 
Its  success  is  due  to  its  hardiness,  its  strong  flight  power,  the  abundance  and 


452 


The  Moths  and  Butterflies 


cosmopolitan  distribution  of  its  food-plant,  and  finally  and  most  important 
its  inedibility — to  birds.  It  secretes  in  its  body  an  ill-tasting  acrid  fluid, 
and  birds  soon  learn  to  let  these  disagreeable  butterfly  morsels  alone.  For 
the  sake  of  this  immunity  another  butterfly  species,  the  viceroy,  Basilarchia 
archippus  (PL  XI,  Fig.  i;  also  Fig.  641),  which  is  not  ill-tasting,  mimics  in 
extraordinary  degree  the  color  pattern  of  the  monarch,  so  that  it  must  be 
constantly  mistaken  for  the  disagreeable  monarch  and  is  passed  unmolested 
by  experienced  birds.  The  monarch  in  the  eastern  states  has  a  migratory 
habit  not  unHke  that  of  birds,  great  swarms  flying  south  in  the  autumn  to  the 
Gulf  states  and  West  Indies,  returning  north  again  in  the  spring,  not  in  swarms, 
however,  but  singly.  It  ranges  as  far  north  as  Canada.  It  has,  too,  a  curious 
habit  of  assembling  in  great  numbers  in  a  few  trees,  like  blackbirds  or  crows 
in  a  "roost,"  and  hanging  there  quietly  in  masses  and  festoons,  many  indi- 
viduals clinging  only  to  each  other  and  not  to  the  branches  at  all.  On  cer- 
tain great  pine  trees  near  the  Bay  of  Monterey  on  the  Californian  coast  I 
have  seen  myriads  of  monarchs  thus  "sembled."  The  eggs  are  laid  singly 
on  the  leaves  of  various  milkweed  species,  Asclepias  cornuli  the  favored 
kind,  and  hatch  in  about  four  days.  The  larva  (Fig.  791)  attains  its  full 
growth  in  two  or  three  weeks  and  is  a  conspicuous  object  with  its  greenish- 
white  body  regularly  banded  with  narrow  black  and  yellow  stripes;  it  has 
two  pairs  of  slender  black  filaments,  one  on  the  second  thoracic  and  the  other 
on  the  eighth  abdominal  segment.  The  beautiful  plump  chrysalid  is  pea- 
green,  smooth,  and  rounded  with  a  few  black  and  gilt  spots  and  bands.  The 
pupal  stage  lasts  from  nine  to  fifteen  days.  There  is  but  one  generation  a 
year  in  the  north,  but  two  appear  in  the  south.  The  winter  is  passed  by 
the  adult  butterfly  in  the  warm  region  of  the  subtropics. 

Although  the  viceroy,  Basilarchia  archippus,  closely  resembles  the 
monarch  in  its  red-brown  ground  color,  black-bordered  veins,  and  small 
white  spots,  only  one  of  the  half-dozen  other  species  of  the  same  genus  is 
at  all  like  it.  This  one  is  B.  floridensis  found  in  the  southern  states.  The 
others  have  a  blackish  ground-color  with  the  hind  wings  suffused  with 
greenish  blue  and  a  few  conspicuous  reddish  blotches  on  the  under  side 
of  both  wings,  as  in  the  red-spotted  purple,  B.  astyanax,  common  in  the  East, 
or  broadly  banded  with  white,  as  in  the  banded  purple,  B.  arthemis  (PI.  X, 
Fig.  6),  of  the  northeastern  states,  or  have  a  blackish-brown  ground  with 
broad  white  band  and  red-brown  apex  of  the  fore  wings,  as  in  Lorquins 
Admiral,  B.  lorquini,  of  the  Pacific  states.  The  larvae  of  Basilarchia 
feed  on  oaks,  birches,  willows,  currants,  and  various  other  trees  and  shrubs, 
and  are  odd-appearing  caterpillars  with  numerous  prominent  tubercles  or 
bosses  on  the  back. 

Beautiful  and  abundant  Nymphalids  are  the  angle-wings,  tawny  above 
with  black  markings,  dead-leaf-like  below  and  often  with    a  little   silvery 


The  Moths  and  Butterflies 


453 


comma-spot.  The  comma-butterfly,  Polygonia  comma  (PI.  XI,  Fig.  6; 
also  Fig.  642),  is  a  familiar  eastern  representative  of  the  angle-wings.  On  the 
under  side  of  each  hind  wing  is  a  small  but  distinct  silver  comma  or  C  spot. 


Fig.  642. — The  comma-butterfly,  Polygonia  comma;   two  butterflies,  a  caterpillar,  and 
empty  chrysalid  on  gooseberry  branch.     (After  Lugger;  natural  size.) 

The  spiny  greenish-brown  larva:;  feed  on  hops,  nettles,  and  elms.     The  pale 
wood-brown  chrysalids  with  metallic  golden  or  silver  spots  are  commonly 


454 


The  Moths  and  Butterflies 


known  as  hop-merchants.  If  the  spots  are  golden,  hops  are  to  bring  high 
prices;  if  silvery,  low  prices!  The  violet-tip,  P.  interrogationis,  is  another 
common  eastern  angle-wing  and  has  on  the  under  side  of  the  hind  wings  a 
double  silver  spot  a  little  like  a  question-mark  but  more  like  a  semicolon. 


1 

.^^^j^H^i 

x7..:,  ami 

'                i-S. 

■** 

iM 

l^^ft^       ^^9 

Kt 

^oA 

V     ■^ 

r 

' 

Fig.  643. — The  larva  of  the  violet-tipped  butterfly,  Polygonia  interrogationis,  making  its 
last  moult,  i.e.,  pupating.     (Photograph  from  Hfe  by  author;   slightly  enlarged.) 


Its  chestnut-colored,  pale-spotted,  spiny  larva  feeds  on  hops,  elms,  and 
linden.  Fig.  643  shows  a  caterpillar  just  pupating,  and  Fig.  644  shows 
the  formed  chrysalid.  There  are  eight  other  species  of  Polygonia  in  the 
United  States. 

The  Vanessas  are  among  the  best  known  of  our  butterflies.  Three 
species,  V.  atalanta  (PI.  X,  Fig.  2),  the  red  admiral,  V.  huntera,  the  painted 
beauty,  and  V.  cardiii,  the  thistle-butterfly,  are  found  all  over  the  United 
States,  and  in  addition  a  fourth,  V .  carycc,  the  west-coast  lady,  occurs  on  the 
Pacific  coast.  The  latter  three  species  are  but  little  like  atalanta,  having 
the  wings  blackish  brown,  plentifully  and  irregularly  marked  with  orange 
and  whitish;  underneath  there  are  true  eye-spots;  huntera  may  be  dis- 
tinguished from  cardni  by  having  but  two  complete  eye-spots  instead  of 
several,  and  caryce  differs  from  cardui  by  the  absence  of  the  rosy  tint  peculiar 
to  that  species,  the  tawnier  ground-color  of  the  upper  surfaces,  and  the  com- 
plete black  band  which  crosses  the  discal  cell  of  the  fore  wings.     Atalanta 


PLATE   XI. 

BUTTERFLIES. 

1  =  Basilarchia  archippus. 

2  =  Terias  nicippe. 
3=Synchloe  genutia. 
4=Anosia  plexippus. 
5  =  Anasa  andria. 
6=Polygonia  comma. 


PLATE    XI 


Mary  IVeUman,  del. 


The  Moths  and  Butterflies 


455 


and  cardiii  occur  also  in  Europe,  and  cardui  is  held  to  be  the  most  nearly 
cosmopolitan  of  all  butterflies,  ranging  over  nearly  the  whole  earth  outside 
the  arctic  and  antarctic  regions.  Its  larvai  feed  on  thistles  by  preference, 
but  on  almost  any  composite  if  necessary:  those  of  huntera  on  everlasting 
and  other  Gnaphalieas;  those  of  atalanta  on  nettles;  vi^hile  those  of  caryce 
feed  on  Lavatera  assiirgenliflora.     All  these  larvae  are  spiny. 

Tvi^o  striking,  widely  distributed,  and  abundant  butterflies  are  the  mourn- 
ing-cloak, Euvanessa  aniiopa  (PI.  X,  Fig.  7),  and  the  peacock-butterfly, 
or  buckeye,  Junonia  cxnia  (PI.  V,  Fig.  i).  Both  are  found  over  nearly 
all  of  our  country,  and  the  mourning-cloak  is  common  in  Europe.     The 


Fig.  644. — Chrysalid  or  pupa  of  the   violet-tipped  butterfly,  Polygonia  intcrros^ationis. 
(Photograph  from  life  by  author;    sUghtly  enlarged.) 


larva  of  the  buckeye  is  black-gray  marked  with  minute  black-edged  orange 
dashes  and  dots  transversely  arranged,  and  has  long  spines  all  over  its  body; 
it  feeds  on  Scrophulariaceae,  especially  Gerardia.  The  larva  of  the  mourning- 
cloak  is  velvety  black  sprinkled  with  white  papilla?  and  with  a  row  of  large 
medio-dorsal  orange  spots,  and  has  spines  much  longer  than  the  body  seg- 
ments. A  curious  butterfly  of  the  Mississippi  Valley  and  Great  Plains 
is  An(^a  andria,  the  goatweed-butterfly  (PI.  XI,  Fig.  5).  The  larva, 
which  is  naked,  gray-green,  and  studded  with  numerous  paler  points,  feeds 
on  species  of  Croton,  the  goatweeds.     The  American  tortoise-shell,  Aglais 


456  The  Moths  and  Butterflies 

milberti,  which  occurs  commonly  in  the  North,  has  brownish-black  wings 
with  a  broad  orange  fulvous  band  between  the  middle  and  outer  margin; 
there  are  also  two  fulvous  spots  in  the  discal  cell  of  the  fore  wing.  The 
larva,  which  feeds  on  nettles,  is  spiny,  velvety  black  above,  greenish  yellow 
below,  and  profusely  dotted  with  whitish  spots  or  points.  Another  northern 
butterfly  is  the  Compton  tortoise,  Eiigonm  j-album,  which  resembles  in 
general  color  and  pattern  the  angle-wings  (Polygonia),  but  has  the  hinder 
margin  of  the  fore  wings  straight,  the  markings  on  these  wings  heavier, 
and  a  whitish  spot  on  both  fore  and  hind  wings  near  the  apex;  there  is  also  a 
small  L-shaped  silver  spot  on  the  under  side  of  the  hind  wings.  Eugonia 
calijornica,  the  California  sister,  is  a  beautiful  butterfly  common  on  the 
Pacific  coast  and  found  occasionally  in  the  Rocky  Mountains;  it  is  velvety 
blackish  brown  with  a  broad  white  transverse  bar  across  each  wing,  inter- 
rupted on  the  fore  wings  and  tapering  out  on  the  hind  wings,  and  with  a 
conspicuous  large  orange-brown  patch  nearly  filling  the  apex  of  the  fore 
wings.     Its  larva  feeds  on  oaks. 

Two  large  groups  of  brush-footed  butterflies,  some  of  whose  species 
occur  in  every  locahty,  are  the  fritillaries,  or  silver-spots  (genus  Argynnis 
and  allies)  and  the  checker-spots  (genus  Melitaea  and  allies).  The 
fritillaries,  mostly  medium-sized  to  large  butterflies,  are  usually  red-brown 
with  numerous  black  spots  scattered  over  the  upper  surface  of  both  wings; 
the  hind  wings  usually  bear  on  the  under  side  a  number  of  striking  silvery 
blotches,  which  give  these  butterflies  their  name  of  silver-spots.  The  regal 
fritillary,  Speyeria  idalia,  of  the  Atlantic  states,  expands  2f  to  4  inches  and 
has  the  fore  wings  bright  fulvous  above  spotted  with  black,  and  the  hind 
wings  blue-black  with  a  marginal  row  of  fulvous  and  submarginal  row 
of  cream-colored  spots;  both  fore  and  hind  wings  have  silver  blotches  on 
the  under  sides.  The  black,  ocher,  and  red-banded  caterpillars  have  six 
rows  of  fleshy  black  and  white  spines;  they  feed  on  violets  and  are  nocturnal. 
The  spangled  fritillary,  Argynnis  cyhele,  is  a  good  example  of  the  more 
usual  coloring  and  pattern  of  the  group.  It  expands  from  3  to  4  inches, 
has  both  wings  fulvous  above  and  thickly  spotted  with  black;  the  under 
side  of  the  hind  wings  is  silver-blotched;  in  the  female  the  basal  half  of 
the  fore  and  hind  wings  above  is  dark  chocolate-brown.  The  caterpillar 
is  black  with  six  rows  of  shining  black  branching  spines,  and  feeds  on  violets. 
Numerous  other  smaller  Argynnids  are  like  cybele  in  color  and  pattern: 
it  is  difficult  to  distinguish  the  various  species. 

The  checker-spots,  small  to  medium  size,  blackish  with  red  and  yellowish 
spots,  are  represented  by  numerous  species  in  the  western  mountain  states, 
but  by  only  two  species  in  the  east.  The  Baltimore,  Euphydryas  phaeton, 
expanding  if  to  2^  inches,  is  the  most  familiar  eastern  checker-spot;  it  is 
black  above  with  a  marginal  row  of  red  spots  followed  by  three  rows  of  pale- 


The  Moths  and  Butterflies  457 

yellow  spots  on  the  fore  wings  and  two  on  the  hind  wings;  besides  there 
are  some  scattered  red  spots  and  some  other  yellow  ones.  The  caterpillar 
is  black,  spiny,  and  banded  with  orange-red;  it  feeds  chiefly  on  Chelone 
glabera,  a  kind  of  snakehcad.  On  the  Pacific  coast  the  chalcedon, 
Melitaea  chalcedon,  is  the  most  abundant  checker-spot,  although  several 
other  species  are  common.  It  has  black  wings  spotted  with  red  and 
ocher-yellow;  the  spiny  black  caterpillar  feeds  chiefly  on  Mimulus  and 
Castilleja. 

The  satyrs  or  meadow-browns  are  a  group  of  fifty  or  more  beautiful  velvet- 
brown  butterflies  whose  markings  consist  chiefly  of  eye-spots,  large  and  small, 
on  both  upper  and  under  wing  surfaces.  A  number  of  species  are  abundant 
and  familiar,  but  a  majority  live  exclusively  in  mountain  states,  and  especially 
in  the  west.  The  common  wood-nymph,  or  eyed  grayling,  Cercyonis  dope, 
(PI.  X,  Fig.  i),  is  the  most  familiar  eastern  and  middle  state  species. 
A  larger  similarly  patterned  form,  C.  pegala,  is  common  in  the  south.  The 
larvae  of  the  meadow-browns  feed  on  grasses,  are  pale  green  or  light  brown, 
and  have  the  last  abdominal  segment  forked.  On  the  Pacific  coast  one 
of  the  most  abundant  autumn  butterflies  is  the  California  ringlet,  Cceno- 
nympha  calijornica,  a  small  buffy-white  member  of  this  group  with  small 
eye-spots  only  on  the  under  side  of  the  wings.  A  number  of  interesting 
butterflies  related  to  the  meadow-browns  are  found  only  on  mountain-tops 
or  in  high  latitudes  (arctic  region)  the  equivalent  in  Hfe  conditions  of  high 
altitudes.  In  the  Rocky  Mountains  on  the  peaks  of  the  Front  Range  (13,000 
feet  altitude)  I  have  struggled,  gasping  in  the  thin  air,  after  beautiful  frail 
little  brown  and  grayish  butterflies,  CEneis  and  Erebia.  Far  above  timber- 
line  on  bleak  mountain-tops,  masses  of  broken  granite  overspread  for  great 
spaces  with  lasting  snow,  these  hardy  little  flutterers  live  successfully.  At 
the  edges  of  the  great  snow-fields  are  patches  of  alpine  flowers,  fragrant 
dwarf  forget-me-nots  and  buttercups,  which  furnish  food  and  interest  for 
them  in  the  solitude  of  the  high  peaks. 

The  mountain-top  butterflies  of  the  White  Mountains,  of  the  Rocky 
Mountains,  and  of  the  Sierra  Nevada  are  closely  allied;  indeed  individuals 
of  the  same  species  are  found  on  the  summit  of  Mt.  Washington  and  on 
the  crest  of  the  Rockies,  and  nowhere  between  these  two  widely  separated 
localities.  The  question  as  to  how  this  interesting  condition  of  things  came 
about  would  be  answered  (by  the  student  of  distribution)  as  follows:  In 
glacial  times  the  species  probably  ranged  clear  across  the  continent.  With 
the  retreat  of  the  great  continental  ice-sheet,  while  most  of  the  butterflies 
followed  it  closely  north,  or  became  in  successive  generations  slowly  adapted 
to  the  temperate  life  conditions,  some  few  probably  followed  up  the  slowly 
retreating  local  mountain  glaciers.  In  time,  therefore,  the  descendants 
of  these  arctic-loving  species  found  themselves  still  under  truly  arctic  con- 


458 


The  Moths  and  Butterflies 


ditions  on  the  snow-covered  mountain-tops,  but  isolated  by  the  temperate 
lowlands  from  the  rest  of  their  kind  on  other  mountain-tops  or  in  arctic 
latitudes. 

There  are  several  excellent  books  about  American  butterflies  which  will 
help  the  nature  student  classify  his  specimens,  and  tell  him  of  the  distribution 
and  habits  of  the  various  species.  Among  the  best  are  Comstock's  "How 
to  Know  the  Butterflies,"  Holland's  "The  Butterfly  Book,"  and  Scudder's. 
' '  Everyday  Butterflies." 


P^^J5^F^ 


CHAPTER   XV 


THE      SAW  -  FLIES,     GALL  -  FLIES, 
ICHNEUMONS,     WASPS,     BEES, 

AND    ANTS    (Order  Hymenoptera) 

EES,  ants,  and  wasps  are  the  familiar  Hymenoptera. 
They  are  the  "intelhgent"  and  the  "social"  in- 
sects, and  therefore  seem,  of  all  the  insect  hosts,, 
those  living  the  most  speciaHzed  or  "highest"  kind 
of  life.  As  intelligence  and  social  life  are  precisely 
those  characteristics  of  our  own  which  most  dis- 
tinctly set  us  off  from  other  animals,  we  are  quick 
to  appreciate  the  worth  of  similar  attributes  in  the 
"ant  and  bee  people."  But  in  actual  degree  of 
specialization  of  instinct 
and  behavior  the  perform- 
ances of  the  soHtary  wasps 
and  bees  are  little  less  wonderful  than  those  of 
the  social  kinds,  and  the  amazing  character  of  the 
life-history  of  many  of  the  obscure  and  unfamiliar 
parasitic  and  gall-making  Hymenoptera  ought  to 
incite  as  much  interest  and  scientific  curiosity  as  the 
marvels  of  the  bee  community.  The  Hymenoptera 
constitute  a  large  order,  7500  species  in  this  coun- 
try, and  one  of  endless  variety  of  habit  and  struc- 
ture. Few  generalizations  indeed  can  be  made  that 
will  apply  to  all  the  members  of  the  order,  although 
there  is  no  question  concerning  the  true  relationship 

of  all  the  kinds  of  insects  included  in  the  order.     Of  ^^^-  645 --Mouth-parts  of  a 

honey-bee    with     maxilla 
the  structural  characteristics  common  to  the  Hymen-    and  mandible  of  right  side 

optera  the  clear,  membranous  condition  of  the  two    removed,    w J.,  mandible; 

.  .  .  mx.,  maxula.;  mx.p.,  max- 

pairs  of  wings  gives  the  name  to  the  order  {hymen,    juary  palpus;  mx.L,  max- 

membrane;  pteron,  wing).  The  front  wings  are  iHary  lobe;  st.,  stipes  of 
1  ^1  ^1  1  •  1  1  11  •  I  J  -^1  maxilla;  cJ.,  cardoof  max- 
larger  than  the  hind  ones,  and  all  are  provided  with  jjj^.  //.  labium-  sm.  sub- 
comparatively  few  branched  veins,  whose  homologies  mentum  of    labium;   m., 

have    not     been    fully   worked    out.     The    workers    "^^ntum  of  labium;  pg., 
•^  .  .  paraglossa;     gl.,      glossa; 

(infertile  females)  of  all  the  ant  species  are  wingless,    H.p.,  labial  palpus. 

459 


460 


Saw-flies,  Gall-flies,  Ichneumons, 


.as  are  also  the  females  of  the  Mutillid  wasps  and  a  few  other  exceptional 

forms.  In  many  Hymenoptera  (shown 


well  in  the  honey-bee)  the  fore 
(costal)  margin  of  the  hind  wings 
bears  a  series  of  small  but  strong 
recurved  hooks  which,  when  the 
wings  are  outspread,  fit  snugly  over 
a  ridge  along  the  hind  margin  of  the 
fore  wing,  the  two  wings  of  each  side 
being  thus  fastened  together  so  as  to 
move  synchronously.  A  structural 
characteristic  not  readily  made  out 
but  of  much  morphological  impor- 
tance is  the  complete  fusion  of  the 
Fig.  646.— Lateral  aspect  of  head  of  full-  true  first  abdominal  segment  with 
grown  larva  of  honey-bee  which  has  been  ^j^^  thoracic  mass,  SO  that  the  small 
cleared  so  as  to  show  the  forming  adult  head         ...  ,  , 

within,  ih.,  head  of  aduU;  i.e.,  compound  articulating  segment  between  what 
eye  of  adult;  Ic,  body-wall  of  larval  head;  ^^.g  called  thorax  and  abdomen  if 
i  ant.,  antenna  of  adult;  l.md.,  mandible  of         ,,       ,,  j        i_  j        •      1 

larva;    i.md.,   mandible   of  adult;    l.mx.,  really    the    second    abdominal    seg- 
maxilla  of  larva;    i.mx.,  maxilla   of  adult;  nient. 
l.li.,  labium  of  larva;  i.li.,  labium  of  adult. 


The  mouth-parts  are  variously 
modified,  but  usually  are  fitted  for  both  biting  and  sucking  (or  lapping). 
This  is  arranged  for  by  having  the  maxilla^  and 
labium  more  or  less  elongate  and  forming  a  sort 
of  proboscis  for  taking  up  liquids,  while  the  man- 
dibles always  retain  their  short,  strong,  toothed, 
jaw-like  character.  The  mandibles  of  the  honey- 
bee are  modified  into  admirable  little  "trowels" 
for  moulding  wax  and  propolis.  The  females 
throughout  the  order  are  provided  either  with  a 
saw-like  or  boring  or  pricking  ovipositor,  or  with 
the  same  parts  modified  to  be  a  sting.  The  sting 
is  possessed  by  the  wasps,  bees,  and  ants  (rudi- 
mentary in  many  ants),  on  which  account  these 
groups  are  often  referred  to  collectively  as  the 
aculeate  Hymenoptera.  The  sting  of  the  honey- 
bee is  shown  in  Fig.  650  and  is  a  well-developed 
example  of  this  characteristic  hymenopterous 
weapon  of  defence  and  offence.  The  barb-tipped 
darts  (d)  extend  down  through  the  sheath  (s)  and 
are  controlled  by  the  chitinous  bars  called  levers 
(/).      The   poison  produced  in  the   poison-gland   (p.gl.)  and  stored  in  the 


Fig.  647. — Mouth-parts  of 
mud-wasp,  with  mandible 
and  maxilla  of  right  side 
removed,  md.,  mandible; 
mx.,  maxilla;  mx.l.,  max- 
illary lobe;  inx.p.,  maxil- 
lary palpus;  //.,  labium; 
in.,  mentum  of  labium; 
pg.,  paraglossa;  gl.,  glossa; 
li.p.,  labial  palpus. 


PLATE   XII. 
WASPS   AND    BEES. 

1  =  Spharophthalraus  californicus. 

2  =  Polistes  aurifer. 
3=Stizus  sp. 
4=Psithyrus  elatus. 
5  =  Bomb  us  vagans. 
6=Agapostemon  radiata. 
7  =  Xylocopa  virginica. 
8=Bembex  spinolae. 
9=Vespa  germanica. 

io=  Bombus  californicus. 
11  =  Anthophora  pacifica. 
i2  =  Polybia  flavitarsis. 
i3=Chalybion  ccjeruleura. 
i4=Sphex  ichneunionea. 
15  =  Pelopeus  servilla- 


Ma^V  Wellni,<n.  del. 


Wasps,  Bees,  and  Ants 


461 


sac  (p.s.)  flows  from  this  into  lesser  reservoirs  in  the  expanded  base  of  the 
sheath  and  escapes  through  the  valve  (v)  along  the  darts 
into  the  wound.  The  tactile  (and  perhaps  olfactory)  palpi 
(p)  are  used  to  explore  the  surface  of  the  object  to  be 
stung.  The  modifications  of  the  various  appendage-like 
parts  which  compose  the  sting  to  form  an  egg-depositing 
organ  (ovipositor)  are  extremely  various  and  are  described 
later  in  connection  with  various  special  groups.  The 
number  of  separate  parts  or  processes  which  compose 
the  ovipositor  or  sting  and  which  arise  from  the  two  ab- 
dominal segments  next  in  front  of  the  terminal  one  is 
six,  and  some  entomologists  consider  these  parts  to  be  true 
appendages,  homologous  with  the  legs  and  mouth-parts. 
In  the  development  of  all  Hymenoptera  the  meta- 
morphosis is  complete,  and  the  larva?  are,  more  than 
in  any  other  order,  helpless  and  dependent  for  their 
food    and   safety   on   the   provision   or  care   of  the   parents 


"^  \mr.l. 
Fig.  64S. — Frontal  as- 
pect of  head  of  larva 
of  mud-wasp,  md., 
mandible;  mx.,  max- 
illa; mx.l.,  maxillary 
lobe;  //.,  labium; 
li.p.,  labial  palpus. 


With   many 


Fig. 


Fig.  649.  Fig.  650. 

649. — Lateral  aspect  of  head  of  full-grown  larva  of  mud-wasp  cleared  so  as  to 
show  forming  adult  head  within,  i.h.,  head  of  adult;  i.e.,  compound  eye  of  adult; 
I.e.,  body-wall  of  larval  head;  iant.,  antennae  of  adult;  l.md.,  mandible  of  larva; 
i.md.,  mandible  of  adult;  l.mx.,  maxilla  of  larva;  i.mx.,  maxilla  of  adult;  i.mx.p., 
maxillary  palpus  of  adult;  I. It.,  labium  of  larva;  i.li.,  labium  of  adult;  li.lip.,  labial 
palpus  of  adult. 
Fig.  650. — Sting  of  the  worker  honey-1  ee.  p-gl.,  poison-gland;  p.s.,  poison-sac;  d.,  dart; 
/.,  levers;    v.,  valve;    s.,  sheath;    p.,  palpus. 


species,  as  the  solitary  wasps  and  bees,  food  is  stored  up  in  the  cell  in  which. 


462  Saw-flies,  Gall-flies,  Ichneumons, 

the  egg  is  deposited,  so  that  the  larva  on  hatching  will  find  it  ready  to  hand. 
With  the  social  wasps  and  bees  and  all  the  ants,  the  workers  bring  food  to 
the  larva  during  its  whole  life.  With  the  lower  forms,  the  parasitic  and 
gall-making  kinds,  the  egg  is  deposited  on  or  in  a  special  and  suflScient  food- 
supply.  All  these  unusual  conditions  are  described  in  the  discussion  of 
the  various  groups.  Indeed  this  whole  chapter  on  the  Hymenoptera  is  writ- 
ten especially  with  the  aim  of  illustrating  the  biology,  the  special  life  con- 
ditions and  relations  of  the  various  larger  groups  of  these  insects,  rather 
than  with  the  aim  which  determined  the  character  of  the  chapters  on  the 
beetles  (Coleoptera)  and  moths  and  butterflies  (Lepidoptera),  namely,  that 
of  presenting  a  systematic  survey  of  the  classification  and  individual  habits 
of  those  members  of  the  order  most  likely  to  be  seen  or  captured  by  the  col- 
lector. The  beetles  and  the  moths  and  the  butterflies  are  the  insects  which 
fill  the  cabinets  of  the  amateur  and  beginning  student,  and  names  and  facts 
concerning  particular  species  are  likely  to  be  the  particular  desiderata  in 
connection  with  them.  But  it  is  the  extraordinary  and  "wonderful"  char- 
acter of  the  ecological  relations  and  physiological  adaptations  of  the  Hymen- 
optera which  make  these  insects  of  such  interest  to  nature-lovers,  and  which, 
indeed,  is  the  subject  that  can  most  profitably  be  given  special  attention 
by  any  student  of  the  order.  Without,  therefore,  making  any  further  attempt 
to  formulate  generalizations  concerning  this  great  complex  of  variously 
mannered  insects,  we  may  begin  our  study  of  its  members  arranged  in  sub- 
ordinate groups,  this  grouping  depending  rather  upon  general  biologic  char- 
acteristics than  strictly  classific  ones. 

The  classification  of  the  Hymenoptera  is  a  matter  that  interests  but  few 
amateurs;  only  a  few  families  are  at  all  well  represented  in  general  collec- 
tions. Distinction  among  the  more  familiar  larger  groups,  as  the  ants,  bees, 
wasps,  saw-flies,  horn-tails,  and  ichneumons,  is  usually  pretty  well  marked 
in  the  general  habitus  or  tout  ensemble  of  appearance.  Certain  other  of  the 
larger  groups,  composed  of  minute  parasitic  species,  are  almost  unknown 
to  the  general  collector;  indeed  but  two  or  three  American  professional 
entomologists  would  attempt  to  distinguish  species  in  these  groups.  In  the 
following  table,  therefore,  and  in  the  later  discussion  of  the  various  groups, 
I  have  lumped  these  little-known  families  together  on  a  basis  of  common- 
ness of  habit,  namely,  of  parasitic  life,  and  devoted  the  space  to  a  general 
account  of  the  extraordinary  life-history  and  habits  which  these  parasitic 
Hymenoptera  have  adopted,  with  some  reference  to  the  special  habits  of 
certain  particular  species.  Their  classification  into  smaller  groups  is  left 
undiscussed. 


Wasps,  Bees,  and  Ants  463 


KEY  TO  GROUPS  OF  HYMENOPTERA. 

A.      Trochanters   (segment  between  the  rounded  basal  coxa  and  the   long  femur)   of 
the  hind  legs  divided  in  two,  i.e.,  two-segmented;    female  with  a  saw  or   borer   at 
tip  of  body  for  depositing  the  eggs. 
B.      Abdomen  joined  broadly  to  the  thorax. 

C.      Tibiae  of  fore  legs  with  two  apical  spurs;    female  with  a  pair  of  saw-like 
egg-depositing  processes  at  tip  of  abdomen. 

(Saw-flies.)     Family  Tenthredinid^  (p.  464). 
CC.  Tibias  of  fore   legs  with  one   apical  spur;    female  with  elongate   borer 

instead  of  saw (Horn-tails.)     Family  SlRlciD^  (p.  466). 

BB.  Base  of  abdomen  constricted,  so  that  it  joins  the  thorax  as  if  by  a  stem. 
C.      Abdomen  joined  to  the  dorsum  of  the  metathorax. 

(Ensign-flies.)     Family  Evaniid^. 
CC.  Abdomen  joined  to   posterior  aspect  of  metathorax. 

D.      Fore  wings  with  few  veins  and  no  closed  cells  (a  few  exceptions); 
very  small  parasitic   Hymenoptera. 

Families  Chalcidid^  and  Proctotrypid^  (p.  476). 
DD.  Fore  wings  with  one  or  more  closed  cells  (a  few  exceptions). 
E.      Fore  wings  without  a  stigma  (Fig.  655). 

(Gall-flies.)     Family  Cynipid^  (p.  467). 
EE.  Fore   wings  with    a    stigma  (Fig.  671);     parasitic  Hymenop- 
tera, from  very  small  to  large. 

(The  Ichneumons  and  other  parasites.)     Families   Braco- 
NiD^,  Stephanid.e,  Ichneumonid^,  and  Trigonalid^  (p.  476). 
AA.  Trochanters  of  hind  legs  not  divided,  i.e.,  consisting  of  a  single  segment;    female 
often  with  a  sting. 
B.      Fore  wings  with  no  closed  submarginal  cells  (Fig.  683). 

C.      Abdomen  long  and  slender,  and  antennae  also  long  and  filiform. 

Family  Pelecinid^  (p.  484). 
CC.  Abdomen  short,  but  little  longer  than  head  and  thorax;    antennae  short 

and  elbowed (Cuckoo-flies.)     Family  Chrysidid^  (p.  498). 

BB.  Fore  wings  with  at  least  one  closed  submarginal  cell. 

C.      First  abdominal  segment  and  sometimes  the  second  segment  in  the  shape  of 
a  small  disk-like  piece  (Fig.   743). 

(Ants.)     Superfamily  Formicina  (p.  533). 
CC.  Basal  segment  (or  segments)  of  abdomen  normal  or  elongated  to  form 
a  peduncle. 

D.      First  segment  of  tarsus  of  hind  legs  cylindrical  and  naked  or  with 
but  little  hair. 
E.      Wings  not  folded  longitudinally  when  at  rest. 

(Digger-wasps.)     Superfamily  Sphecina  (p.  490). 
EE.  Wings  folded  longitudinally  when   at  rest. 

(True  wasps.)     Superfamily  Vespina  (p.  503). 
DD.  First  segment  of  tarsus  of  hind  legs  expanded  and  flattened  and 
furnished  with  numerous  hairs,  some  rather  long. 

(Bees.)     Superfamily  Apina  (p    510). 

According  to  Ashmead  our  foremost  American  student  of  the  classification 
of  Hymenoptera,  the  above  table  gives  in  some  respects  false  indications  of 


464  Saw-flies,  Gall-flies,  Ichneumons, 

relationship.  For  example,  the  Proctotrypiclie  are  held  by  Ashmead  to  be 
more  nearly  truly  related  to  the  wasps  and  to  the  gall-flies  (Cynipidae)  than  to 
the  other  parasitic  Hymenoptera,  as  the  Chalcididae,  Braconidae,  and  Ichneu- 
monidae,  with  which  this  table  groups  them.  The  families  composing  the 
superfamilies  Sphecina  and  Vespina,  as  separated  by  the  character  used 
in  the  key,  are  differently  divided  in  Ashmead's  superfamilies  Sphecoidea 
and  Vespoidea,  and  the  families  Tenthredinidae  and  Siricidae  are  replaced 
by  the  superfamilies  Tenthredinidoidea  and  Siricicoidea,  each  containing 
several  families.  I  only  need  to  repeat  what  I  have  often  said  before,  namely, 
that  at  best  the  keys  and  tables  used  in  this  book,  as  in  most  other  insect  manu- 
als, to  assist  the  student  in  his  work  of  classifying  insects  are  primarily  things 
of  convenience,  taking  advantage  of  obvious  but  often  superficial  and  adapt- 
ively  acquired  likenesses  and  differences,  rather  than  attempts  to  offer  a 
true  genealogical  arrangement  of  the  various  groups. 

The  saw-flies,  Tenthredinidae,  are  the  simplest  Hymenoptera;  they  show 
no  such  extreme  specialization  in  habit  or  structure  as  that  possessed 
by  the  host  of  parasitic  species,  or  by  the  "intelligent"  groups,  the  ants, 
bees,  and  wasps.  They  compose  a  large  family,  600  species  being  known 
in  this  country,  but  one  of  singular  unity.  The  adults  are  much  ahke  in 
appearance,  and  the  larvae  all  agree  in  their  salient  characters  of  structure 
and  habit.  Despite  the  large  number  of  our  species,  comparatively  few 
are  known  to  the  general  observer,  and  these  almost  solely  because  of  the 

injurious  habits  of  their  larvae.  These  larvae 
are  the  familiar  rose-,  currant-,  pear-,  larch-, 
and  willow-slugs.  They  are  soft  bodied, 
naked,  slug-like  or  caterpillar-Iike  creatures, 
usually  with  six  to  eight  pairs  of  prop-legs 
besides  the  three  pairs  of  true  thoracic  legs, 
and  are  voracious  devourers  of  green  leaves. 
They  may  be  distinguished  from  lepidopterous 
larvae  by  their  usual  possession  of  more  than 
five  pairs  of  prop-legs  and  by  their  having 
but  a  single  ocellus  on  each  side  of  the  head 
Fig.  651.— a  saw-fly,  Allantus  instea,d  of  several.  The  eggs  are  laid  by  the 
hasillaris.  (Twice  natural  size.)  females  in  little  pockets  cut  in  tender  stems  or 
in  the  leaf-tissue,  usually  on  the  under  side,  by  means  of  the  famous  "saws" 
which  have  given  the  insects  their  vernacular  name.  These  saws  are  a  pair 
of  small  slightly  chitinous  pieces,  finely  serrate  on  the  outer  margins,  which 
are  carried  by  the  last  abdominal  segment  and  can  be  thrust  out  and  moved, 
saw-like,  up  and  down.  The  larvae,  or  slugs  as  they  are  often  called 
because  of  their  shape  and  the  slimy  secretion  which  covers  the  body  of  some 
kinds,  usually  "skeletonize"  the  leaves,  i.e.,  eat  away  only  the  soft  tissues. 


Wasps,  Bees,  and  Ants 


465 


leaving  the  skeleton  of  tough,  fibrous  veins;  often  only  the  upper  surface 
of  the  leaf  is  fed  on.  Some  of  them  cover  the  body  with  a  white,  waxy  secre- 
tion, and  some,  when  disturbed,  emit  a 
malodorous  fluid  from  the  mouth  or  from 
pores  in  the  skin.  When  full-grown,  they 
crawl  down  to  the  ground,  burrow  into  it,  and 
pupate  within  a  little  cell  sometimes  lined 
with  a  thin  silken  cocoon.     Some  of  the  larvae  ^       ,         ,^,  ,       , 

.  ,,         ,  •   ,      ,        1  u      4.  4.U  ^^'^-  (^52-— The  currant-sluf^,  larva 

live  in  gall    which  develop  about  them;  one  of  the  currant  saw-fly,  Nematus 

such    species    is    common   on    willows.      The  ventricosus.      (Two  and  one-half 

11,  .11  xi  i_        J  u    i  times  natural  size.) 

adults  mostly  have    rather    broad    somewhat 

flattened  bodies  and  head,  are  quietly  colored,  blackish,  reddish,  brownish, 
and  usually  quietly  mannered,  but  fluttering  about  in  the  trees  at  egg-lay- 
ing time. 

It  has  been  noted  that  numerous  species  of  saw-flies  can  produce  young 


Fig.  653. — The  currant-stem  girdler,  Janus  integer,  a  saw-fly  at  work  girdling  a  stem 
after  having  deposited  an  egg  in  the  stem  half  an  inch  lower  down.  (Photograph 
by  Slingerland;    natural  size.) 


from  unfertilized  eggs  (parthenogenetic  reproduction),  and  in  some  species 


466  Saw-flies,  Gall-flies,  Ichneumons, 

no  males  have  yet  been  discovered.  It  is  indeed  a  general  rule  in  the  family 
that  the  females  greatly  outnumber  the  males. 

Probably  our  most  familiar  saw-fly,  at  least  in  its  larval  stage,  is  the 
rose-slug,  Monostegia  roses,  a  soft-bodied,  greenish-yellow,  nocturnal  larva 
that  skeletonizes  rose-leaves  and  often  occurs  in  such  numbers  as  practically 
to  defoliate  the  bushes.  The  adult  fly  is  black  with  sooty  wings  and  whitish 
fore  and  middle  legs.  There  are  two  generations  a  year.  Two  currant- 
slugs  are  common:  one  the  imported  currant-worm,  Nematus  ventncosus 
(Fig.  652),  green  with  many  small  black  spots  (in  its  last  stage  only  the  head 
is  black-spotted);  the  other  the  native  currant-worm,  Pristophora  grossii- 
lari(E,  all  pale  green  except  the  blackish  head,  which  becomes  partly  green 
just  before  pupation.  Both  of  these  slugs  make  slight  cocoons  of  silk  and 
leaves  in  which  to  pupate,  the  first-named  one  in  or  on  the  ground,  the  second 
one  attached  to  the  twigs  or  leaves  of  the  currant-bush. 

The  pear-tree  slug,  Eriocampa  cerasi,  is  half  an  inch  long  when  full-grown, 
with  the  body  expanded  in  front  so  as  to  be  almost  tadpole-shaped;  it  is 
greenish  with  a  gummy  slime  over  it.  It  feeds  in  May  and  June  on  the 
upper  surfaces  of  the  leaves,  and  when  full-grown  crawls  down  to  the  ground 
and  makes  a  little  cell  just  below  the  surface  in  which  to  pupate.  The 
winged  saw-fly  is  glossy  black,  about  ^  inch  long.  The  eggs  are  laid  in 
slits  cut  on  the  under  side  of  the  leaves.  The  larch  is  often  seriously  attacked 
by  the  larva  of  the  saw-fly  Nematus  erichsonii;  it  is  a  glaucous  green  slug 
with  jet-black  head  and  two  double  rows  of  tiny  black  points  around  the 
abdomen;  it  is  -|  inch  long  and  has  seven  pairs  of  prop-legs.  The  adult, 
■|  inch  long,  is  thick-bodied,  blackish  with  a  broad  bright  resin-red  band  on 
the  abdomen.  The  eggs  are  laid  in  the  young  shoots  in  June  or  July,  the 
larvae  feeding  until  late  in  July  or  early  in  August.  In  California  one  of 
the  most  abundant  saw-flies  is  a  species  of  Lyda,  which  lays  its  eggs  in  the 
svmimer  on  the  new  growth  of  needles  on  pines.  The  larvae  hatch  out 
in  fifteen  days  and  feed  on  the  needles  for  four  months;  then  they  trans- 
form to  another  larval  stage,  migrate  to  the  tops  of  the  trees,  and  just 
before  winter  spin  a  silken  cocoon  in  which  they  pupate.  The  adult  flies 
issue  in  the  spring. 

A  much  smaller  family  than  that  of  the  saw-flies  is  the  nearly  related 
one  of  the  horntails,  the  Siricidae.  About  fifty  species  are  known  in  this 
country.  The  females  are  provided  with  a  boring  ovipositor,  which  appears 
as  a  conspicuous,  strong,  long  "horn,"  projecting  from  the  tip  of  the  abdo- 
men; Comstock  describes  this  ovipositor  as  composed  of  five  long  slender 
pieces;  the  two  outside  pieces  are  grouped  on  the  inner  surface,  and  when 
joined  make  a  sheath  containing  the  other  three  pieces,  two  of  which  are 
furnished  at  the  tip  with  fine  transverse  ridges  like  the  teeth  of  a  file.  With 
this  boring  ovipositor  the  female  can  drill  holes  into  the  solid  wood  of  a  tree 


Wasps,  Bees,  and  Ants 


467 


Fig.  654. — The  pigeon-tremex,  Tremex 
columba.  (After  Jordan  and  Kellogg; 
natural  size.) 


and  place  an  egg  at  the  bottom  of  each.  Ojae  of  the  best-known  horntails 
is  the  pigeon-tremex,  Treynex  columba  (Fig.  654),  i^  inches  long,  with  reddish 
head  and  thorax  and  black  abdomen  with  yellow  bands  and  spots  along 
the  sides.  The  females  bore  holes  J 
inch  deep  into  elms,  oaks,  sycamore- 
or  maple-trees,  the  ovipositor,  in  boring, 
being  held  bent  at  right  angles  with 
the  abdomen.  The  larvae  hatching 
from  the  eggs  laid,  one  in  each  hole, 
burrow  into  the  heart-wood  of  the 
tree,  and  grow  to  be  cylindrical,  blunt- 
ended,  whitish  grubs,  i^  inches  long, 
with  short  thoracic  legs  and  a  short  anal 
horn.  They  pupate  in  their  burrows 
within  a  cocoon  made  of  silk  and  tiny 
chips.  The  issuing  winged  adult  gnaws 
its  way  out  through  the  bark.  In 
some  allied  species  (Sirex)  the  pupa  may  remain  in  the  tree  for  several 
years.  Tremex  is  parasitized  by  an  extraordinary  ichneumon-fly,  Thalessa, 
which  has  a  slender,  flexible  ovipositor,  four  to  five  inches  long,  with  which 
it  bores  into  trees  infested  by  Tremex  and  deposits  its  eggs  in  the  Tremex- 
burrows.  The  young  Thalessa-grub  (larva)  moves  along  the  burrow  until 
it  finds  a  Tremex-larva,  to  which  it  attaches  itself,  living  parasitically.  (See 
account  of  Thalessa,  p.  483.)  A  small  horntail  sometimes  abundant  and 
injurious  is  the  European  grain-cephus,  Cephus  pygmcBUs,  whose  larvae 
bore  into  wheat-stems.  The  adult  is  f  inch  long,  shining-black-banded  and 
spotted  with  yellow.  It  lays  its  eggs  in  tiny  holes  bored  in  the  stems  just 
about  the  time  of  the  forming  of  the  heads;  the  larvas  tunnel  down  through 
the  stem,  reaching  the  lowest  part  of  the  straw  about  harvest-time.  This 
part  is  left  by  the  reaper,  and  in  it  the  larva  makes  a  silken  cocoon  within 
which  it  hibernates.  In -March  or  April  it  pupates,  and  the  adult  issues 
in  May. 

Indications  of  the  work  of  certain  hymenopterous  insects  are  familiar  to 
■even  the  most  casual  observers  in  the  variously  shaped  "galls"  that  occur 
on  many  kinds  of  trees  and  smaller  plants,  especially  abundantly,  however, 
on  oaks  and  rose-bushes.  Not  all  galls  on  plants  are  produced  by  insects, 
certain  kinds  of  fungi  giving  rise  to  gall-like  malformations  on  plants,  nor 
are  all  the  insect  galls  produced  by  members  of  that  family  of  small  hymen- 
opterous insects  called  the  Cynipidae,  or  gall-flies.  But  most  of  the  closed 
plant-galls,  and  particularly  those  conspicuous,  variously  shaped,  and  most 
familiar  ones  found  abundantly  on  oak-trees  and  rose-bushes,  are  abnormal 
growths  due  to  the  irritation  of  the  plant-tissue  by  the  minute  larvae  of  the 


468 


Saw-flies,  Gall-flies,  Ichneumons, 


Cynipid  gall-flies.     These  flies   (Fig.   655)   are  all  very  smaU,   the  largest 

species  not  being  more  than  ^  inch  long; 
they  are  short-bodied  and  have  in  most 
cases  four  clear  wings  with  few  veins. 
The  females — and  in  numerous  species 
there  seem  to  be  no  males — have  a  long, 
slender,  and  flexible  but  strong,  sharp- 
pointed  ovipositor  (Fig.  656),  composed  of 
several  needle-  or  awl-like  pieces,  which 
is  used  to  prick  (pierce)  the  soft  tissue  of 
leaf  or  tender  twig  so  that  an  egg  may  be 
deposited  in  this  succulent  growing  plant- 
tissue. 

Each  female  thus  inserts  into  leaves  or 
twigs  many  eggs,  perhaps  but  two  or  three 
in  one  leaf  or  stem  if  the  galls  are  going 
to  be  large  ones,  or  perhaps  a  score  or  so  if 
the  galls  will  be  so  small  as  to  draw  but  little  on  the  plant-stores  and 
be  capable  of  crowding.  In  two  or  three  weeks  the  egg  gives  birth  to 
a  tiny  footless  maggot-like  white  larva  which  feeds,  undoubtedly  largely 
through  the  skin,  on  the  sap  abundantly  flowing  to  the  growing  tissue  in 
which  it  lies.     With  the  birth  of  the  larva  begins  the  development  of  the 


Fig.  655. — A  gall-fly,  species  unde- 
termined.    (Much  enlarged.) 


Fig.  656. — Ovipositor  of  a  gall-fly,  dorsal  and  lateral  views;    the  long  tapering  part  is 
the  piercing  portion;   the  other  parts  constitute  levers  and  supports      (After  Lacaze-' 
Duthiers;    greatly  magnified.) 


gall,  which  is  an  abnormal  or  hypertrophied  growth  of  tissue  about  the  point 
at  which  the  larva  lies.  The  excitation  or  stimulus  for  the  growth  undoubtedly 
comes  from  the  larva  and  probably  consists  of  irritating  special  salivary 
excretions  and  perhaps  also  of  physical  irritation  caused  by  the  presence 


Wasps,  Bees,  and  Ants 


469 


of  the  wriggling  body.  In  some  species  the  gall  grows  around  and  includes 
but  a  single  larva,  in  others  around  several  to  many.  The  larva  reaches  its 
full  development  about  coincidently  with  the 
full  growth  or  end  of  the  vitality  of  the  gall, 
this  period  varying  mucli  with  different  galls. 
In  the  galls  on  deciduous  leaves  the  vitality 
is  shortest,  ending  in  autumn;  in  twig-galls 
it  may  not  end  until  winter  or  even  until  the 
following  or  indeed  the  second  winter.  When 
'"dead"  the  gall  dries  and  hardens,  thus  form- 
ing a  firm  protecting  chamber  in  which  the  larva 
or  larvaj  pupate.  The  pupa  undergoes  its  non- 
food-taking life  securely  housed  in  the  dry  gall, 
which  may  fall  with  the  autumn  leaves  or  cling 
to  the  bare  twigs.  From  the  galls  the  fully 
developed  flies  gnaw  their  way  out  when  new 
leaves  and  tender  shoots  are  appearing,  ready 
to  prick  in  new  eggs  for  another  life  cycle. 

But,  strange  to  say,  with  some  species 
the  new  eggs  may  be  deposited  on  plants  of 
another  kind  and  the  hatching  larvae  stimulate 
the  growth  of  entirely  different-shaped  galls, 
and  they  themselves  develop  into  gall-flies 
of  markedly  different  appearance  from  their 
mothers.  These  new  gall-flies  in  their  turn  lay 
eggs  on  the  first  host-plant;  the  forming  galls 
are  like  those  of  the  grandparent  generation 
and  the  fully  developed  flies  are  of  the  grand- 
parent kind.     This  alternation  of  generations — 

a  condition  in  which  a  single  species  appears  in  two  forms  and  produces 
two  kinds  of  galls,  usually  on  different  host-plants — has  been  long  known, 
but  still  remains  a  problem  which  interferes  sadly  with  a  number  of  popular 
biological  generalizations.  One  of  these  generations  appears  exclusively  in 
only  one  sex,  the  female,  so  that  the  other  generation,  composed  of  both 
males  and  females,  is  produced  uniformly  from  unfertilized  eggs.  The 
adults  and  galls  of  the  two  generations  were  formerly  described  as  belong- 
ing to  two  different  Cynipid  species.  Not  all  gall-flies,  however,  show  this 
dimorphic  condition;  some  appear  habitually  in  but  one  form  and  pro- 
duce but  one  kind  of  gall;  in  most  if  not  all  of  these  cases  the  species  is 
represented  only  by  female  individuals. 

The  great  variety  of  the  galls,  the  extraordinary  instinct  which  leads  the 
adult  flies  to  the  right  selection  of  plant  and  position  on  twig  or  leaf  for  ovi- 


FlG.  657. — Galls  made  by  a 
Cynipid  gall-fly.  (Natural 
size.) 


470 


Saw-flies,  Gall-flies,  Ichneumons, 


position,  and  the  interesting  response  or  reaction  of  the  plant  to  the  growth- 
stimulating  irritation  of  the  gall-fly  larva  are  subjects  which  have  attracted 
much  attention  and  study,  but  concerning  which  much  remains  to  be  dis- 
covered. In  size  and  shape  the  galls  present  amazing  variety;  some  are  irreg- 
ular little  sweUings  on  the  leaves,  others  are  like  small  trumpets,  others  like 

rosettes  or  star-like  with  radiating 
points;  on  the  twigs  some  are  spherical, 
some  elongate,  and  some  large  and 
reniform.  Figs.  657  to  665  show 
r  >y  ^  R_^  something      of 

this  variety. 
In  their  interior 
make-up  they 
also  differ 
much ;  some 
have  a  large 
hollow  central 
space ;       some 


Fig.  658.  Fig.  659. 

Fig.  658.— Galls  on   leaf  of   California  white  oak.     (Natural"^ 

size.) 
Fig.  659.— Trumpet-galls  on  leaves  of  California  white  oak. 

(Natural  size.) 

are  filled  with  open,  spongy  tissue,  and  some  are 
solid  except  for  the  cells  and  tunnels  of  the  larvae. 
In  some  but  a  single  larva  lives;  in  others  are  three 
or  four  or  a  dozen.  Externally  some  are  smooth, 
some  roughened,  some  hairy.  They  occur  on  leaves, 
branches,  and  roots  in  both  oak  and  rose.  Only  Fig.  660.— Galls  on  leaf 
a  few  Cynipid  galls  are  known  on  other  plants  ^J^^^S'sizeO^'"'  °^^' 
than  these.    In  the  face  of  the  host  of  species  of  Cyni- 

pidjE  found  in  this  country— over  200  gall-making  kinds  are  known,  besides 
a  score  of  parasitic  species— and  their  small  size  and  generally  similar  appear- 
ance, we  shall  not  undertake  to  describe  any  of  the  various  species.  Corn- 
stock  describes  in  his  Manual  several  of  the  more  common  eastern  galls,  or 


Wasps,  Bees,  and  Ants 


471 


"oak-apples."     One   of   these   is  the  fibrous  oak-apple  of  the  scarlet  oak, 
I  to  2  inches  in  diameter,  produced  by  the  gall-fly  Aniphiholips  coccinece. 


Fig.  661. — Galls  on  leaf  of  California  white  oak.     (Natural  size.) 

This  gall  is  distinguished  by  having  a  small  hollow  kernel  in  the  center  of 
the    gall,    in    which 
the  single  larva  lives, 
the     space    between 
the    kernel    and   the 
dense  outer  layer  of 
the  gall  being  filled 
with  fibers  radiating 
out    to    the    surface 
from  the  kernel.  The 
spongy  gall  of  the  red 
and  bjack  oak,  made 
by  Am phiboli ps 
spongifica,    has     the 
space  between  kernel 
and  outer  wall  filled 
by  a  porous,  spongy 
mass.    In  the  "emp- 
ty  oak-apples,"    the 
larger     one    of     the 
scarlet  and  red  oaks, 
Holcaspis   inanis,   2 
inches    or    more    in 
'  diameter,    and     the 
smaller,  of  the  post- 
oak,  H.  cent r kola,  | 
inch  or  less  in  diam- 
eter,   the    space   be- 
tween    kernel     and 
outer  wall    contains 
only  a  few  slender  silky  filaments  which  suspend  the  kernel  in  place 


Fig.  663.  Fia.  662. 

Fig.  662.— Galls  on  twigs  of  California  white  oak;  upper  figure, 

a  gall  split  open  longitudinally.     (Natural  size.) 
Fig.  663.— Galls  on  leaf.     (After  Jordan  and  KeUogg;  natural 

size.) 

The 


472 


Saw-flies,  Gall-flies,  Ichneumons, 


common  bullet  gall,  H.  globulus,  of  the  small  twigs,  |  to  f  inch  in  diam- 
eter, has  the  kernel  surrounded  by  a  hard  woody  substance. 


I-'IG.  664. — An  oak-apple,  or  fibrous  gall  of  the  Calilornia  live-oak;  in  upper  figure  the 
gall  shown  in  position  on  the  oak-twig;  in  lower,  a  gall  cut  open  to  show  the  inside. 
(Upper  figure  slightly  reduced;    lower  figure  natural  size.) 


In  California  the  white  or  valley  oaks  bear  very  commonly  conspicuous 
large  white  spherical  to  kidney-shaped  galls  (Fig.  665)  which  are  attached 
to  the  branches,  and  often  occur  in  such  abundance  as  to  make  the  injured 
tree  look  like  some  new  kind  of  fruit-tree  in  heavy  bearing.  This  gall  is 
caused  by  the  gall-fly  Andriciis  calijornicus,  one  of  the  largest  of  the  Cyni- 
pidae,  and  the  gall  itself  attains  a  larger  size  than  any  other  known  to  me. 
It  begins  as  an  elongate  swelling  underneath  the  bark  of  the  fresh  twigs, 
but  soon  breaks  through  as  a  shining,  smooth  excrescence  rapidly  increasing 
in  size.  A  single  gall  is  inhabited  by  from  six  to  a  dozen  larvae.  A  curious 
oak-leaf  gall  is  the  jumping  seed-gall  (Fig.  666),  a  small  and  shot-like  gall  which 


Wasps,  Bees,  and  Ants  473 

develops  on  the  leaf,  but  which  after  reaching  full  growth  falls  oflf,  when  the 


Fig.  665. — The  giant  gall  of  the  California  white  oak,  produced  by  Andricus  calijornicus; 
at  right  a  gall  cut  open  to  show  inside  structure.  (After  Jordan  and  Kellogg;  one- 
half  natural  size.) 

wriggling  of  the  still  active  larva  within  causes  it  to  roll  about  or  even  spring 
a  quarter  of  an  inch  or  more  into  the  air. 

Of  the  rose-galls  Comstock  mentions 
the  mossy  rose-gall,  produced  by  Rhodites 
rosce,  as  a  very  common  one  on  the  sweet- 
brier.  It  consists  of  a  large  number  of 
hard  kernels  surrounding  the  branch  and 
covered  with  reddish  or  green  mossy 
filaments.  In  each  kernel  is  a  larva. 
The  pith  blackberry  -  gall,  Diastrophus 
nehulosus,  is  a  common,  many-chambered, 
large,  woody  gall  that  occurs  on  black- 
berry -  canes.  It  attains  a  length  of  3 
inches  and  a  width  of  i  inch  to  ij  inches. 

Regarding  the  wonderful  instinct  of 
the  gall-fly,  I  quote  the  following  from 
Stratton,  an  English  student  of  galls: 

"It  is  impossible   that    inteUigence  or 

memory  can  be  of  any  use  in  guiding  the 

Cynipidae;   no  Cynips  ever  sees  its  young, 

and  none  ever  pricks  buds  a  second  season, 

or  lives    to    know   the  results  that  follow    Fig.  666.— Jumping  galls  of  the  oak 

.  produced    bv  Cynips    quercus-saL' 

the  act.     Natural  selection  alone  has  pre-       tatrix.    (Galls  on   leaf  of  natural 

size ;     at   left 

11  •  r     r  •    ,  ,  enlarged.) 

seasonally   recurrmg     feelmgs,    sights,    or 


single    gall   much 


served  an  impulse  which  is  released  by 
seasonally  recurring  feelings,  sights,  or 
smells,  and    by    the    simultaneous    ripening    of    the    eggs  within    the    fly. 


474 


Saw-flies,  Gall-flies,  Ichneumons, 


Fig.  667. — Cynips  qiiercus- 
sallatrix,  the  gall  -  fly 
which  produces  the 
jumping  galls.  (Much 
enlarged.) 


These  set  the  whole  physiological  apparatus  in  motion,  and  secure  the 
insertion  of  eggs  at  the  right  time  and  in  the  right  place.  The  number 
of  eggs  placed  is  instinctively  proportionate  to 
the  space  suitable  for  oviposition,  to  the  size  of 
the  fully  grown  galls,  and  to  the  food-supplies 
available  for  their  nutrition.  Dryophanta  scutellaris 
will  only  place  from  one  to  six  eggs  on  a  leaf  which 
Neuroteriis  lenticiilaris  would  probably  prick  a 
hundred  times." 

"Whatever  form  the  gall  takes,  the  poten- 
tialities of  the  tissue-growth  exhibited  by  it  must 
be  present  at  the  spot  pricked  by  the  fly." 

"The  potentialities  of  growth  being  present,  they 
are  called  into  activity  by  the  larva,  a  result  advan- 
tageous to  the  larva  and  sometimes  described  as 
disinterested  and  self-sacrificing  on  the  part  of  the 
plant.  We  have  just  seen  that,  so  far  as  the  larva 
is  concerned,  the  peculiar  structures  of  the  gall 
owe  their  origin  to  their  success  in  feeding  and  defending  it;  and,  so  far  as 
the  plant  is  concerned,  these  structures  have  been  evolved  in  consequence 
of  their  value  in  enabling  the  plant  to  repair  injuries  in  general,  and  the 
injuries  inflicted  by  larvae  in  particular.  If  John  Doe  raises  a  cane  to  strike 
Richard  Roe,  and  Richard  throws  up  his  arms  intuitively  to  parry  the  stroke, 
the  action  does  not  indicate  a  prophetic  arrangement  of  molecules  to  fru.strate 
John  in  particular,  but  an  inherited  action  of  defence.  The  first  act  of  an 
injured  plant  is  to  throw  out  a  blastem,  and  only  those  larvae  survive  to  hand 
down  their  art  which  emerge  from  an  egg  so  cunningly  placed  as  to  excite  the 
growth  of  a  nutritive  blastem.  It  is  not  always  possible  to  keep  the  besiegers 
from  using  the  waters  of  the  moat,  although  there  is  no  disinterested  thought 
of  the  besiegers'  wants  when  the  ditches  are  planned.  So  in  the  war-game 
that  goes  on  between  insect  and  plant,  natural  selection  directs  the  moves 
of  both  players,  but  there  is  nothing  generous  or  altruistic  on  either  side." 

The  exact  character  of  the  plant's  abnormal  growth  has  been  recently 
studied  by  several  investigators.  Cook,  an  American  student,  concludes 
from  his  studies  that  in  the  formation  of  all  leaf-galls  (except  the  Cecidomyid 
or  dipterous  midge-galls)  the  normal  cell-structure  of  the  leaf  is  first  modi- 
fied by  the  formation  of  a  large  number  of  small,  compact,  irregular-shaped 
cells.  The  mesophyll  is  subject  to  the  greatest  modification  and  many  small 
fibro-vascular  bundle:;  form  in  this  modified  mesophyll.  Both  Adler  and 
Sockeu  consider  that  after  the  first  stages  of  formation  the  gall  becomes  an 
independent  organism  growing  upon  the  host-plant.  Cook  believes  this 
to  be  true  of  the  Cynipid  galls.     A  surprising  conclusion  arrived  at  by  Cook 


Wasps,  Bees,  and  Ants  ^yc 

is  that  the  morphological  character  of  the  gall  depends  upon  the  genus  of 
the  insect  producing  it  rather  than  upon  the  plant  on  which  it  is  produced; 
i.e.,  galls  produced  by  insects  of  a  particular  genus  show  great  similarity  of 
structure  even  though  on  plants  widely  separated;  while  galls  on  a  particular 
genus  of  plants  and  produced  by  insects  of  different  genera  show  great  differ- 
ences. The  formation  of  the  gall  is  probably  an  effort  on  the  part  of  the 
plant  to  protect  itself  from  an  injury  which  is  not  sufficient  to  cause  death. 

An  additional  interesting  feature  in  the  economy  of  Cynipid  hfe  is  the 
presence  in  the  galls  of  other  insects  besides  the  gall-makers.  These  others 
are  on  two  footings,  that  is,  some  are  guests  or  commensals,  and  some  are 
true  parasites,  either  on  the  gall-makers  or  on  the  guests!  Curiously,  among 
both  guests  and  parasites  are  members  of  the  same  family,  Cynipida\  to 
which  the  makers  and  rightful  owners  of  the  galls  belong.  Others  of  the 
parasites  may  belong  to  the  various  well-known  parasitic  hymenopterous 
families,  as  the  Ichneumonidae,  Chalcididae,  Braconidaj,  etc.,  while  others 
of  the  commensals  may  belong  to  entirely  distinct  orders,  as  the  Coleoptera, 
Lepidoptera,  etc.  Kieffer  (a  famous  French  student  of  galls  and  gall-flies) 
gives  the  following  amazingly  large  hst  of  commensals  and  parasites  bred 
from  a  common  root-gall  on  oak,  Biorhiza  pallida:  Commensals,  the  larvae 
of  five  species  of  moths,  of  one  fly,  of  one  beetle,  of  one  Neuropteron,  and  of 
two  Cynipids;  parasites,  a  total  of  41  species,  bred  mostly  from  the 
various  commensals. 

The  guest  gall-flies,  called  inquilines,  are  often  surprisingly  similar  to 
the  species  which  actually  produces  the  gall.  A  similar  likeness  between 
host  and  guest  exists  in  the  case  of  the  bumblebee  (Bombus)  and  its  guest 
Psithyrus  (closely  related  to  Bombus).  It  may  be  that  the  guest  species  is  a 
degenerate  loafing  scion  of  the  working  stock. 

The  group  of  gall-flies  and  their  allies  is  looked  on  as  a  superfamily,  the 
Cynipoidae,  in  the  latest  authoritative  classification  (Ashmead)  of  the  Hymen- 
optera,  and  divided  into  subfamilies,  the  Cynipidae  including  the  gall-makers, 
and  the  much  smafler  family,  Figitidas,  including  the  parasitic  species.  Only 
about  a  score  of  parasitic  Cynipoids  are  yet  known  in  this  country,  while 
over  200  gall-making  species  and  inquilines,  or  guest  species,  are  known. 

To  collect  gall-flies  the  galls  should  be  gathered  especially  in  the 
autumn,  for  with  the  end  of  the  growing  season  the  larvae  are  mostly  full- 
grown  and  ready  to  pupate.  They  should  be  separated  according  to  kind, 
those  of  each  kind  being  put  into  small  closed  bags  of  fine-meshed  bob! net 
or  tarlatan.  In  these  the  various  gall-flies,  inquilines,  commensals  of  other 
orders,  and  the  parasites  will  issue,  and  may  be  thus  identified  with  their 
proper  gall. 

In  the  account  of  the  Cynipidaj  reference  has  been  made  to  the  division 
into  gall-making  species  and  parasitic  species,   the  latter  constituting  but 


476 


Saw-flies,  Gall-flies,  Ichneumons, 


a  small  part  of  the  whole  family.  The  parasitic  habit,  only  slightly  indulged 
in  among  the  Cynipidae,  is,  however,  the  prevailing  one  of  a  majority  of  Hy- 
menopterous  insects.  Although  we  commonly  think  of  bees,  ants,  and  wasps 
as  the  typical  Hymenoptera  and  as  constituting  the  bulk  of  the  order,  it  is  a 
fact  that  in  point  of  numbers  they  are  far  outclassed  by  the  parasitic  forms 
whose  life  is,  like  that  of  the  social  Hymenoptera,  also  highly  speciaUzed, 


Fig.  668. — Caterpillar  of  a  moth  killed  by  Hymenopterous  parasites,  the  adult  parasites 
having  issued  from  the  many  small  circular  holes  in  the  body-wall.  (After  Jordan 
and   Kellogg;    twice    natural  size.) 

but  along  a  radically  different  line.  In  a  half-dozen  families,  including  the 
largest  in  all  the  order,  nearly  every  species  is  a  parasite  and  a  parasite  of 
other  insects.  Indeed  the  chief  agents  in  keeping  the  great  insect  host  so 
checked  that  plants  and  other  animals  have  some  food  and  room  on  the 
earth  are  insects  themselves.  With  all  the  artificial  remedies  man  has 
devised  and  now  uses  against  the  attacks  of  insect  pests,  the  all-important, 
constantly  effective  check  on  these  pests  is  their  parasitization  by  the  host 
of  species  of  the  Hymenopterous  families  of  Chalcididae,  Braconidae,  Proc- 
totrypidae,  Ichneumonidae,  etc. 

These   parasitic   Hymenoptera   are   only   rarely   collected   by   amateurs, 


Fig.  669. — Larva  of  a  sphinx-moth  with  cocoons  of  a  parasitic  ichneumon-fly. 

(Natural  size.) 

although  caterpillar-breeders  always  get  acquainted  with  some  of  them,  to 
their  dismay  and  disgust.     But  even  if  collected,  the  unsettled  state  of  their 


Wasps,  Bees,  and  Ants 


477 


classification,  together  with  their  (mostly)  small  size  and  the  slight  and 
hardly  recognizable  differences  on  which  their  scientific  distinction  rests, 
would  make  their  systematic  study  nearly  impossible  for  the  amateur.  On 
the  other  hand  the  interesting  character  and  the  biologic  and  economic 
importance  of  their  habits  of  life  make  it  desirable  to  know  as  much  as  may 
be  about  their  life-history.  I  shall,  therefore,  give  the  little  space  which  our 
book  can  afford  to  these  insects  almost  exclusively  to  a  consideration  of  the 
ecologic  aspects  of  their  study. 


Fig.  670. — Hairy  caterpillar   killed   by   parasitic   ichneumon-flies   which    have   left  the 
body  through  small  holes  in  the  skin.     (Natural  size.) 

The  superfamihes  and  families  meant  to  be  included  among  the  insects 
referred  to  when  the  general  term  "parasitic  Hymenoptera"  is  used  are 
(using  Ashmead's  classification)  the 
superfamily  Proctotrypoidea,  a  great 
group  of  mostly  minute  species,  many 
of  which  pass  all  their  immature  life 
within  the  eggs  of  other  insects;  the 
superfamily  Chalcidoidea,  an  even 
larger  group,  also  of  small  species, 
but  with  a  few  forms  which  are  gall- 
makers  and  not  parasites;  and  the 
superfamily  Ichneumonoidea,  including 
the  larger  parasitic  Hymenoptera. 
Each  of  these  superfamihes  includes  a 
number  of  families,  and  the  three 
together  comprise  an  enormous  host 
of  mostly  little-known  insect  species. 
At  the  present  time  much  diversity 
exists  in  the  arrangement  of  the  various 
parasitic  families  in  entomological 
manuals.  In  the  older  books  the  para- 
sitic habit  has  been  looked  to  as  in- 
dicating an  aflSnity  of  relationship 
among  them  all ;  in  more  recent  books 
and  papers  is  adopted  an  arrangement 
proposed  by  Ashmead  which  indicates  a  nearer  relationship  on  the  part  of 


Fig.  671. — Caterpillar  killed  by  Hymen- 
opterous  parasites  which  have  issued 
from  the  cocoons  attached  to  the  skin 
of  the  caterpillar;  upper  figure  one  of 
the  adult  parasites.  (After  Jordan  and 
Kellogg;  caterpillar  and  cocoons  natu- 
ral size;   adult  parasite  much  enlarged.) 


4/8  Saw-flies,  Gall-flies,  Ichneumons, 

the  Proctotrypoidea  to  the  digger-wasps  (Sphecoidea)  and  to  the  gall-flies 
(Cynipoidea)  than  to  the  other  parasitic  groups  (Chalcidoidea  and  Ichneu- 
monoidea).  This  latter  arrangement  is  based  on  structural  unlikeness  among 
the  parasitic  groups  to  which  Ashmead  gives  much  classificatory  importance. 
Parasitism  is  a  condition  widely  spread  in  the  animal  kingdom,  parasitic 
species  being  found  in  most  of  the  invertebrate  phyla.  The  importance  of 
these  parasites  in  causing  disease  and  death  and  their  peculiar  biological 
interest  have  led  to  much  special  study  of  them  and  of  the  particular  phe- 
nomena of  parasitic  life.  Parasites  may  be  external  or  internal  as  they  cling 
to  the  outer  surface  of  their  host  or  burrow  within  the.  body;  permanent  or 
temporary  as  they  live  their  whole  life  or  only  part  of  it  in  or  on  the  host; 
but  in  almost  all  cases  except  in  those  of  our  parasitic  Hymenoptera  the 
parasite  shows  a  more  or  less  marked  degeneration  or  simplification  by 
loss  of  parts  of  its  body  structure.  Lice  and  fleas  are  the  degenerate  wing- 
less descendants  of  winged  ancestors;  the  intestinal  worms  are  for  the  most 
part  without  sense-organs;  the  tumor-like  Sacculina,  parasite  of  crabs,  has 
a  body  made  up  of  feeding  and  reproductive  organs  and  little  else.  But 
the  parasitic  hymenoptera  show  little  or  nothing  of  this  insidious  degenera- 
tion due  to  the  adoption  of  a  parasitic  life.  The  reasons  for  this,  however, 
are  fairly  obvious  when  the  life-history  and  life-conditions  of  these  insects 
are  inspected. 

The  general  course  of  the  life  and  the  character  of  the  various  stages  of 
a  parasitic  hymenopteron  are  as  follows:    the  winged,  free-flying  female  (the 

males  are  winged  and  free-flying  also) 
searches,  often  widely,  for  its  special 
host  species  in  that  stage, egg  or  larval, 
on  or  in  which  its  eggs  are  to  be  laid. 
This  host  may  be  always  an  individ- 
ual of  a  particular  species  or  may  be 
one  of  any  of  several   usually  allied 
species.     The   hosts  represent   most 
of  the  larger  insect  orders,  although 
caterpillars  of  moths  and  butterflies 
Fig.  672. — A    common     parasite,    Merisiis   furnish  the   great   majority  of  hosts 
destructor,  itva^l^,  of  the  Hessian  fly   (After   ^^^  ^^^  parasitic  Hymenoptera.     On 
Lugger;    natural  size  mdicated  by  line.)  ^  r     ,        1      1 

the  surface  of   the   body,   or,  more 

rarely,  inserted  beneath  the  skin,  the  parasite  deposits  one  or  several  eggs. 
The  footless,  maggot-like  larvae  soon  hatch,  and  if  not  already  inside  the 
host's  body  very  soon  burrow  into  it.  Here  they  lie,  feeding  on  its  body, 
tissues,  growing  and  developing  until  ready  to  pupate.  They  may  now 
eat  their  way  out  of  the  enfeebled  and  probably  dying  host  to  pupate  in  little 
silken  cocoons  or  fluffy  silken  masses  on  or  off  its  body-surface,  or  may  pupate 


Wasps,  Bees,  and  Ants 


479 


within  the  body.  In  the  latter  case  the  issuing  winged  adults  have  to  bite 
their  way  out.  The  host  usually  dies  before  its  time  for  pupation  has  arrived, 
but  in  some  species  it  succeeds  in  pupating  beforehand.  The  parasitic 
Hymenopterous  larvie,  while  degenerate  in  the  same  way  as  the  footless, 


Fig.  673.  Fig.  674. 

Fig.   673. — A  chalcid  fly,  Pteroptrix  flavimedia.     (After  Howard;    much  enlarged.) 
Fig.  674. — A  chalcid  parasite,  Aspidiotiphagus  citrinus,  of  one  of  the  scale-insects  of 
the  orange.     (After  Howard;    much  enlarged.) 

eyeless,  antennaless  maggots  of  house-flies,  are  not  more  so.  Their  parasitic 
habit  has  led  to  no  such  extraordinary  structural  specialization  through 
degenerative  loss  or  reduction  of  parts  as  is  the  usual  condition  in  other 
parasites. 

While  Lepidopterous  larvae  undoubtedly  furnish  the  majority  of  hosts 
for  the  parasitic  Hymenoptera,  they  are  by  no  means  the  only  ones.  The 
eggs  and  pupa  of  Lepidoptera  as  well  as  the  larvae,  Diptera,  Coleoptera, 
Hymenoptera    in   both  egg  and  larval  stages,   some  Hemiptera,   especially 


Pig.  675. — Labeo  longitarsis,  a  parasite  which  lives  in  a  sac  in  the  abdomen  of  a  Fulgorid, 
Liburnia  lentulenta.     (After  Swazey;    five  times  natural  size.) 

scale-insects  (Coccidae)  and  plant-lice  (Aphididae),  the  eggs  of  locusts  and 
other  Orthoptera,  and  some  Neuroptera  in  egg  and  larval  stage,  may  be 
infested;  in  fact  the  kinds  of  insects  which  may  serve  as  hosts  for  the  para- 
sitic Hymenoptera  strongly  outnumber  the  kinds  that  do  not. 

While  as  a  general  rule  each  parasite  confines  its  attacks  to  a  single  host- 
species,  there  are  numerous  exceptions;  and  on  the  other  hand  the  host 
itself  may  be  attacked  by  more  than  one  parasitic  species;  most  of  our  familiar 
Lepidoptera    are    parasitized   by  several    different    parasitic  Hymenoptera. 


480 


Saw-flies,  Gall-flies,  Ichneumons, 


For  example,  the  American  tent-caterpillar  has  been  found  by  Fiske  (New 
Hampshire)  to  be  attacked  by  twelve  species. 

With  regard  to  the  number  of  parasitic  individuals  that  may  live  at  the 
expense  of  a   single  host  individual  no  generalization  can  be  made;    the 


Fig.  676. — Hymenopterous  parasites  of  a  social-wasp.  Fig.  i,  nest  of  Vespa  sp.,  portion 
of  two  envelopes  cut  away  (two-thirds  natural  size);  fig.  5,  an  adult  parasite, 
Sphecophagus  (?)  predator,  female;  fig.  6,  male  of  same  species;  fig.  10,  Melittobia 
sp.,  female.     (After  Zabriskie;    natural  size  indicated  by  lines.) 


number  varies,  Howard  says,  from  i  to  3000.  From  a  single  caterpillar 
of  the  cabbage-moth,  Plusia  brassica,  2500  individuals  of  the  parasite  Copi- 
dosoma  truncatellum  have  been  bred.  From  large  hosts  are  often  bred 
large  nimibers  of  parasites,  but  with  some  parasitic  species  only  one  or  a  few 
eggs  are  ever  laid  on  a  single  host,  whether  it  be  large  or  small.  Small  hosts 
cannot,  of  course,  provide  food  for  many  parasites  and  hence  the  number  in 


Wasps,  Bees,  and  Ants 


481 


their  case  is  always  limited.      Still,  from  a  single  scale-insect  hardly  more 
than  ^  inch  long  a  dozen  and  more  tiny  parasites  have  been  bred. 

A  question  of  interest  is  that  regarding  how  many  individuals  of  a  single 
host-species  may,  in  a  given  locality,  be  parasitized.  For  the  effectiveness 
of  any  parasite  in  keeping  an  injurious 
insect  pest  in  check  depends,  of  course, 
on  its  relative  prevalence.  Touching 
this  may  be  quoted  Fiske's  estimate 
that  less  than  20  per  cent  of  the  Ameri- 
can tent-caterpillars,  which  are  at- 
tacked by  a  total  of  twelve  species 
of  parasites,  are  destroyed  annually 
in  the  vicinity  of  Durham,  N.  H. 
On  the  other  hand  I  have  found 
a  constant  parasitization  of  about 
two-thirds  of  all  the  pupating  indi- 
viduals of  the  California  oak-worm 
moth  (Phryganidia  calijornica)  in 
years  of  its  abundance  in  the  vicin- 
ity of  Stanford  University,  and  this 
by  the  single  ichneumon-fly,  Pimpla 
hehrendsii. 

The  success  of  any  form  of  para- 
sitism in  any  one  locality  in    a  given 


Fig.  677. — Larvae  of  certain  curious  hymen- 
opterous  parasites;  at  left,  Platygaster 
instricator;  at  right,  P.  herricki,  which 
live  in  the  alimentary  canal  of  Cecidio- 
myid  flies,  ant,  antennae;  lb,  labrum; 
wj,  mandible;  //,  labium;  /,  4/3,  legs;  kr, 
clawed  processes;  /,  lobe-like  processes; 
hj,  posterior  processes.  (After  Kulagin; 
much  enlarged.) 

season  brings  up  also  the  interesting  matter  of  host  and  parasite  "  cycles." 

It  is  obvious  that  in  the  face  of  a  scarcity  of  host  individuals  the  dependent 

parasitic  species  are  bound  to  find  difficulty  in 

maintaining  themselves;   and  conversely,  that 

with  the  increase  of  the  host  in  numbers  "  good 

hunting"  arrives  for  the  parasites.     But  the 

good  times    bring    hard    ones  in  their  train; 

for    when  hosts  are   abundant   the  parasites 

increase  so  rapidly  in  numbers  (having  usually 

several  generations  to  the  host's  one)  as  soon 

to  overcome  and  sometimes  almost  extinguish 

in  any  given  locality  the  host-species,  which 

of  course,  means  starvation  for  the  parasite 

and  a  new  lease  of  life  for  the  host.     Thus  are 

brought  about   succeeding    "cycles"   of   host 

and  parasite  abundance  intimately  associated  with  each  other.     In  the  case 

of  the  California  oak-worm  moth  already  referred  to,  a  serious  pest  (when 

abundant)  of  the  beautiful  live  and  white  oaks  of  California,  the  cycles  are 


Fig.  678. — Pimpla  sp.,  an  ichneu- 
mon-fly.     (Twice  natural  size.) 


482 


Saw-flies,  Gall-flies,  Ichneumons, 


well  marked,  and  we  have  come  to  rely  on  the  effectiveness  of  the  parasite  spe- 
cies, Pitnpla  behrendsii,  in  overtaking  by  rapidly  succeeding  generations  the 
increasing  hosts  of  the  pest,  and  in  checking  it  before  the  actual  realization 
of  what  is  not  infrequently  threatened,  the  killing  of  all  the  live-oaks  in 
certain  regions  of  the  state. 

An  interesting  phenomenon  in  the  biology  of  these  parasites  is  that  of 
hyperparasitism.  It  frequently  happens  that  the  parasites  of  a  given  host 
are  themselves  parasitized  by  other  (usually  smaller)  parasitic  Hymenoptera, 
while  even   these   secondary  parasites  are  not   infrequently  parasitized  in 

their  turn  by  still  other  species.  Indeed  some 
cases  are  known  in  which  the  tertiary  parasites 
are  infested  by  a  fourth  or  quaternary  species. 
An  excellent  example  of  hyperparasitism  is  re- 
vealed by  Fiske's  careful  study,  already  referred 
to,  of  the  hymenopterous  parasites  of  the  Ameri- 
can tent-caterpillar.  Twelve  species  of  parasitic 
hymenoptera  infest  these  caterpillars;  of  these 
twelve,  six  are  themselves  attacked  by  parasites 

(secondary),  of  which  as  many  as  six  species  may 
Fig.    eyg.—Ophio,!       purga-    \  V'  .  .   ,1  • 

turn,   an  ichneumon-para-   attack  a  smgle  species  of  the  primary  parasites. 

site  of  army-womis.   (After    Among   these  secondary  parasites    are    not    only 
ugger,  na  ura  size.;  species   distinct   from  the  primary  parasites,  but 

some  of  the  primaries  parasitize  each  other  as  well  as  the  caterpillars.  Of 
the  secondary  parasites,  four  species  are  in  turn  parasitized  by  other  (ter- 
tiary) parasites,  of  which  three  species  have  been  noted,  one  occurring  also 
as  a  secondary  parasite;  and  finally,  one  of  these  tertiary  parasites  is 
infested  by  another  of  the  tertiary  group,  which  in  this  instance  becomes 
a  quaternary  parasite.     Thus  the  old  rhyme  of 


"Great  fleas  have  little  fleas 
Upon  their  backs  to  bite  'em, 
And  little  fleas  have  lesser  fleas, 
And  so  ad  infinitum," 


is  often  realized  in  the  biology  of  the  parasitic  hymenoptera. 

Most  interesting  questions  are  suggested  when  we  consider  the  unusual 
life-conditions  that  may,  and  often  do,  obtain  in  parasitism.  Lying  immersed 
in  the  blood-lymph  of  the  body-cavity  of  the  host,  how  does  the  parasitic 
larva  breathe,  excrete,  moult,  etc.  ?  The  process  of  feeding  consists  prob- 
ably for  the  most  part  simply  in  the  taking  up  of  the  food  from  the  host's 
blood,  in  many  cases  probably  as  much  through  the  skin,  by  osmosis,  as  through 
the  mouth  itself.     With  some  species,  however,  there  seems  to  be  a  definite 


Wasps,  Bees,  and  Ants  483 

attack  on  certain  of  the  solid  tissues,  as  muscles,  fat-body,  etc.  Such  attacks 
necessarily  avoid  the  vital  organs  or  the  host  would  be  killed  long  before 
the  parasitic  larva  is  ready  to  pupate.  With  regard  to  the  breathing  it  has 
been  variously  suggested  that  the  larva  applies  itself  to  air-tubes  (tracheae) 
in  the  host-body  in  such  a  way  as  to  effect  an  exchange  of  gases ;  that  it  needs 
no  more  oxygen  than  it  obtains  in  the  body  fluid  of  the  host;  that  its  rela- 
tion to  the  host  is  analogous  to  that  of  fa-tus  to  mother  among  viviparous 
animals.  Seurat's  observations  seem  to  indicate  (for  certain  species  at 
least)  that  soHd  food  as  well  as  blood-lymph  is  taken  in;  that  respiration 
is  effected  through  the  skin  by  osmosis,  that  excretion  from  the  intestine 
does  not  occur  until  after  the  pupal  cocoon  is  formed,  and  that  moulting 
actually  occurs. 

The  host  of  species  and  the  difficulties  attending  their  determination, 
even  (for  amateurs)  as  regards  their  family  classification,  let  alone  their 
generic  and  specific  identification,  have  led  me  to  avoid  any  reference  to  the 
systematic  study  of  these  parasites.  Certain  particular  species,  especially 
among  the  larger  forms,  are  of  course  more  or  less  re- 
cognizable and  familiar  to  observers.  Among  the  larger 
species,  most  of  which  belong  to  the  superfamily 
Ichneumonoidea,  those  of  the  genera  Pimpla  (Fig.  678) 
and  Ophion  (Fig.  679)  are  especially  famiUar.  P.  con- 
qidsitor  (Fig.  680)  is  the  commonest  parasite  of  the  tent- 
caterpillars  (Clisiocampa),  is  also  the  chief  one  of  the  de- 
structive cotton-worm,  Aletia  argillacea,  of  the  south  and 
has  been  bred  from  half  a  dozen  other  species  of  moths. 
It  lays  its  eggs  not  on  the  larvae  of  the  tent-caterpillar 
moth,  but  on  the  pupae  (and  perhaps  on  the  cater-  Fig.  680.  —  Pimpla 
pillars  after  spinning  and  just  before  pupating)  inside  esg^^in  Tocoorf ^  of 
the  silken  cocoon  (Fig.  680).  P.  inquisitor,  a  common  American tent-cater- 
parasite  of  the  tussock-caterpillars,  is  an  ichneumon-  piske -^bout  natural 
fly  whose  life-history  is  given  in  much  detail  by  Howard  size.) 
in  the  Insect  Book.  The  Ophions  are  light  brown  or 
golden  in  color,  with  abdomen  much  compressed  laterally.  A  common 
species  parasitizes  the  giant  larvae  of  the  polyphemus  moth;  but  huge  as 
this  caterpillar  is,  only  one  egg  is  laid  on  it  by  the  Ophion. 

The  wonderful  Thalessa,  with  its  flexible  ovipositor  six  inches  long,  with 
which  it  drills  a  hole  deep  into  a  tree-trunk  until  it  reaches  a  tunnel  of  the 
wood-boring  larva  of  Tremex,  has  already  been  referred  to  (see  p.  467). 
Comstock  describes  Thalessa  as  follows:  "Its  body  is  2 J  inches  long  and  it 
measures  nearly  10  inches  from  tip  of  antenna  to  tip  of  the  ovipositor. 
When  a  female  finds  a  tree  infested  by  the  Tremex  she  selects  a  place  which 
she  judges  is  opposite  a  Tremex-buriow,  and,  elevating  her  long  ovipositor 


484 


Saw-flies,  Gall-flies,  Ichneumons, 


in  a  loop  over  her  back,  with  its  tip  on  the  bark  of  the  tree,  she  makes  a  der- 
rick out  of  her  body,  and  proceeds  with  great  skill  and  precision  to  drill  a 
hole  into  the  tree.     When  the  Tremex-burrow  is  reached  she  deposits  an 

egg  in  it.  The  larva  that  hatches  from 
this  egg  creeps  along  this  burrow  until 
it  reaches  its  victim,  and  then  fastens  itself 
to  the  horntail  larva,  which  it  destroys 
by  sucking  its  blood.  The  larva  of  Tha- 
lessa  when  full-grown  changes  to  a  pupa 
within  the  burrow  of  its  host,  and  the 
adult  gnaws  a  hole  out  through  the  bark 
if  it  does  not  find  a  hole  already  made  by 
the  Tremex.  Sometimes  the  adult  Tha- 
lessa,  like  the  adult  Tremex,  gets  her 
ovipositor  wedged  in  the  wood  so  tightly 


Fig.  681. 


Fig.  682. 


Fig.  681. — Thalessa  sp.,  ichneumon -parasite  of  the  pigeon-tremex.     (After  Jordan  and 

Kellogg;   natural  size.) 
Fig.  682. — Thalessa  lunator  drilling  a  hole  in  a  tree-trunk,  in  order  to  deposit  its  egg  in 

burrow  of  the  pigeon-tremex.     (After  Comstock;    natural  size.) 


that  it  holds  her  a  prisoner  until  she  dies." 

Another  curious  large  parasitic  Hymenopteron  is  Pelecinus  polyturator 
(Figs.  683  and  684),  the  single  American  representative  of  the  family  Pele- 
cinidse,  of  whose  habits  little  is  known,  but  which  has  attracted  much  atten- 
tion because  of  the  strange  discrepancy  in  size  between  male  and  female. 
The  abdomen  of  the  female  is  slender  and  i\  inches  or  more  in  length,  while 


Wasps,  Bees,  and  Ants 


485 


that  of  the  male  is  not  more  than  {  inch.     The  males,  only  about  ^  inch 

long,  are  much  more  rarely  seen  than  the  females. 

Among  the  smaller  parasitic  Hymenoptera, 
the  Chalcidids,  Braconids,  and  Proctotrypids,  but 
few  complete  life-histories  are  known.  Many 
of  the  Proctotrypids,  an  enormous  family  in 
number  of  species,  live,  all  but  the  winged  adult 
stage  of  their  life,  in  the  eggs  of  other   insects. 


Fig.  683. 

Fig.  683. — Pelecinus  polyturator,   female.     (Natural  size.) 
Fig.  684. — Pelecinus  polyturator  (?),  male       (Three  and  one-half  times  natural  size.) 

a  half-dozen  individuals  perhaps  in  a  single  egg;    needless  to  say  they  are 
among  our  smallest  insects.    Some  are  wingless,  some  show  a  marvelous  hyper- 


FiG.  685. 


-Meteorus  hyphantrm,  parasite  of  the  green-fruit  worms,  Xylma  sp. 
(After  Slingerland;    much  enlarged.) 


metamorphosis  in  their  life-history,  and  all  present  extremely  interesting  prob- 
lems to  biological  students.  Howard  gives  in  his  Insect  Book  an  account 
of  the  Ufe-history,  as  worked  out  by  Schwarz,  of  a  chalcis-fly,  Euplectrus 


486 


Saw-flies,  Gall-flies,  Ichneumons, 


comstockii,  which  infests  various  caterpillars.  Its  larvae  are  external  para- 
sites clinging  to  the  skin  of  the  caterpillar.  The  chalcis-fiies  may  usually  be 
recognized  by  the  characteristic  branched  single  vein  of  the  fore  wings  (Fig. 

673)- 

The  economic  importance  of  the  hymenopterous  parasites  is  obvious; 

from    the   point  of  view  of  the  economic  entomologist  there  are  no  other 


Fig.  686. — Larva  of  Xylina  lacticinerea,  green-fruit  worm,  killed  by  the  parasitic  grub 
of  Mesochorus  agilis,  which  has  spun  its  cocoon  beneath  the  caterpillar,  fastening 
the  latter  to  the  leaf.     (After  Slingerland;    natural  size.) 


insects  outside  of  the  pests  of  such  interest  as  these  natural  pest-fighters. 
Attempts  have  been  made  to  make  allies  of  them  in  man's  warfare  against 
injurious  insects  by  artificially  disseminating  them,  even  to  the  extent  of 

colonizing  by  importation  from  foreign 
countries  various  new  species  in  partic- 
ularly pest-ridden  localities.  In  Cali- 
fornia a  constant  and  aggressive  war  has 
to  be  maintained  by  the  fruit-growers 
against  many  insect  pests,  and  particu- 
larly against  the  scale-insects.  In  this 
warfare  a  number  of  attempts  have  been 
made  to  introduce  from  other  continents 
parasitic  enemies  of  the  scales.  Unques- 
tionably considerable  success  has  attended 
some  of  these  importations,  although  as 
yet  no  other  such  signal  overcoming  of  an 
insect  pest  by  the  use  of  these  Hessians 
has  occurred  as  attended  the  importation 
from  Australia,  several  years  ago,  of  the  predaceous  ladybird-beetle  (Vedalia), 
enemv  of  the  once  dreaded  fluted  scale  (see  p.  189  for  account  of  this). 
Any  discussion  of  the  parasitic  families  of  Hymenoptera  would  be  incom- 


FiG.  687. — A  caterpillar  of  Xylina 
lacticinerea,  green-fruit  worm,  from 
which  the  parasitic  larva  of  Mcteoriis 
hyphantricE  has  just  emerged  and 
is  spinning  its  cocoon,  (.\fter  Slin- 
gerland;    natural  size.) 


Wasps,  Bees,  and  Ants 


487 


Fig.  688.— The  fig-insect, 
Blostophaga  grossorum, 
male.  (After  Howard; 
much  enlarged.) 


plete  if  there  were  omitted  all  reference  to  certain  species  of  Chalcidoidea 
which  are  exceptions  to  the  general  condition  of  parasitism  obtaining  in  the 
group.  A  number — very  small  in  proportion  to  the  total  number  of  species 
in  the  superfamily — of  chalcidid  species  feed  upon  plants,  producing  small 
galls  on  the  plants  attacked.  The  wheat-joint  worm, 
Isosoma  hordei,  whose  larvae  live  in  small  swellings 
— produced  by  their  presence — in  the  stems  of  wheat 
and  other  grains,  is  a  familiar  example  of  these  phy- 
tophagous Chalcidids.  The  most  interesting  species 
of  this  kind,  however,  is  the  "caprifying"  fig-wasp, 
Blastophaga  grossorum.  There  are  several  species 
of  chalcidid  fig-insects,  but  the  species  mentioned  is 
the  particular  one  on  which  depends  the  develop- 
ment of  the  Smyrna  fig — by  far  the  best  of  the 
food-figs.  The  male  Blastophagas  (Fig.  688)  are 
grotesque,  wingless,  nearly  eyeless  creatures  which 
never  leave  the  fig  in  which  they  are  bred,  but  the  fe- 
males (Fig.  689)  are  winged  and  fly  freely  about  among  the  trees.  A  fig  is  a 
hollow,  thick,  and  fleshy-walled  receptacle  in  which  are  situated,  thickly 
crowded  over  the  inner  surface,  the  minute  flowers.  The  only  entrance  into 
the  receptacle  (or  fig)  is  a  tiny  opening  at  the  blunt  free  end  of  the  young 
fig,  and   even   this  orifice  is  closely  guarded  by  scales  that  nearly  close  it. 

The  eggs  are  laid  by  the  females  at  the  base 
of  the  little  flowers  in  certain  figs.  The 
hatching  larvae  produce  little  galls  in  which 
they  lie,  feeding  and  developing.  They 
pupate  within  the  galls,  and  the  wingless 
males  when  they  issue  do  not  leave  the 
interior  of  the  fig,  but  crawl  about  over  the 
galls,  puncturing  those  in  which  females 
lie,  and  thrusting  the  tip  of  the  abdomen 
through  the  puncture  and  fertilizing  the 
females.  The  fertilized  winged  female 
gnaws  out  of  the  galls,  and  leaves  the 
fig  through  the  smaU  opening  at  the 
blunt  free  end.  She  flies  among  the  trees  seeking  young  figs,  into  which 
she  crawls,  and  where  she  lays  her  eggs  at  the  bases  of  as  many  flowers  as 
possible.  But  it  is  only  the  wild,  inedible,  or  "caprifigs"  that  serve  her 
purpose.  The  flowers  of  the  cultivated  Smyrna  seem  to  offer  no  suitable 
egg-laying  ground  and  in  them  no  eggs  are  laid.  But  as  the  female 
walks  anxiously  about  inside  the  fig,  seeking  for  a  suitable  place,  she  dusts 
all  the  female  flowers  with  pollen  brought  on  her  body  from  the  male  flowers 


Fig.  689. — The  fig-insect,  Blastophaga 
grossorum,  female.  (After  Howard; 
much  enlarged.) 


488 


Saw-flies,  Gall-flies,  Ichneumons, 


of  the  caprifig  from  which  she  came,  and  thus  fertilizes  them.  This  process 
is  called  caprification*  Without  it  no  Smyrna  fig  has  its  flowers  fertilized 
and  its  seeds  "set."  It  is  the  development  of  the  seeds  with  the  accom- 
panying swelling  of  the  fleshy  receptacle  and  the  storing  of  sugar  in  it  that 
makes  the  Smyrna  fig  so  pleasant  to  the  palate.  The  trees  may  grow  large 
and  bear  quantities  of  fruit,  but  if  the  figs  (really  the  fig-flowers)  are  not 


FlG.  690. — Figs  on  a  branch;  the  two  lower  ones  are  mammae,  winter  figs,  from  which 
Blastophaga  are  about  to  issue;  the  others  are  profichi,  spring  figs,  ready  to  receive  the 
Blastophaga.     (After  Howard;   natural  size.) 

caprified,  the  size,  sweetness,  and  nutty  flavor  of  the  perfect  fruit  are  lacking. 
To  insure  caprification,  branches  laden  with  caprifigs  containing  Blastopha- 
gas  just  about  to  issue  are  suspended  artificially  among  the  branches  of  the 

*  For  an  account  of  the  important  role  played  by  insects  in  the  fertilization  of  flowers 
see  Chapter  XVI. 


Wasps,  Bees,  and  Ants  489 

Smyrna  fig.  Of  course  the  female  Blastophaga  entering  a  Smyrna  fig  and 
dying  there  leaves  no  progeny,  for  she  lays  no  eggs.  It  is  therefore  necessary 
to  maintain  a  plantation  of  caprifigs  in  or  near  the  Smyrna  orchard.  These 
bear  three  crops  or  generations  of  figs:   one,  the  "profichi,"  ripening  in  the 


Fig.  691. — Figs  showing  effect  of  non-caprification  and  of  caprification.  a,  outside 
appearance  of  non-caprified  fig;  b,  outside  of  caprified  fig;  c,  interior  of  caprified 
fig;    d,   interior  of  non-caprified   fig.     (After  Howard;    natural   size.) 


spring;  another,  the  "mammoni,"  ripening  in  the  late  summer;  and  the  third, 
or  "mammae"  generation,  which  hangs  on  the  trees  through  the  winter.  By 
means  of  these  successive  generations  of  caprifigs  a  series  of  three  genera- 
tions (or  sometimes  four)  of  Blastophaga  appear  each  year. 

In  this  country  California  fruit-growers  have  long  grown  figs,  but  they 
were  of  a  quahty  very  inferior  to  the  well-known  Smyrna,  whose  home  is  in 
Asia  Minor.  But  the  persistent  efforts  of  an  orchard-owner  of  the  San  Joa- 
quin Valley,  Mr.  George  Roeding,  with  the  assistance  of  expert  entomolo- 
gists of  the  United  States  Division  of  Entomology,  have  resulted,  after  numer- 
ous unsuccessful  trials  extending  over  ten  years,  in  establishing  by  direct 
importation  from  Asia  Minor  the  Blastophaga  in  California,  and  the  pro- 
duction of  figs  of  the  same  quality  as  that  of  the  Asiatic  fruit.  From  capri- 
fig-trees  (grown  from  cuttings  originally  imported  from  Smyrna)  scattered 
through  a  sixty-acre  orchard  of  Smyrna  fig-trees  (also  obtained  from  imported 
cuttings  and  which  Mr.  Roeding  maintained  for  fourteen  years  without  any 
financial  return)  figs  containing  Blastophagas  ready  to  issue  are  taken  ofJ, 
strung  on  short  raffia  strings,  and  hung  on  the  branches  of  the  Smyrna  fig- 
trees  when  the  Smyrna  fruit  is  ready  for  fertilization.  In  1900  the  first  crop 
of  California  Smyrna  figs  was  obtained — sixty  tons,  all  from  this  orchard — 
and  it  is  now  practically  certain  that  the  colonization  of  the  tiny  chalcidid  fly, 
Blastophaga  grossonim,  in  CaUfornia  has  added  another  important  fruit 
to  the  list  of  horticultural  products  of  that  State. 


490  Saw-flies,  Gall-flies,  Ichneumons, 


WASPS. 

We  have  now  to  take  up  the  more  familiar  groups  of  wasps,  bees,  and 
ants,  in  all  of  which  the  females  (and  the  sterile  workers  in  those  species  in 
which  such  kind  or  caste .  of  individuals  exists)  have  a  sting.  The  sting 
(see  description  of  that  of  the  honey-bee  on  p.  460)  is  really  the  same  struc- 
ture as  the  slender,  pointed,  often  long  ovipositor  of  the  parasitic  Hymen- 
optera;  but  whereas  in  the  saw-flies,  homtails,  and  true  Parasita  this  instru- 
ment is  used  for  piercing  or  drilling  a  hole  and  placing  the  egg  in  it  or  on 
the  body  of  the  host — the  egg  passing  along  the  whole  length  of  the  ovipositor 
and  issuing  from  its  tip — in  the  so-called  aculeate  Hymenoptera,  that  is,  the 
stingers,  the  egg  issues  from  the  body  at  the  base  of  the  instrument  which  is 
itself  used  as  a  weapon  of  offence  and  defence.  In  most  of  the  ants  of  our 
country  the  sting  is  rudimentary  and  functionless,  but  traces  of  it  and  its 
poison  can  be  found. 

The  Hymenopterous  insects  referred  to  by  the  generic  term  wasps  are 
many  and  various,  and  their  multiphcity  and  variety  have  led  to  the  formula- 
tion of  many  contradictory  schemes  of  classification  for  them.  That  adopted 
by  Comstock  in  his  Manual  groups  them  in  two  superf amilies :  one,  the  Sphe- 
cina,  or  digger-wasps,  including  fourteen  famihes;  the  other,  the  Vespina,  or 
so-called  true  wasps,  including  but  three.  The  Vespina  include  the  social 
forms,  as  the  yellow-jackets  and  the  hornets,  composing  the  family  Vespidae, 
one  family  of  solitary  parasitic  wasps,  the  Masaridae,  and  one  other  family  of 
solitary  mason,  carpenter,  leaf-cutting,  mining,  and  digging  wasps,  the 
Eumenidae.  The  Sphecina  include  wasps  all  sohtary  (not  social),  but  some 
of  them  parasitic,  some  inquiline,  some  earth-diggers,  and  some  carpenters 
and  wood  miners.  The  structural  character  separating  these  two  super- 
families  is  the  longitudinal  folding  or  plaiting  of  the  wings  in  the  Vespina, 
a  condition  not  present  in  the  Sphecina.  Some  systematists  refuse  to  recog- 
nize so  many  distinct  families  while  others  would  perhaps  subdivide  them 
into  a  still  larger  number.  The  latest  classification,  that  of  Ashmead,  recog- 
nizes two  superfamilies,  the  Sphecoidea,  or  insect-catching  wasps,  including 
twelve  families  whose  species  are  all  solitary,  none  parasitic,  and  all  diggers 
or  miners,  and  the  Vespoidea,  including  sixteen  families  of  social,  parasitic, 
guest,  and  mason  wasps,  together  with  a  few  diggers.  The  structural  char- 
acter separating  these  two  great  groups  of  wasps  is  the  extension  of  the  pro- 
notum  back  to  the  tegulag  or  shoulder-tippets  (or  the  absence  of  the  latter)  in 
the  Vespoidea,  and  the  failure  of  the  pronotum  to  extend  back  as  far  as  the 
tegulae  in  the  Sphecoidea.  All  the  bees  agree  with  the  Sphecoidea  in  this 
character,  so  that  Ashmead  thinks  the  Sphecoidea  more  nearly  related  to 
the  Apoidea  or  bees  than  the  Vespoidea  are,  despite  the  fact  that  all  the 


Wasps,  Bees,  and  Ants  491 

wasps  that  live  a  communal  life,  like  that  of  the  bumble-  and  honey-bees, 
belong  to  the  Vespoidea.  The  Sphecoidea  may  be  distinguished  from  the 
bees  by  their  slender  undilated  tarsi,  as  contrasted  with  the  swollen,  pollen- 
carrying  tarsi  of  the  bees. 

The  eggs  of  wasps  are  usually  deposited  in  a  nest  (burrow  in  soil,  tunnel 
in  wood,  receptacle  built  of  clay,  cells  made  of  wasp-paper,  etc.)  in  which 
food,  consisting  of  killed  or  paralyzed  insects,  is  stored  for  the  use  of  the 
larva,  or    to  which,  after    the   larva's        ^_    ^    ^c~. 
birth,  insect  food  is  brought  by  the       ~^^^^^^i=i^=:. 
mother   or   by  sterile    workers.      The        "^^^^^^^^^^^ 
parasitic  wasps   deposit   their  eggs  on  ^^^^^^^S^=s. 

the   paralyzed   body   of    some   insect,  -^^^^^^^^^g^ 

while   the   guest  wasps  lay  their  eggs  ^^t:^^^^^^-""^  — '- - 

in   the   nests  of  other  wasps  or  bees,  ^-~  ~^^Mp-^^-^^ 

where  the  hatching  larva  can  feed  on  ^^^^H^^H^^^ 

the  food  stored  up  by  the  host  for  its  '^^^^^HU^^ 

own   young.      The    larvae   are   white,  "^^^^^gHMr  s=^ 

footless,  soft-bodied  grubs,  which   lie  ^^;-ssg^ssp^S. 

in  their  cells  feeding  on  the  food  stored  Fig.  6q2. — Nest-burrow  of  Oxybelus 
up    or   brought  them  and    pupating  in         quadri-notatus.     (After   Peckham;    one- 

the  same  cell.     The  adults  on  issuing 

from  the  pupal  cuticle  gnaw  their  way  out  of  the  cell  by  means  of  their 

strong  jaws.     With  the  social  wasps  all   the  eggs  are   laid  by  a  queen  or 

fertile   female  in  each   community;   with  the   solitary  ones  each  female  lays 

eggs. 

The  general  external  structural  characters  of  wasps  are  familiar:  the 
elongate  but  compact  and  trim  body  with  usually  smooth,  shining  surface, 
variously  colored  and  patterned,  steely  blue,  jet  black,  yellow,  and  rusty 
reddish  being  the  commoner  colors  and  the  pattern  usually  consisting  of 
narrow  or  broad  transverse  bands  or  rings.  All  have  four  clear  membra- 
nous wings  (excepting  the  female  Mutillidae),  and  all  the  females  and 
workers  have  strong  stings.  The  mouth-parts  consist  of  strong  toothed 
jaws,  of  jaw-like  maxillae  and  lobed  under  lip,  the  last  two  usually  closely 
joined  by  membranes  and  specially  fitted  for  lapping  up  sweetish  liquids 
or  soft  viscous  or  solid  substances.  The  killing  or  paralyzing  of  the  prey 
(food  for  the  young)  is  accomplished  by  the  sting,  while  the  digging  and 
mining  and  the  transporting  of  materials  for  the  nest  are  done  by  the  strong 
mandibles.  The  antennae  are  rather  long  and  slender,  the  compound  eyes 
large  and  many-faceted. 

The  digger-wasps  differ  from  the  social  kinds,  such  as  the  yellow-jackets 
and  hornets,  by  not  living  together  in  communities,  composed  of  a  queen, 
males,  and  sterile  workers,  but  by  living  sohtarily.      There  are  no  sterile 


492 


Saw-flies,  Gall-flies,  Ichneumons, 


worker  digger-wasps,  but  each  female  makes  a  separate  nest  and  provisions 
it  by  her  own  labor.  The  stored  food  consists  of  paralyzed  or,  more  rarely, 
killed  insects  or  spiders.  "The  nests  may  be  of  mud,  and  attached,  for 
shelter,  under  leaves,  rocks,  or  eaves  of  buildings,  or  may  be  burrows  hol- 
lowed out  in  the  ground,  in  trees,  or  in  the  stems  of  plants.  The  adult  wasp 
lives  upon  fruit  or  nectar,  but  the  young  grub  or  larva  must  have  animal 
food,  and  here  the  parent  wasp  shows  a  rigid  conservatism,  each  species 
providing  the  sort  of  food  that  has  been  approved  by  its  family  for  genera- 
tions, one  taking  flies,  another  bugs,  and  another  beetles,  caterpillars,  grass- 
hoppers, crickets,  locusts,  spiders,  cockroaches,  aphids,  or  other  creatures, 
as  the  case  may  be. 

"The  solitary  wasps  mate  shortly  after  leaving  the  nest,  in  the  sprmg 
or  summer.     The  males  are  irresponsible  creatures,  aiding  little,  if  at  all, 


Fig.  693. — A  solitary  wasp,  Sphex  occitanica,  dragging  a  large  wingless  locustid 
(Ephippiger)   to  nest.     (After  Fabre;    natural   size.) 

in  the  care  of  the  family.  When  the  egg-laying  time  arrives  the  female 
secures  her  prey,  which  she  either  kills  or  paralyzes,  places  it  in  the  nest, 
lays  the  egg  upon  it,  and  then,  in  most  cases,  closes  the  hole,  and  takes  no 
further  interest  in  it,  going  on  to  make  new  nests  from  day  to  day.  In  some 
genera  the  female  maintains  a  longer  connection  with  her  offspring,  not 
bringing  all  the  provisions  at  once,  but  returning  to  feed  the  larva  as  it  grows, 
and  only  leaving  the  nest  permanently  when  the  grub  has  spun  its  cocoon 
and  becomes  a  pupa. 

"The  egg  develops  in  from  one  to  three  days  into  a  footless  maggot-like 
creature,  which  feeds  upon  the  store  provided  for  it,  increasing  rapidly  in 
size,  and  entering  the  pupal  stage  in  from  three  days  to  two  weeks.  In  the 
cocoon  it  passes  through  its  final  metamorphosis,  emerging  as  a  perfect 
insect  perhaps  in  two  or  three  weeks,  or,  in  many  cases,  after  the  winter 
months  have  passed  and  summer  has  come  again.      Probably  no  sohtary 


Wasps,  Bees,  and  Ants 


493 


wasp  lives  through  the  winter,  those  that  come  out  in  the  spring  or  summer 
perishing  in  the  autumn." 

The  nest-making  habits  of  any  solitary  wasp,  when  carefully  observed, 
will  prove  to  be  of  absorbing  interest.     On  the  broad  salt  marshes  of  the 


Fig.  694. — Nesting-grounds  of  the   solitary  wasp,  Ammophila  sp.,  in  the  salt  marshes 

of  San  Francisco  Bay. 

western  shore  of  San  Francisco  Bay  near  Stanford  University  I  have  often 
watched  an  interesting  species  of  wasp  at  work.  This  is  one  of  the  genus 
Ammophila,  the  thread-waisted  sand-diggers.  The  marshes  are  nearly 
covered  with  a  dense  growth  of  a  low  fleshy-leaved  plant,  the  samphire  or 
pickle-weed  (Salicornia),  but  here  and  there  are  small,  perfectly  bare,  level, 
sandy  places,  which  shine  white  and  sparkling  in  the  sun  because  of  a  thin 
incrustation  of  salt.     In  September  these  bare  places  are  taken  possession 


Fig.  695. — Ammophila  putting  inchworm  into  nest -burrow.     (From  life;    natural  size.) 

of  by  many  female  Ammophilas,  which  make  short  vertical  nest-burrows  all 
over  the  ground.  An  Ammophila  having  chosen  a  site  for  its  nest  bites 
out  a  small  circular  piece  of  the  salty  crust,  and  with  its  strong  jaws  digs  out 
bit  by  bit  a  Httle  well.  Each  pellet  dug  out  is  carried  away  by  the  wasp, 
flying  a  foot  or  two  from  the  mouth  of  the  tunnel,  and  dropped.     To  emerge 


494 


Saw-flies,  Gall-flies,  Ichneumons, 


from  the  hole  the  wasp  always  backs  upward  out  of  it  and  while  digging 
keeps  up  a  low  humming  sound.  After  the  tunnel  is  dug  about  three  inches 
deep  she  covers  up  the  mouth  with  a  bit  of  salt  crust  or  little  pebbles,  and 
flies  away.  Some  minutes  later  she  comes  back  carrying  a  limp  inchworm 
about  an  inch  long,  which  she  drags  down  into  the  nest.  Away  she  goes 
again  and  soon  returns  with  another  inchworm;  repeating  the  process  until 
from  five  to  ten  caterpillars  have  been  stored  in  the  tunnel.  All  these  are 
alive,  but  each  has  been  stung  in  one  of  its  nerve-centers  (gangha)  so  that 
it  is  paralyzed.     Finally,  down  she  goes  and  lays  a  single  egg,  attaching 


Fig.  696.  Fig.  697. 

Fig.  696. — Nest-burrow  of  Ammophila,  with  food  for  the  young;    paralyzed  inchworms 

in  bottom  and  burrow  nearly  filled.     (Natural  size.) 
Fig.  697  — Ammophila  bringing  covering  bit  of  salt  incrustation  to  put  over  the  stored 

and  filled  nest-burrow.     (From  life;   natural  size.) 


it  to  one  of  the  paralyzed  caterpillars.  She  then  fills  the  tunnel  with  pellets 
of  earth,  carefully  chewing  up  the  larger  pieces  so  as  to  make  a  close,  well- 
packed  filling.  Lastly,  she  carefully  smooths  off  the  surface  and  puts  a 
small  flat  piece  of  salt  crust  on  top,  so  that  the  site  of  the  tunnel  shall  be  as 
nearly  indistinguishable  as  possible. 

Ammophilas  are  common  all  over  the  country,  and  the  nest-building 
of  various  species  has  been  watched  by  other  observers.  The  use  by  an 
individual  Ammophila  of  a  small  pebble,  held  in  the  jaws,  as  a  tool  to  pound 
down  and  smooth  off  the  earth  has  been  twice  recorded,  once  in  Wisconsin 
and  once  in  Kansas.  These  are  perhaps  our  only  records  of  the  use  of  a 
tool  by  an  insect. 

The  habits  of  the  Ammophila  described  above  are  typical  of  the  interest- 
ing life-history  which,  varying  indeed  in  many  details,  is  common  to  nearly  all 
of  the  solitary  wasps,  whether  belonging  to  the  Sphecoidea  or  Vespoidea. 


Wasps,  Bees,  and  Ants 


495 


Exceptions  are  those  species  which  Hve  as  guests  of  other  wasps,  or  as  para- 
sites on  other  insects. 

The  habit  common  to  almost  all  of  the  solitary  wasps  of  so  stinging  the 
prey,  caterpillars,  spiders,  beetles,  flies,  bugs,  or  whatever  other  insects 
are  used  to  provision  the  nests,  as  not  to  kill  but  only  to  paralyze  it,  is  perhaps 
the  most  amazing  part  of  all  the  interesting  behavior  of  all  these  wasps. 
The  advantage  is  obvious:  killed,  the  prey  would  quickly  decompose,  and 
the  hatching  carnivorous  wasp  larva  would  have  only  a  mass  of,  to  it,  inedible, 
decaying  flesh  instead  of  the  fresh  live  animal  substance  it  demands.  But 
if  stored  unhurt,  the  prey  would,  if  a  cricket  or  spider  or  similarly  active 
animal,  quickly  escape  from  the  burrow,  or  if  a  caterpillar  or  weak  bug,  at 
least  succeed,  albeit  unwittingly,  in  crushing  the  tender  wasp  egg  by  wrig- 
ghng  about  in  the  underground  prison-cell.  More  than  that,  unhurt,  some 
insects  could  not  live  without  food  the  many  days  that  are  necessary  for 
the  development  of  the  wasp  larva,  especially  in  the  face  of  the  frantic  and 
exhausting  efforts  they  would  be  impelled  to  in  their  attempts  to  escape. 
But  paralyzed,  there  is  no  exertion,  metabolism  is  slight,  and  hfe  without 
food  is  capable  of  being  prolonged  many  days.  The  paralysis  is  due  to 
the  stinging  by  the  wasp  of   one   or  more   of  the  ganglia  (nerve-centers) 


Fig.  698. — Cerceris  tnherculata,  dragging  weevil  {Cleonus  sp.)  to  nest. 
(After  Fabre;  natural  size.) 

of  the  ventral  nerve-cord.     With  a  wasp  species  (Sphex  flavipennis)  observed 
by  Fabre,*  which  provisions  its  nest  with  crickets,  each  cricket  was  stung 


*  Fabre,  J.  H.,  Insect  Life,  1901. 


49  6  Saw-flies,  Gall-flies,  Ichneumons, 

three  times,  once  in  each  thoracic  ganglion  which  resulted  in  immediate 
complete  paralysis.  Cerceris  tuberculata  hunts  weevils  (Cleonus)  (Fig.  698) 
and  stings  them  exactly  in  the  large  central  ganglion  formed  by  the  fusion 
of  the  three  thoracic  ganglia,  paralyzing  them  immediately.  Insects  thus 
paralyzed  will  keep  alive,  flexible,  and  fresh,  but  immovable,  as  Fabre  has 
observed,  for  six  weeks,  a  much  longer  time  than  is  necessary  for  the  develop- 
ment of  any  of  the  wasp  larvae.  The  amazing  expertness  and  accuracy 
displayed  in  plunging  the  sting  into  exactly  those  spots  where  injury  will 
give  rise  to  exactly  that  physiological  phenomenon  in  the  prey  that  will  make 
it  available  for  the  special  conditions  attending  the  wasp  larva's  sustenance — 
this  adroitness  and  this  seeming  knowledge  of  the  structure  and  the 
physiology  of  the  prey  have  led  some  entomologists  to  credit  the  solitary 
wasp  with  anthropomorphic  quahties  that  are  quite  unwarranted.  The 
whole  behavior  is  probably  explicable  as  a  complex  and  advantageous  reflex 
or  instinct,  developed  by  selection. 

Similarly  the  whole  course  of  the  nest-building  and  provisioning  is  an 
elaborate  performance  wholly  for  the  sake  of  the  young  which  the  mother 
will  likely  never  see ;  and  these  young  in  turn  will  if  females  do  the  same  thing, 
perfectly  and  in  essentially  if  not  exactly  the  same  manner  without  ever 
previously  seeing  such  remarkable  processes  performed.  All  these  com- 
plex and  altruistic  habits  have  naturally  led  to  much  speculation  concern- 
ing their  origin  and  their  relation  to  psychical  conditions.  Whether  a  con- 
sciousness of  what  is  being  done  and  an  intelligence  is  brought  to  bear  upon 
its  doing;  whether  we  may  attribute  to  the  wasp  a  psychical  state,  with  its 
attributes  of  cognizance,  reason,  and  emotion — these  are  questions  which 
are  debated  warmly.  The  consensus  of  opinion,  however,  is  distinctly 
adverse  to  the  reading  into  the  behavior  of  Ammophila  or  any  of  its  allies 
anthropormorphic  attributes  of  reason,  consciousness,  and  emotion. 

The  fixity  and  inevitableness  which  is,  despite  the  slight  variations  of 
practice  noted  by  the  Peckhams,*  pre-eminently  characteristic  of  the  behavior 
of  the  wasps,  and  the  fact  that  each  female  is  ah  ovo  adequate  to  carry  through 
the  complex  train  of  actions  without  teaching,  experience,  or  opportunity 
for  imitation,  practically  prove  all  this  seeming  marvel  of  reasoned  care  for 
the  future  young  to  be  an  inherited  instinct  incapable  of  essential  modification 
except  by  the  slow  process  of  selection  through  successive  generations. 

Nevertheless,  as  Sharp  well  says,  the  great  variety  in  the  habits  of  the 
species,  the  extreme  industry,  skill,  and  self-denial  they  display  in  carrying 
out  their  voluntary  labors,  render  the  solitary  wasps  one  of  the  most  instruc- 
tive groups  of  the  animal  kingdom     "The  individuals  of  one  generation 

*  Peckham,  Geo.  W.  and  Eliz  G.,  On  the  Instincts  and  Habits  of  the  SoUtary  Wasps, 
Bull.  2,  Wis.  Geol.  and  Nat.  Hist.  Survey,    1898. 


Wasps,  Bees,  and  Ants 


497 


only  in  rare  cases  see  even  the  commencement  <  f  the  hfe  of  the  next;  the 
progeny  for  the  benefit  of  which  they  labor  with  unsurpassable  skill  and 
industry  being  unknown  to  them.  Were  such  a  solicitude  displayed  by 
ourselves  we  should  connect  it  with  a  high  sense  of  duty,  and  poets  and 
moralists  would  vie  in  its  laudation.  But  having  dubbed  ourselves  the 
higher  animals,  we  ascribe  the  eagerness  of  the  solitary  wasp  to  an  impulse 
or  instinct,  and  we  exterminate  their  numerous  species  from  the  face  of  the 
earth  for  ever,  without  even  seeking  to  make  a  prior  acquaintance  with  them. 
Meanwhile  our  economists  and  moralists  devote  their  volumes  to  admira- 
tion of  the  progress  of  the  civihzation  that  effects  this  destruction  and  toler- 
ates this  negligence." 

Sharp  divides  the  solitary  wasps,  according  to  their  habits,  roughly  into 
four  groups:  (i)  those  that  form  no  special  receptacles  (nests)  for  their  young, 
but  are  either  of  parasitic  or  subparasitic  habits  or  take  advantage  of  the 
abodes  of  other  insects,  holes,  etc.;  (2)  constructors  of  cells  of  clay  formed 
into  pottery  by  the  saliva  of  the  insect, 
and  by  drying;  (3)  excavators  of  burrows 
in  the  ground;  (4)  makers  of  tunnels  in 
wood  or  stems  of  plants.  Several  species 
make  use  of  both  of  the  last  two  methods. 

Some  of  the  parasitic  wasps  dig  into 
the  ground  until  they  find  some  underground 
insect,  usually  a  larva,  for  example  a  beetle- 
grub,  which  they  sting  (paralyze)  and  on 
which  they  then  deposit  an  egg.  There 
is  no  attempt  to  make  a  nest  or  to  remove 
the  prey  from  its  position  as  found.  The 
hatching  wasp  larva  feeds  on  the  grub  but 
in  such  a  way  as  not  to  kill  it  before  its 
own  development  is  complete.  A  common 
parasitic  wasp  of  this  habit  is  Tiphia  inornaia, 
f  inch  long,  shining  black,  which  paralyzes 
white  grubs,  the  larvas  of  June-beetles. 
Other  allied  species,  some  yellow  and  black 
and  much  larger,  prey  on  other  larvae  of 
Scarabaeid  beetles      From  the  nests  of  other 

wasps,  and  of  both  solitary  and  communal  bees,  have  been  bred  several 
kinds  of  solitary  wasps  which  live  either  parasitically  or  as  guests  (inqui- 
lines)  in  these  nests.  If  guests,  their  larvae  feed  on  the  stored  food  of  the 
host;  if  parasites,  they  feed  on  the  actual  larval  or  adult  bodies  of  their 
hosts  themselves.  Interesting  wasps  living  habitually  in  nests  of  other 
wasps  or  bees   are   the   Mutillidae,  popularly   known   as   velvet-ants,   cow- 


Fig.  699. — A  cow-killer,  or  wingless 
wasp,  Spharophthalma  similima, 
female.  (After  Lugger;  natural 
size  indicated  by  line.) 


498  Saw-flies,  Gall-flies,  Ichneumons, 

ants,  or  cow-killers.  The  females  (Figs.  699  and  700)  are  wingless  and 
rather  like  ants  in  appearance,  although  readily  distinguishable  from  them 
by  their  covering  of  white,  red,  black,  or  golden  hair  and  of  course  by  the 
absence  of  the  scale-like  expansion  of  the  basal  abdominal  segments  char- 
acteristic of  the  true  ants.  The  males  are  winged  and  much  less  frequently 
collected  or  seen.  It  is  believed  that  all  Mutillids 
live  as  guests  or  parasites  in  the  nests  of  other  wasps 
or  bees.  They  are  strong  stingers  and  swift  runners. 
Nearly  two  hundred  species  have  been  found  in  the 
United  States,  the  center  of  abundance  being  in  the 
southwest.  They  are  common  in  California.  Sphce- 
rophthalma  caUjornica  (PI.  XII,  Fig.  i)  is  \  inch  long, 
with  brick-red  hair,  black  on  bases  of  abdomen  and 
thorax;    6'.   pacifica  is  similarly  colored  but    much 

Fig.    700. — Sphcerophthal-    ,  t-ii  o  i         ^     ■      t.     ^  i. 

ma  pacifica  (One  and  larger,  f  mch  long;  5.  aureola,^  i  mch  long,  has 
one-half  times  natural  head,  most  of  thorax,  and  posterior  half  of  abdomen 
^^^^■)  with  yellow  hair,  elsewhere  black. 

The  brilHant  metallic -green  little  bee-Hke  cuckoo-flies  (Chrysididae) 
are  not  unfamiliar  to  collectors,  and  belong,  because  of  their  habits,  in  the 
group  of  parasitic  wasps.  "Although  these  insects  are  handsome,"  says 
Comstock,  "they  have  very  ugly  morals,  resembling  those  of  the  bird  v/hose 
name  has  been  applied  to  them.  A  cuckoo-fly  seeks  until  it  finds  one  of 
the  digger-wasps,  or  a  solitary  true  wasp,  or  a  solitary  bee,  building  a  nest, 
and  when  the  owner  of  the  nest  is  off  collecting  provisions  steals  in  and  lays 
its  egg,  which  the  unconscious  owner  walls  in  with  her  own  egg.  Some- 
times the  cuckoo-fly  larva  eats  the  rightful  occupant  of  the  nest,  and  some- 
times starves  it  by  eating  up  the  food  provided  for  it.  The  bees  and  wasps 
know  this  foe  very  well,  and  tender  it  so  warm  a  reception  that  the  brilliant- 
coated  little  rascal  has  reason  enough  to  double  itself  up  so  that  the  righteous 
sting  of  its  assailant  can  find  no  hole  in  its  armor.  There  is  one  instance  on 
record  where  an  outraged  wasp,  unable  to  sting  one  of  the  cuckoo-flies  to 
death,  gnawed  off  her  wings  and  pitched  her  out  on  the  ground.  But  the 
undaunted  invader  waited  until  the  wasp  departed  for  provisions,  and  then 
crawled  up  the  post  and  laid  her  egg  in  the  nest  before  she  died." 

Of  mason-  or  potter-wasps,  that  is,  solitary  wasps  that  make  a  nest  of 
clay  or  mud  worked  up  with  saHva,  there  are  numerous  species  belonging 
to  several  different  families.  The  daintiest  mud-nests  are  the  little  vases 
of  Eumenes  (Fig.  701),  which  are  said  to  have  served  as  models  for  early 
Indian  pottery.  Eumenes  is  a  neat  little  black-and-yellow  wasp  with  the 
abdomen  shaped  like  an  old-fashioned  tear-drop  earring.  It  belongs  to  the 
family  Eumenidae,  which  is  the  only  family  of  solitary  wasps  (besides  the 
rarely  seen  parasitic  Masaridae)  which  fold  their  front  wings  longitudinally 


Wasps,  Bees,  and  Ants  499 

as  the  social  wasps  (yellow-jackets  and  hornets)  do.  In  this  family  are 
found  diggers,  and  miners  in  the  earth,  carpenters  making  their  nests  in 
twigs  or  boards,  as  well  as  masons  or  clay-handlers.  The  species  of  the 
genus  Odynerus  are  numerous;,  in  appearance  they  resemble  the  yellow- 
jackets,  but  are  smaller  and  more  slender.  They  are  given  to  taking  advan- 
tage of  any  deserted  nest  of  another  wasp,  or  of  some  already  existing  hole 
or  tunnel,  to  save  themselves  the  trouble  of  mining  or  moulding  a  nest  of  their 
own.  Riley  found  an  Odynerus  cell  in  the  tunnel  through  a  spool,  and  Ash- 
mead  found  one  in  the  keyhole  of  a  door-lock.     The  familiar,  long,  thread- 


FiG.  701.  Fig.  702. 

Fig.  701. — A  vase  mud-nest  of  Eumenes  sp.     (Natural  size.) 
Fig.  702. — Nest  of  a  mud-dauber  wasp.     (Natural  size.) 

waisted,  nervous,  black-and-yellow  or  steel-blue  mud-daubers  that  build 
several  tubular  cells  an  inch  or  more  long  side  by  side  of  mud,  plastered  to 
the  under  side  of  a  porch  roof,  on  ceilings,  under  eaves,  or  under  flat  stones, 
belong  to  the  genus  Pelopoeus  (PI.  XII,  Fig.  15)  of  the  large  family  Sphe- 
cidas.  These  cells  are  provisioned  with  paralyzed  or  dead  spiders.  Another 
smaller  kind  of  mud-dauber  is  Agenius,  a  genus  of  the  Pompilidiae.  The 
tiny  mud-cells  of  these  wasps,  built  in  crevices  or  on  stones,  are  also  pro- 
visioned with  little  spiders,  often  with  their  legs  torn  off.  Originally  the 
mud-daubers  built  their  nests  in  hollow  trees  or  under  overhanging  rocks,  as 
they  do  yet  sometimes;  but  they  mostly  nowadays  take  advantage  of  the  safe 
and  convenient  places  man  arranges  for  them. 

Of  Sharp's  fourth  group,  the  true  diggers  or  miners  in  the  ground,  I 
have  already  described  a  typical  species  in  the  Amrnophila  of  the  San  Fran- 
cisco Bay  salt  marshes.  There  are  many  species  of  this  genus,  and  they 
are  found  all  over  the  country.     The  great  golden  digger,  Sphex  ichneu- 


500 


Saw-flies,  Gall-flies,  Ichneumons, 


monea  (PI.  XII,  Fig.  14),  a  brilliant  and  powerful  Sphecid,  is  a  common 
and  widely  distributed  species,  which  makes  a  burrow  from  4  to  8  inches 
deep,  provisioning  it  with  green  grasshoppers.  The  Peckhams  have  described 
in  detail  in  their  fascinating  book,  "The  Solitary  Wasps,"  the  Ufe  and  habits 

of  two  species  of  Astata,  wasps 
of  the  family  Larridae,  which 
make  nests  with  funnel-like  open- 
ings (Fig.  703)  in  sandy  soil  and 
provision  them  with  bugs  (He- 
miptera),  most  of  which  are 
killed,  not  paralyzed.  The  Bem- 
becidoe,  distinguished  by  the  pro- 
jecting, even  beak-like  upper  lip, 
are  all  diggers,  and  include  our 
largest  solitary-wasp  species. 
Bemhex  spinolcB  (PL  XII,  Fig. 
8),  a  large  black  and  bluish- 
white  banded  form,  shows  an  in- 


FlG. 


703. — Nest -burrow     of    Astata    unicolor. 
(After  Peckham;    natural  size.) 


teresting  variation  from  the  usual  digger-wasp  habits  of  feeding  the  young. 
Throughout  their  entire  larval  life  (two  weeks)  the  female  catches  flies  and 
brings  them  to  the  covered  nest,  having  to  dig  away  each  time  the  loose  soil 


Fig.  704. — Tarantula-killer,  Pepsis  formosa.     (Natural  size.) 

and  to  scrape  it  in  again  as  she  leaves  the  nest.  One  of  the  giant  solitary 
wasps  of  our  country  is  the  powerful  cicada-killer,  Sphecius  speciosus,  i\ 
inches  long,  rusty  black  with  yellow-banded  abdomen.     The  wasp,  attracted 


Wasps,  Bees,  and  Ants 


501 


to  its  prey  by  its  shrill  singing,  pounces  upon  a  cicada,  paralyzes  it  by  a  swift 
stab,  and  then  laboriously  flies  with  or  drags  the  heavy  body  to  the  burrow. 
This  burrow  may  be  a  foot  or  even  more  in  depth,  usually  consisting  of  a 
nearly  vertical  tunnel  for  6  inches,  with  a  sharply  diverging  nearly  horizontal 
part  as  long  as  or  longer  than  the  entrance  one.  Sometimes  instead  of  a  single 
terminal  cell  there  are  several  lateral  cells,  in  each  of  which  one  or  two  cica- 
das are  stored.  Another  familiar  group  of  diggers  are  the  spider-wasps, 
PompiHdae,  mostly  black  or  steely-blue  with  bluish  or  light-bronzy  wings 
(PI.  XII,  Fig.  13).  This  is  a  large  family  including  a  few  guest- wasps 
(Ceropales)  and  a  few  mud-daubers  or  mason- wasps  (Agenia),  as  well  as 
true  diggers,  but  all  of  the  members  of  the  family  which  make  their  own 
nests  provision  them  with  spiders.  The  giant  tarantula-killer,  Pepsis  jor- 
mosa  (Fig.  704),  largest  of  all  our  wasps,  belongs  to  this  family.  It  is  common 
in  California  and  the  southwest,  where  its  sensational  combats  with  the  great 
hairy  tarantulas  (Mygale)  are  often  seen.  It  does  not  always  come  off  vic- 
tor in  these  fights,  or  at  least  conquers  the  tarantula  only  at  the  expense 
of  its  own  life.  After  one  such  long  and  fierce  battle  I  found  both  fighters 
hors  du  combat,  the  tarantula  paralyzed  by  the  wasp's  sting,  but  the  wasp 
dying  from  the  poisonous  wounds  made  by  the  great  fangs  of  the  spider. 

It  is  a  matter  of  much  speculation  how  the  digger-wasps  find  their  nests 
again  after  carefully  covering  them  and  going  off  to  search  for  caterpillars, 
spiders,  bugs,  or  whatever  are  to  be  stored  up  for  the  larvae.  The  Peck- 
hams  have  made  many  interesting  observations  touching  the  problem,  trac- 
ing carefully  the  movements  (Figs.  705  and  706)  and  behavior  of  individuals 


Fig.  705. 

Fig.   705. — Locality  study  of  Cerceris  deserta.     (After  Peckham.) 
Fig.  706. — Locality  study  of  Cerceris  deserta.     (After  Peckham.) 


after  finishing  a  burrow  and  making  ready  to  provision  it.  From  these 
observations  they  conclude  "that  wasps  are  guided  in  their  movements  by 
their  memory  of  localities.     They  go  from  place  to  place  quite  readily  because 


502 


Saw-flies,  Gall-flies,  Ichneumons, 


they  are  familiar  with  the  details  of  the  landscape  in  the  district  they  inhabit. 

Fair  eyesight  and  a  moderately  good  memory  on  their  part  are  all  that  need 

be  assumed  in  this  simple  explanation  of  the  problem." 

In  the  last  of  Sharp's  divisions,  on  the  basis  of  habit,  are  those  solitary 

wasps  that  make  nest-tunnels  in  wood  or  the  stems  of  plants.     In  the  pith 

of  various  kinds  of   cane-bearing  plants,   as   brambles,   blackberries,   etc., 

may  often  be  found  the  tunnels  (Fig.  707),  provisioned  with  plant-lice  or 

other  small  homopterous  bugs,  of  various  small 
wasps  of  the  families  Mimesidffi  and  Pemphredo- 
nidK.  The  Mimesids  have  a  petioled  abdomen 
and  look  like  little  Sphecids;  the  Pemphredonids 
are  shining  black.  The  family  Crabronidse,  a 
rather  large  group  of  solitary  wasps  distinguished 
by  having  only  one  closed  submarginal  cell  in 
the  fore  wings,  includes  many  wood-borers.  Very 
common  in  sumac-branches,  according  to  Com- 
stock,  are  the  nests  of  slender  yellow-banded  Tri- 
poxylon  jrigidiim;  the  cells  are  separated  by  mud 
partitions.  The  Peckhams  found  two  slender- 
waisted,  black  species  of  Tripoxylon  common  near 
Milwaukee,  namely,  T.  albopilosum,  f  inch  long, 
with  tufts  of  snowy-white  hairs  on  the  fore  legs, 
and  T.  rubrocinctum,  a  little  smaller  and  with  a  red 
band  about  the  body.  Although  these  wasps  are 
normally  wood-borers,  they  will  use  convenient 
cavities  in  any  material ;  rubrocinctum  was  found 
using  crevices  in  the  mortar  of  a  brick  house, 
and  the  straw  of  a  stack  where  thousands  of 
the  cut  ends  of  the  straws  offered  attractive 
clean  nesting-holes;   albopilosum  was  found  nest- 

FiG.  707.— Nest -tunnels  of  ing  in  holes  made  by  beetles  in  posts  and  trees, 
two  carpenter -wasps^  A,  ^^^  never  in  straws;  a  third  common  species, 
Monobia  quadridens  (Eume-  i      •      1 

nidje);  B,  Stignms  jraternes  bidentatum,  seemed  to  nest  only  m  burrows  tun- 
(Pemphredonidse).  (After  ^gled  by  itself  in  the  stems  of  plants.  Another 
Comstock:     natural  size.)  ^  •      i.-l.  ^  ^  ^ 

carpenter-wasp,  common    m  the    eastern  states, 

is  the  large  Eumenid  species,  Monobia  quadridens,  which  drills  a  tunnel  in  solid 
wood,  dividing  it  into  cells  by  transverse  partitions  (Fig.  707,  A).  The  species 
of  the  genus  Crabro  make  their  nests  especially  in  the  canes  of  blackberry- 
and  raspberry-bushes.  The  Peckhams  found  that  Crabro  stirpicola  did 
much  of  its  work  at  night,  something  not  observed  in  the  case  of  any  other 
solitary  wasp.  This  species  provisioned  its  cells  with  various  species  of 
flies. 


Wasps,  Bees,  and  Ants  503 

The  social  wasps  all  belong  to  the  single  family  Vespidae,  which  includes 
but  three  genera  of  American  wasps,  of  which  one  is  limited  to  the  Pacific 
coast.     These  three  genera  may  be  distinguished  by  the  following  characters: 

Social  wasps  with  abdomen  broad  and  truncate  at  base  (next  to  thorax)  .  .  Vespa. 

Social  wasps  with  abdomen  spindle-shaped,  tapering  at  both  ends Polistes. 

Social  wasps  with  abdomen  pedunculate,  i.e.,  basal  segment  elongated  to  form  a  stem 
or  peduncle ;   occurring  only  on  Pacific  coast Polybia. 

All  these  wasps  fold  the  wings  longitudinally  when  at  rest,  and  in  all 
there  exist  three  castes  or  kinds  of  individuals  in  each  species,  namely,  males, 
females,  and  sterile  workers.  Like  the  worker  bees,  worker  wasps  are 
winged,  not  wingless,  as  the  worker  ants  are. 

The  "social"  habit,  as  distinguished  from  the  "soHtary"  habit  charac- 
teristic of  all  the  wasps  we  have  so  far  studied,  consists  of  the  founding  and 
maintenance  of  communities  by  the  living  together  in  a  single  group  through 
the  spring,  summer,  and  autumn  of  all  the  offspring,  males,  females,  and 
workers,  of  a  single  fertilized  female,  the  queen.  This  community  is  thus 
a  single  family,  often  indeed  very  large,  which  busies  itself  about  the 
care  of  a  family  nest.  The  nest  may  be  underground  or  suspended  from 
the  branch  of  a  tree,  placed  under  the  eaves  of  a  building  or  otherwise 
supported  above  ground.  It  is  built  of  paper  made  by  moistening  bits 
of  old  wood  with  saliva  and  chewing  them  into  pulp,  and  consists  of  one  or 
more  horizontally  placed  tiers  or  combs  of  cells,  exposed  or  enclosed  by 
paper  envelopes,  in  which  a  single  entrance  and  exit  opening  is  left. 

The  castes  or  kinds  of  individuals  are  not  so  distinctly  recognizable  by 
structural  differences  as  with  the  social  bees  and  the  ants,  but  the  sexual 
forms,  males  and  females,  are  always  obviously  larger  than  the  workers 
(Fig.  709).  The  special  functions  of  the  different  castes  are  (i)  the  mating 
with  the  females  by  the  males;  (2)  the  building  of  the  queen-nest  (the  minia- 
ture early  spring  nest,  see  next  paragraph),  the  gathering  of  food  for  the 
first,  early  spring  generation,  and  the  laying  of  eggs  for  all  the  broods  by 
the  females;  (3)  the  bringing  of  food,  and  the  enlarging  and  building  and 
care  of  the  nest  and  of  the  young  by  the  workers. 

It  has  already  been  mentioned  that  a  community  holds  together  through 
part  of  the  year  only.  The  Ufe-history  of  a  community  is  in  general  outline 
as  follows:  In  the  early  spring  fertiUzed  females'  (queens)  which  have  hiber- 
nated (as  adults)  in  sheltered  places,  as  crevices  in  stone  walls,  under  logs, 
stones,  etc.,  come  out  from  their  winter  hiding-places  and  each  makes  a  small 
nest  (of  the  kind  characteristic  of  its  species,  see  later)  containing  a  few 
brood-cells.  In  each  cell  an  egg  is  laid,  and  food,  consisting  of  insects,  killed 
and  somewhat  masticated,  is  hunted  for  and  brought  to  the  larvae  throughout 
their  brief  life  by  the  queen.     The  larvae  soon  pupate  in  the  cells  and  in  a 


Fig.    708. — Nest    of    Vespa    crabro,    found    in    hollow    oak-tree    on    Long   Island.     (After 
BeutenmuUer.     Natural  size,  2  feet  long  by  7  inches  wide.) 


504 


Saw-flies,  Gall-flies,  Ichneumons,  etc.  505 

few   days  issue   as   winged  wasps.     They  are  exclusively  workers.    These 


^./^ 


Fig.  709. — Vespa  sp.     a,  worker;    b,  female  or  queen.     (After  Jordan  and  Kellogg; 

natural  size.) 

workers    now   enlarge    the    nest,    adding    more    brood-cells    in    which   the 

queen    deposits    eggs.      The    bringing    of 

food  and  care  of  the  young  now  devolve 

on    the    workers.      The    new    or    second 

brood  is  also  composed  of  workers  only, 

and   these  immediately  reinforce   the  first 

brood   in  the  work  of  enlarging  the  nest 

and     building     new     brood-cells.       Thus        -"(^j,  ^-"^^^ 

through    the    summer    several   broods    of  Fig.  710. — Two  workers  of  the  yel- 

workers  are   reared,  until  in  the  late  sum-      low-jacket,  Vespa  sp.    (From  life; 

,      .  ,,       ,  ,  .    .  ,  natural  size.) 

mer  or  early  fall  a  brood  contammg  males 

and  females  as  well  as  workers  appears.  The 
community  is  now  at  its  maximum  both  as  re- 
gards population  and  size  of  nest.  In  the  species 
(Vespa  sp.)  which  make  the  great  ball-like  aerial 
nests  the  community  may  grow  to  number 
several  thousand  individuals.  The  males  and 
females  mate  (presumably  with  members  of 
other  communities),  but  no  more  eggs  are  laid, 
and  with  the  gradual  coming  on  of  winter  the 
males  and  workers  and  many  of  the  females  die. 
There  persist  only  as  survivors  of  each  com- 
munity a  few  fertilized  females;  these  crawl 
into  safe  places  to  pass  the  winter.  Any 
social  wasp  found  in  winter-time  is  thus,  almost 
certainly,  a  queen.  Those  of  the  queens  which 
Fig.  7ii.-CommunaI  nest  of  ^^^^    safely    through    the    long    winter    found 

the  yellow- jacket,  Vespa  sp.   the  communities  which  live  through  the  foUow- 

(Much  reduced.)  jj^g  g^^son. 

The  social  wasps  of  the  genus  Vespa,  the  familiar  yellow-jackets  and 


5o6 


Saw-flies,  Gall-flies,  Ichneumons, 


hornets,  are  the  ones  which  build  the  large  subspherical  nests  familiar  to 
all  outdoor  observers  and  related  to  much  boyish  adventure.  Inside  the 
great  globe  are  several  horizontal  combs  of  brood-cells  in  tiers,  all  enclosed 
by  several  layers  of  wasp-paper  (Figs.  711  and  712).  The  large  bald-faced 
hornet,  V.  maculate,  is  the  best-known  builder  of  the  globe  nests.     The  smaller 


Fig    712. — ^Nest  of  yellow-jacket,   Vespa  sp.,  cut  open  to  show  combs  within. 
(About  one-third  natural  size.) 


yellow-jackets,  V.  germanica  (PL  XII,  Fig.  9)  and  V.  cuneata,  build  in 
hollows  in  stumps  or  stone  fences  or  underground.  Such  protected  or  under- 
ground nests  are  not  as  thoroughly  and  thickly  enveloped  in  paper  as  are 
the  exposed  arboreal  globe  nests.  The  miniature  queen-nests  (Fig.  713) 
of  the  Vespae,  with  the  single  little  brood-comb  inside,  may  often  be  found 
by  careful  searching  in  spring. 

The  long-bodied  blackish  social  wasps  of  the  genus  Polistes  (PL  XII, 
Fig.  2;  also  Fig.  714)  build  single  exposed  horizontal  combs  out  of  wasp-paper 
(chewed  wood)  which  are  attached  to  the  under  side  of  porch  roofs,  eaves, 
ceilings  of  outbuildings,  etc.,  by  a  short  central  stem.  The  little  comb 
made  by  the  queen  may  contain  but  half  a  dozen  cells,  but  after  the  workers 
hatch  many  other  cells  are  added  around  the  margin.  But  the  nest  and 
community  never  compare  in  size  and  numbers  with  the  large  commu- 
nities of  Vespa.     The  hibernating    queens  of  Polistes  often  seek   hiding- 


Wasps,  Bees,  and  Ants 


507 


places  in  our  houses.  Wasps  of  this  genus  are  not  infrequently  parasitized 
by  the  remarkable  Stylopid  beetles  (Fig.  403)  Xenos,  of  which  an  account  is 
given  on  p.  295. 


^'l^^ 


Fig.  713. — Queen-nest  of   yellow-jacket,    Vespa  sp.;    specimen  at   right  in  normal  con- 
dition;   at   left   cut   open   to   show  brood-cells.     (Natural   size.) 

Only  one  species  of  Polybia  occurs  in  the  United  States,  and  that  one, 
P.  fiavitarsis  (PL  XII,  Fig.  12),  is  found  only  on  the  Pacific  coast.  It  is 
common  in  Cahfornia.  It  is  readily  distinguishable  from  the  other  social 
wasps  by  its  slender  pedunculate  basal  abdominal  segment  and  the  small 
button-like  shape  of  the  rest  of  the  abdomen.  It  builds  a  single-comb, 
unenveloped  nest,  like  that  of  Polistes,  but  not  reaching  the  diameter  of 
the  broad  disk-like  Polistes  comb. 

It  has  been  mentioned  that  the  social  wasps  feed  their  young  (larvae) 
chewed  insects.  Differing  from  most  of  the  solitary  wasps,  the  social  kinds 
do  not  store  up  food  for  the  young,  but  collect  and  bring  it  constantly  through 
the  life  of  the  larvae,  a  period  of  from  eight  to  fifteen  days.  This  food  con- 
sists of  the  partially  masticated  remains  of  various  insects  pursued  and  killed 
by  the  queea  or  workers.  The  queen  brings  food  only  for  the  larvae  of  the 
first  small  spring  brood. 

The  adult  wasps  are  more  catholic  as  regards  the  palate;  they  feed  on 
insects  or  decomposing  animal  substances — fish  especially  attract  them — 
and  on  exposed  sweet  substances,  as  sirups,  preserved  fruits,  etc. 

The  paper-making  and  nest-building  are  industries  whose  details  can 
only  be  touched  on  in  our  limited  space.     The  paper  is  not  only  made  of 


5o8 


Saw-flies,  Gall-flies,  Ichneumons, 


chewed-up  bits  of  weathered  wood  gathered  from  old  fences  or  outbuildings; 
"round  the  swampy  edges  of  ponds  or  in  wet  ditches  wasps  may  be  seen 
gathering  tough  herbaceous  filaments  which  they  felt  up  into  a  texture 
stronger  and  better  able  to  resist  the  wind  and  rain  than  a  paper  made  of 

wood  scrapings."    The  moulding 


of  the  pulp  at  the  nest  has  been 
observed  carefully  by  Ormerod 
in  the  case  of  two  English  spe- 
cies of  Vespa  "It  appeared," 
says  Ormerod,  "that  when  a 
wasp  came  home  laden  with 
building  materials  she  did  not 
immediately  apply  these,  but  flew 
into  the  nest  for  about  half  a 
minute,  for  what  purpose  I  could 
not  ascertain.  Then  emerging 
she  promptly  set  to  work. 
Mounted  astride  on  the  edge  of 
one  of  the  covering  sheets,  she 
pressed  her  pellet  firmly  down 
with  her  fore  legs  till  it  adhered 
to  the  edge,  and^  walking  back- 
wards, continued  this  same  pro- 
cess of  pressing  and  kneading  till 
the  pellet  was  used  up,  and  her 
track  was  marked  by  a  short  dark  cord  lying  along  the  thin  edge  to  which  she 
had  fastened  it.     Then  she  ran  forwards,  and,  as  she  returned  again  back- 


FiG.  714. — Pohstes  sp.  a.  nest;  b,  young  larva; 
c,  older  larva;  d,  pupa;  e,  adult.  (All  one 
and  one-half  times  natural  size  except  nest, 
which  is  much  reduced.) 


Tig.  715. — The   single-comb   nest   of   a   hornet,   Polistcs  sp.     (One-half   natural  size.) 


wards  over  the  same  ground,  she  drew  the  cord    through  her  mandibles, 
repeating  this  process  two  or  three  times  till  it  was  flattened  out  into  a  little 


Wasps,  Bees,  and  Ants  509 

strip  or  ribbon  of  paper,  which  only  needed  drying  to  be  undistinguishable 
from  the  rest  of  the  sheet  to  which  it  had  been  attached.  And  then  she  gravely 
retired  into  the  nest  again. 

"By  this  means  of  marking  different  wasps  it  was  evident  that  each  wasp 
had  not  a  place  of  her  own  to  work  at,  but  that  all  worked  anywhere  and 
anyhow.  And  this  whether  they  were  engaged  in  adding  to  the  structure 
or  in  removing  what  had  been  built  previously.  So,  a  wasp  wliich  had  been 
collecting  white  fibers  joined  her  quota  to  what  had  been  built  by  a  wasp 
who  had  gathered  materials  of  a  darker  color,  giving  a  variegated  appearance 
to  the  work.  Further,  it  seemed  clear  that  only  the  young  wasps  built, 
probably  because  they  only  had  the  power  of  secreting  mucus  in  sufficient 
quantity  for  working  up  the  dry  fibers  into  a  pulp.  This  was  inferred  from 
the  generally  larger  size,  and  the  smooth  ends  of  the  wings,  of  the  wasps 
which  were  examined  while  thus  engaged.  Wasps  grow  smaller  as  they 
grow  older,  and  the  ends  of  their  wings  get  tattered  with  advancing  days. 

"By  the  conjoint  labors  of  all  these  busy  workers,  here  a  Httle  and  there 
a  httle,  the  nest  grows.  The  work  of  one  week  may  have  to  be  removed 
the  next  week,  to  make  way  for  modern  improvements  and  for  the  require- 
ments of  the  growing  city;  and,  as  we  have  seen,  it  has  nearly  all  to  be  done 
twice  over.  But  wasps  work  very  hard,  and  the  nest  grows  visibly  day  by 
day.  The  little  egg-shell  in  which  it  began  is  lost  in  the  changes  which  the 
top  of  the  nest  undergoes.  The  slight  strap  from  which  it  hung  is  now  quite 
inadequate  to  sustain  the  daily  increasing  weight,  and  new  points  of  attach- 
ment are  sought  to  projecting  roots,  or  stones,  or  branches.  Sometimes 
a  branch  runs  all  through  a  nest,  materially  adding  to  the  difficulty  of  its 
capture.  Or,  failing  these,  the  original  point  of  support  is  strengthened 
by  layer  upon  layer  of  paper,  rubbed  smooth,  and  thickly  coated  with  wasp- 
gum,  to  preserve  so  vital  a  point  from  all  accidents  of  wind  and  weather. 
The  regular  arrangement  of  the  upper  part  of  the  nest  is  much  disturbed 
in  the  course  of  these  events,  and  the  top  of  one  nest  comes  to  look  very  like 
the  top  of  another.  But  at  the  bottom,  at  the  growing  part  of  the  nest,  the 
different  architectural  instincts  of  the  several  species  are  displayed  quite 
to  the  last.  The  number  of  layers  of  paper  employed  to  form  the  nest-cover 
varies  with  the  species,  with  the  season,  and  with  the  circumstances  under 
which  the  nest  has  been  built.  Sometimes  the  case  is  so  thin  that  the  comb 
shows  an  edge  through  the  wall,  while  sometimes  it  is  composed  of  as  many 
as  a  dozen  layers.  But.  however  the  thickness  of  the  walls  may  vary,  as  a 
rule  so  invariable  as  to  have  been  adopted  as  a  means  of  classification,  the 
combs  of  the  nests  of  the  Vespae  have  no  connection  with  the  outer  case, 
except  at  the  top  of  the  nest.  The  comb  and  the  case  are  mutually  inde- 
pendent and  separate  from  each  other. 


5IO  Saw-flies,  Gall-flies,  Ichneumons, 

"The  combs,  unlike  those  of  the  honey-bee,  are  laid  horizontally,  stage 
below  stage,  each  hanging  from  the  one  immediately  above  it,  without  any 
reference  to  the  rest  of  the  series.  The  two  or  three  uppermost  stages  of 
comb,  into  which  the  first  rudimentary  cells  have  been  expanded,  are,  in 
course  of  time,  worked  into  the  case  of  the  nest  at  their  edges.  And  the 
cells  are  cut  down  to  allow  room  for  the  wasps  to  camp  on  the  upper  surface 
of  the  comb  beneath.  Wasps  do  not  stand  cold  and  wet,  so  a  shelter  is 
here  provided  for  them,  where  they  may  be  kept  dry  and  warm,  without 
interfering  with  the  comfort  and  safety  of  the  larvae  in  the  lower  stages.  Inci- 
dentally another  advantage  is  gained  by  this  arrangement.  For  the  fabric 
of  the  nest  is  thus  materially  strengthened,  by  substituting,  at  this  vital  point, 
a  hard,  dry,  light  flooring  for  the  loose,  damp  comb,  which  is  almost  ready 
to  fall  to  pieces  by  its  own  weight. 

"When  a  new  stage  is  to  be  constructed,  the  wasps  begin  by  raising  the 
walls  of  two  or  three  adjoining  cells  in  the  center  of  the  lowest  comb.  From 
these  diverging  roots  a  round  cord  is  drawn  out,  as  it  were,  on  the  end  of 
which  little  cells  are  made,  just  as  on  the  end  of  the  footstalk  from  which 
the  nest  originally  sprung.  As  each  cell  takes  shape  an  egg  is  deposited  in  it, 
so  as  to  lose  no  time;  and  while  its  walls  are  gradually  rising  the  comb  is 
gradually  spreading,  by  concentric  rings  of  cells.  The  mother  wasp  follows 
close  on  the  traces  of  the  worker,  and  the  circles  of  larvas  of  the  same  age 
show  the  system  on  which  the  comb  has  been  made.  As  the  comb  spreads, 
new  stays  are  let  down  to  support  the  weight  increasing  with  the  width. 
Meanwhile  the  expansion  of  the  case  keeps  exact  pace  with  the  lateral  growth 
of  the  comb;  the  old  case  is  nibbled  away  within,  and  new  paper  is  laid 
on  outside,  so  as  to  make  room  all  around  the  edge.  And  before  each  stage 
has  attained  its  full  dimensions,  another  has  been  commenced  below  it, 
just  in  the  same  manner." 

BEES. 

In  popular  repute  there  are  just  two  kinds  of  bees,  honey-bees  and  bumble- 
bees. Actually  there  is  a  host  of  kinds,  many  of  them  small  and  hardly 
noticeable,  and  perhaps  even  when  seen  mistaken  for  other  insects.  Still, 
all  the  bees  have  such  a  "bee-y"  manner  and  general  appearance  that  such 
mistakes  can  only  be  made  by  the  most  casual  of  observers.  There  are  indeed 
a  few  slender-bodied  small  bees  that  suggest  wasp  more  than  bee  perhaps 
in  general  seeming;  and  there  are  not  a  few  kinds  of  flies  (Diptera),  espe- 
cially the  fiower-fiies  (Syrphidae),  bee-flies  (Bombyliidae),  and  certain  robber- 
flies  (AsiHdae)  that  resemble  bees  quite  sufficiently  to  be  often  mistaken  for 
them.  Careful  inspection  will  quickly  reveal  the  deception;  by  showing 
the  presence  of  but  a  single  pair  of  wings  on  all  these  bee-mimicking  flies. 


Wasps,  Bees,  and  Ants 


511 


While  bumblebees  and  honey-bees  are  the  everywhere  common,  con- 
spicuous, and  familiar  representatives  of  the  great  superfamily  of  bees,  the 
Apoidea,  they  include  but  a  fraction  of  the  nearly  one  thousand  different 
kinds  of  bees  so  far  recorded  as  occurring  in  this  country.  Indeed,  all  of 
our  social  honey-bees,  although  variously  called  German,  Italian,  Carniolans, 
etc.,  belong  to  a  single  species,  and  that  not  a  native  but  an  imported  one. 
Of  the  bumblebees  a  few  more  than  fifty  native  species  are  known.  Besides 
the  hive-bee  and  the  bumblebee,  then,  there  are  nearly  a  thousand  other  bees 
in  the  American  fauna  to  be  taken  into  account.  As  among  the  wasps, 
there  are  parasitic,  guest,  solitary,  and  social  kinds  of  bees;  and  as  among 
the  solitary  wasps  there  are  diggers,  miners,  carpenters,  and  masons,  so 
also  there  are  miner-,  carpenter-,  and  mason-bees.  There  are  bees  which 
lay  their  eggs  in  the  nests  of  other  bees,  so  that  their  young  feed  on  the  stored 
food  of  the  hosts;  there  are  bees  which  make  nest-burrows  in  the  ground, 
others  that  tunnel  in  stems  of  plants  and  wood,  others  that  mould  clay  cells, 
others  that  cut  leaves  and  line  their  nest  bored  into  the  pith  of  canes,  others 
that  hve  in  communities  underground  which  break  up  each  year,  and  finally, 
most  conspicuous  among  them  all,  there  is  the  familiar  species  that  lives  in 
great  persistent  communities  in  hives  and  hollow  trees. 

All  these  thousand  bee  kinds  can  be  conveniently  and  naturally  primarily 
grouped  into  two  divisions,  the  short-tongued  bees  (Fig.  716)  (those  with 
a  short,  broad,  flattened,  spoon-Hke  tongue) 
and  the  long-tongued  bees  (Fig.  717)  (those  with 
a  slender,  elongate,  subcylindrical  flexible  tongue). 
In  the  older  books  these  groups  were  called  fami- 
lies, namely  the  Andrenidae  (short-tongued  bees) 
and  the  Apidas  (long-tongued  bees),  but  modern 
systematists,  while  still  recognizing  the  con- 
venience of  this  primary  grouping,  classify  bees 
into  a  dozen  families  or  more.  For  the  purposes 
of  this  book,  however,  we  shall  recognize  a  group- 
ing on  structural  characters  into  simply  two  main 
divisions,   short-tongued    and    long-tongued,    and 

another   grouping,    on   a   basis   of   habit   and  of   Fig^  716.— Mouth-parts  of  a 
psychologic  development,  into  three  general  groups, 
namely,  sohtary  bees,  gregarious  bees,  and  com- 
munal bees. 

The  structural  characters  in  which  all  bees 
agree  among  themselves  and  differ  from  the  other  Hymenoptera  are  the  pos- 
session of  branched  or  feathery  hairs  on  the  head  and  thorax  and  of  swollen 
or  expanded  and  flattened  tarsal  segments:  the  pronotum  does  not  extend 
back  to  the  tegulae  of   the  wings  as  is  the  case  with  the  Sphecoid  wasps, 


short-tongued  bee,  Prosopis 
piibescens.  Note  short, 
broad,  flap  -  Hke  tongue 
(glossa  of  labium).  (After 
Sharp;    much  enlarged.) 


512 


Saw-flies,  Gall-flies,  Ichneumons, 


but  not  with  the  Vespoid  wasps,  including  the  social  kinds.  The  mouth 
in  all  bees  is  provided  with  a  well-developed  pair  of  strong  mandibles, 
either  sharp  and  toothed  for  digging  in  the  ground  or  tunneling  in  wood, 
or  smooth  and  spoon-like  for  moulding  wax.  The 
food  of  both  adults  and  larva  is  always  flower- 
nectar  (made  into  honey)  and  pollen  (for  the  very 
young  larvae  a  predigested  food,  bee-jelly,  is 
regurgitated  by  the  nurse  workers)  and  never  in- 
sects, paralyzed,  killed,  or  chewed,  as  with  the 
wasps.  The  bee  mouth  is  therefore  fitted  for  the 
lapping  or  sucking  up  of  nectar,  as  well  as  for 
scraping  off  and  crushing  pollen.  The  maxilla? 
and  labium  are  more  or  less  intimately  joined 
by  membranes  and  chitinous  bars  and  are  capable 
of  much  variety  of  movement  in  the  way  of  fold- 
ing, retraction,  and  extension.  The  antennae  are 
elbowed  and  their  terminal,  smooth,  cylindrical 
segments  are  provided  with  numerous  sense-pits 
and  papillae,  special  organs  of  olfactory  and  tactile 
perception.  The  compound  eyes  are  large  and 
sight  is  undoubtedly  better  than  in  most  insects. 
There  are  only  male  and  female  individuals  in 
the  solitary  species,  both  winged,  and  the  females 
provided  with  a  sting;  in  the  social  species 
(bumble-  and  honey-bees)  there  are  in  addition 
worker  individuals  (females  of  arrested  sexual 
development  but  with  special  structural  develop- 
ment) which  are  also  winged  and  furnished  with 
a  sting.  The  eggs  are  laid  in  cells  in  the  ground,  in  plant-stems,  in  logs. 
or  posts,  or  made  of  wax  (hive-bee)  or  hollowed  out  of  a  food-mass  of 
pollen  (bumblebees),  and  the  hatching  larvae  find  stored  up  for  them  a  suf- 
ficient food-supply  for  their  larval  life,  or  they  are  brought  food  constantly 
during  this  Hfe.  These  larvae  are  footless,  white,  soft-bodied  grubs,  which 
pupate  in  their  cells.  The  issuing  imagines  gnaw  their  way  out  of  the 
cells. 

Of  the  short-tongued  bees  all  are  solitary  or  gregarious;  of  the  long- 
tongued  most  are  solitary,  but  a  few,  the  bumble-  and  the  honey-bee,  live  in 
communities.  I  shall  give  an  account  of  a  few  of  the  more  interesting  or 
more  famihar  kinds  of  bees,  illustrating  the  various  typical  habits  of  nest- 
building  as  well  as  the  gradually  progressive  tendency  toward  that  speciali- 
zation of  life,  communism,  exemplified  in  its  extreme  condition  by  the  hive- 
bee. 


-Mouth-parts  of 
a  long-tongued  bee,  An- 
thophora  pilipes.  Note 
greatly  extended  tongue 
(glossa  of  labium).  (After 
Sharp;    much  enlarged.) 


Wasps,  Bees,  and  Ants 


513 


F- 


H 


The  hairy,  medium-sized  mining-bees  of  the  short-tongued  genus  Col- 
letes  dig  short  vertical  burrows  in  the  ground  which  they  hne  internally  with 
a  sort  of  slime  that  dries  to  a  substance  like  gold-beater's  skin;  they  partition 
the  burrow  into  six  to  ten  cells  in  each  of  which  is  deposited  an  egg,  together 
with  a  store  of  food,  pollen,  and  honey  mixed.  Colletes  has  the  under-lip 
bilobed  hke  that  of  wasps  and  is  evidently  one  of  the  lowest  of  the  bees. 
Prosopis  is  a  short-tongued  genus  of  nearly  hairless, 
small,  coal-black  bees  which  tunnel  into  the  stems  of 
brambles  and  other  plants,  or  dig  burrows  in  the 
ground,  or  make  cells  in  crevices  in  walls;  the  cells  are 
always  lined  with  a  silken  membrane,  and  the  stored 
food  is  more  liquid  than  usual  with  bees. 

The  dainty  little  blue  or  green  carpenter-bees  of  the 
long-tongued  genus  Ceratina  are  common  and  wide- 
spread; their  nests  are  tunnels  in  twigs  and  canes  of 
sumac,  brambles,  and  other  plants  (Fig.  718).  Corn- 
stock  writes  of  the  nest-building  of  the  species,  C.  dupla, 
as  follows:  "She  always  selects  a  twig  with  a  soft  pith 
which  she  excavates  with  her  mandibles,  and  so  makes  a 
long  tunnel.  Then  she  gathers  pollen  and  puts  it  in 
the  bottom  of  the  nest,  lays  an  egg  on  it,  and  then 
makes  a  partition  out  of  pith  chips,  which  serves  as  a 
roof  to  this  cell  and  a  floor  to  the  one  above  it.  This 
process  she  repeats  until  the  tunnel  is  nearly  full,  then 
she  rests  in  the  space  above  the  last  cell,  and  waits  for 
her  children  to  grow  up.  The  lower  one  hatches  first; 
and,  after  it  has  attained  its  growth,  it  tears  down  the 
partition  above  it,  and  then  waits  patiently  for  the  one 
above  to  do  the  same.  Finally,  after  the  last  one  in  the 
top  cell  has  matured,  the  mother  leads  forth  her  full- 
fledged  family  in  a  flight  into  the  sunshine.  This  is 
the  only  case  known  to  the  writer  where  a  solitary 
bee  watches  her  nest  till  her  young  mature.  After 
the  last  of  the  brood  has  emerged  from  its  cell,  the  substance  of  which  the 
partitions  were  made,  and  which  has  been  forced  to  the  bottom  of  the  nest 
by  the  young  bees  when  making  their  escape,  is  cleaned  out  by  the  family, 
the  old  bee  and  the  young  ones  all  working  together.  Then  the  nest  is  used 
again  by  one  of  the  bees.  We  have  collected  hundreds  of  these  nests,  and, 
by  opening  different  nests  at  different  seasons  have  gained  an  idea  of  what 
goes  on  in  a  single  nest.  There  are  two  broods  each  year.  The  mature 
bees  of  the  fall  brood  winter  in  the  nests." 

Other  familiar  carpenter-bees  are  the  great  black  Xylocopas  (PI.  XII, 


15 


Fig.  718. — Nest-tun- 
nel of  carpenter- 
bee.  (Natural  size.) 


5H 


Saw-flies,  Gall-flies,  Ichneumons, 


Fig.  7),  They  are  as  large  as  biiinblebees  and  with  their  heavy  thick 
body  and  black  color  look  much  like  them;  they  have 
the  body  more  flattened  and  less  hairy,  however,  and  the 
hind  legs  of  the  females  are  never  provided  with  a 
"corbiculum,"  or  pollen-basket  (a  concave  smooth 
place  bounded  on  each  side  by  a  row  of  long  stiff  curv- 
ing hairs),  but  are  covered  by  a  stiff  brush  of  short 
hairs.  These  giant  bee-carpenters  tunnel  into  solid 
wood  for  a  foot  or  more,  dividing  the  burrow  into  a 
series  of  cells  by  partitions  made  of  small  chips  stuck 
together.  They  are  common  all  over  the  country, 
"choosing  in  civilized  regions  fence-posts  and  boards." 
Certain  very  large  species  make  their  nests  in  the 
great  fallen  sugar-pines  and  yellow  pines  of  the  Sier- 
ran  forests  and  are  among  the  most  characteristic  in- 
sects of  the  giant-tree  forests. 

The  long-tongued  family  Megachilidae  includes  a 
number  of  common  and  interesting  bees,  most  familiar, 
perhaps,  being  the  mason-bees  (Osmia),  the  potter-bees 
(Anth'dium),  and  the  leaf-cutters  (Megachile).  The 
Osmias  are  metallic,  black,  blue,  or  green,  and  make 
their  nests   of  clay  and   sand,  moulded  into  cells,  and 

built  in  already  existing  cavities  in  stone  walls,  old   posts,  tree-trunks,  etc., 

or   in   tunnels   bored  by  the  bee   in   plant-stems  and  twigs.      The  various 

species  of  Anthidium  are  black   and  rufous,  or  rufous 

and  yellow,  with  the  abdomen  always  banded  or  spotted 

with  yellow,  white   or  rufous.      The  females  normally 

construct    globular    cells   rather  like  the  earthen  vases 

of  Eumenes  (Fig.  701),  but  made  of  the  resinous  exuda- 
tions of  pine-trees  and  other  plants,  or  dig  burrows  in 

the   soil    which    they   line    with    down   stripped   from 

pudescent  or  woolly-leafed    plants.      Both    Osmia  and 

Anthidium    sometimes   make    their    nests    in    deserted 

snail-shells!     The  leaf-cutting  bees   (Figs  719  and  720) 

are  usually  carpenters  as  well  as  tailors;  that  is,  they  first 

bore  a  tunnel  in  some  plant-stem  or  in  wood,  and  then 

cut  out  pieces  of  green  leaves  with  which  they  line  the 

tunnel  and  partition  in  such  a  way  as  to  form  a  series 

of  thimble-shaped  cells  each  partially  filled  with  a  paste 

of  pollen  and  nectar  on  which  an  egg  is  deposited.     The 

pieces  of  leaf  are  fastened  together  with  a  gummy  secretion  from  the  mouth 

of  the  bee.     Comstock  has  found    leaf-cutter    nests  in  a  "crack  between 


Fig.  719. —  Nest  of 
leaf-cutter  bee,  Me- 
gachile anthracina> 
(After Sharp;  some- 
what enlarged.) 


Fig.  720. — Single  cell 
in  nest  of  leaf-cut- 
ter bee,  Megachile 
anthracina.  (After 
Sharp;  somewhat 
enlarged.) 


Wasps,  Bees,  and  Ants  5 1  5 

shingles  on  a  roof,  beneath  stones  lying  on  the  ground,  and  in  Florida  in  the 
tubular  leaves  of  a  pitcher-plant." 

Other  common  genera  of  solitary  long-tongued  bees  are  Anthophora 
(PI.  XII,  Fig.  11),  the  species  of  which  are  hairy  and  robust-bodied,  looking 
indeed  much  hke  small  bumblebees,  Melissodes  and  Synhalonia  with  very 
long  antennae,  rather  like  honey-bees  in  general  appearance,  and  others 
of  the  great  family  Anthophoridae.  All  these  bees  agree  in  general  habits 
with  those  already  described,  but  every  species  presents  an  opportunity  for 
interesting  and  valuable  work  by  amateurs  and  nature-lovers  in  observing 
precisely  its  nest-building  habits  and  life-history.  No  more  attractive 
opportunity  for  outdoor  observers  offers  than  that  of  the  field  study  of  the 
sohtary  bees. 

As  mentioned  at  the  beginning  of  the  discussion  of  the  solitary  bees,  some 
species  are  parasitic  or,  more  properly  named,  guest  or  inquiline  in  habit. 
That  is,  the  females  of  these  species,  instead  of  building  a  nest-burrow  of 
their  own  and  storing  it  with  food,  lay  their  eggs  in  the  nest-burrows  of  other 
bees,  so  that  the  larvae  on  hatching  will  be  able  to  feed  on  the  supplies  stored 
up  by  the  host-bee.  This  habit  is  not  confined  to  a  few  species,  but  is  com- 
mon to  a  surprisingly  large  number  of  solitary  bees.  Two  entire  families, 
including  a  hundred  species  of  North  American  bees,  are  exclusively  composed 
of  parasitic  bees  (in  addition  a  third  parasitic  family,  an  offshoot  of  the 
bumblebees,  is  mentioned  in  connection  with  the  account,  later,  of  the  social 
bees).  These  two  families  are  the  cuckoo-bees,  Nomadidae,  mostly  bright- 
colored  species,  metallic  blue  or  green  with  the  abdomen  spotted  or  banded 
with  yellow  or  white,  and  the  Stelidae,  differing  structurally  from  the  cuckoo- 
bees  by  having  only  two,  instead  of  three,  submarginal  cells  in  the  wings. 
Ashmead  believes  that  the  Nomadidae  are  descended  from  the  Anthophoridae, 
and  the  Stelidae  from  the  Megachilidae,  the  parasitic  habit  having  arisen 
independently  in  the  two  groups.  Howard  mentions  the  interesting  fact 
that  the  cuckoo-bees  seem  not  only  to  be  tolerated  by  their  hosts,  but  that 
in  some  cases  it  has  been  observed  that  enough  food  is  stored  by  the  host- 
bee  to  enable  the  larvae  of  both  host  and  guest  to  complete  their  development 
side  by  side  and  to  issue  simultaneously  as  adult  bees.  It  may  indeed  be 
found,  as  has  been  discovered  in  numerous  other  cases  of  commensal  life, 
that  the  cuckoo-bee  gives,  in  some  way,  aid  to  the  host,  so  that  the  living 
together  is  mutually  advantageous. 

With  the  wasps  there  are  no  transition  stages,  among  living  forms,  between 
a  strictly  solitary  life,  where  each  female  makes  her  own  independent  nest- 
burrow,  lays  an  egg  in  it  and  stores  it  with  food,  or  brings  food  to  the  larva 
through  its  life,  and  the  social  or  communal  life  exhibited  by  the  yellow- 
jackets  and  hornets,  where  many  females  (of  arrested  sexual  development, 
although  not  always  to  such  a  degree  as  to  be  actually  incapable  of  producing 


5i6 


Saw-flies,  Gall-flies,  Ichneumons, 


fertile  eggs)  called  workers  combine  to  build  a  common  nest  and  numerous 
brood-cells,  in  which  eggs  are  deposited  by  a  single  queen  female,  the  mother 
of  the  whole  community.  With  this  division  of  labor  has  come  to  exist  a 
certain  differentiation  of  structure,  manifest  in  a  difference  in  size  and  in  some 
anatomical  details  between  the  working  females  and  the  egg-laying  female. 

But  with  the  bees  certain  interesting  gradations  in  domestic  economy 
or  insectean  sociology  exist  which  throw  some  hght  on  the  possible  line 
of  progression  or  specialization  from  strictly  solitary  to  strictly  communal 
hfe.  Numerous  technically  "solitary"  bees  show  a  marked  gregariousness, 
a  fondness,  as  it  were,  for  the  company  and  society  of  other  individuals  of 
their  kind.  This  is  chiefly  manifested  in  the  building  of  many  nest-burrows 
close  together,  forming  a  sort  of  village  or  colony  of  homes,  each  home  belong- 
ing to  a  single  female,  built  by  her,  provisioned  by  her,  and  the  young  issuing 
from  it  her  own  offspring,  but  all  these  homes  belonging  to  individuals  of 
one  species  of  gregarious  or  social  inclination.     Near  Stanford  University, 


Fig.  721. — Diagrams  of  nest -burrows  of  short-tongued  mining-bees.    B,  nest  of  Andrena; 
A,  compound  nest  of  Halictus. 

in  a  roadside  cutting  exposing  a  clayey  bank,  lived  a  few  years  ago  a  great 
colony  of  the  large  mining-bee  Anthophora  stanjordiana,  the  vertical,  open- 
mouth  nest-burrows  set  about  as  closely  as  they  could  be  without  breaking 
into  each  other.  This  bee  does  not  store  up  food  in  the  nest,  but  brings  it 
to  the  larva,  the  burrow  not  being  closed.     The  whole  colony  covered  but  a 


Wasps,  Bees,  and  Ants  5 1 7 

few  square  yards  of  the  many  yards  of  exposed  surface.  The  nest-tunnels 
were  capped  by  curious  httle  chimneys,  mostly  curving  so  as  to  present  the 
opening  not  directly  upward,  exposed  to  rain,  but  to  one  side  or  almost  down- 
ward, thus  preventing  the  flooding  of  the  open  burrows  by  water.  Similar 
villages  or  colonies  are  made  by  the  little  short-tongued  mining-bees  of  the 
genus  Andrena.  Comstock  has  noted  Andrena  villages  covering  only  one 
square  rod  of  ground  that  included  several  thousand  nests,  and  he  received 
from  a  correspondent  "a  description  of  a  collection  of  nests  of  this  kind 
which  was  fifteen  feet  in  diameter,  and  in  the  destruction  of  which  about 
2000  bees  were  killed — a  terrible  slaughter  of  innocent  creatures." 

A  step  farther  in  this  social  tendency  is  exhibited  by  the  smallest  of  all 
our  mining-bees,  the  tiny  little  short-tongued  bees  of  the  genus  Halictus, 
the  various  species  measuring  from  ^\  to  j\  of  an  inch  in  length.  While  each 
female  forms  her  own  nest-cells,  lays  eggs  in  them,  and  provisions  them,  she 
is  one  of  a  number  of  females  that  work  together  to  build  a  common  vertical 
tunnel  with  single  external  opening,  along  the  sides  of  which  the  various 
cells  are  arranged.  In  this  way  one  entrance  and  one  corridor,  built  and 
used  by  several  individuals  in  common,  serve  to  give  access  to  several  dis- 
tinct homes,  i.e.,  nest-cells.  These  groups  of  homes  with  common  corridors 
and  openings  are  placed  thickly  together  in  populous  sand-bank  colonies. 
Thus,  as  Comstock  aptly  puts  it,  "while  Andrena  builds  villages  composed 
of  individual  houses,  Halictus  makes  cities  composed  of  apartment-houses." 

The  next  stage  exhibited  among  present-day  bees  in  this  progressive 
specializing  of  the  gregarious  tendency  is  the  condition  under  which  the 
bumblebee  lives.  This  is  a  long  leap  from  the  apartment-house  life  of  Halic- 
tus, and  does  not  explain  how  the  differentiation  into  castes,  i.e.,  the  estab- 
lishment of  the  worker  (rudimentary  female)  caste,  composed  in  some 
cases  of  two  distinct  sizes,  worker  majors  and  worker  minors,  has  come 
about.  If  we  could  but  know  the  intermediate  sociologic  stages  which  were 
exhibited  by  bees  now  extinct  (or,  if  living,  not  yet  discovered),  but  that  cer- 
tainly existed  not  very  long  ago  (as  geologic  time-reckoning  goes),  the  mar- 
velous division  of  labor,  differentiation  of  structure,  and  commensal  inter- 
dependence of  individuals  displayed  by  the  honey-bees  would  be  divested 
of  much  of  its  mystery. 

The  bumblebees  possess  a  domestic  economy  wholly  like  that  of 
the  social  wasps  (yellow -jackets  and  hornets).  In  each  species  there  are 
three  kinds  of  individuals,  males,  fertile  females,  and  workers  (infertile 
females)  which  are  sometimes  of  two  constant  sizes,  called  worker  majors 
and  worker  minors.  The  workers  "are  all  distinctly  smaller  than  the  fertile 
females  and  usually  differ  somewhat  in  marking  (Fig.  723).  The  only  indi- 
viduals to  over-winter  are  fertilized  females,  queens,  which  hibernate  as 
queen  v.^asps  do  in  sheltered  places,  as  crevices  in  stone  walls,  holes  in  the 


5.8 


Saw-flies,  Gall-flies,  Ichneumons, 


ground,  in  hollow  trees  or  under  leaves,  etc.      When  spring  comes,  each 

queen  finds  some  deserted  mouse's  hole,  mole's  burrow,  or  other  cavity  in 

the  ground,  or  digs  one  herself;  she  then  gathers  some  pollen  and  honey 
which  she  brings  to  the  hole,  making  there  a  ball- 
like mixed  pasty  mass  of  it.  On  this  lump  of  food 
she  deposits  a  few  eggs,  from  half  a  dozen  to  a 
score,  and  then,  while  waiting  for  their  hatching,  brings 
more  food  and  deposits  more  eggs.  The  hatching 
larvae  feed  on  the  pollen  and  honey  paste,  sepa- 
rating and  eating  out  one  or  more  considerable 
cavities  in  it.  When  full-grown  each  spins  a  silken 
cocoon  within  which  it  pupates.  The  issuing  bees 
are  all  workers.  They  enlarge  the  nest-burrow, 
if  necessary  bring  more  food,  the  queen  lays  more 
eggs,  and  so  for  several  broods.  The  larvae  ready 
to  pupate  are  enclosed  in  waxen  cells,  sometimes 
several  in  a  single  cell,  by  the  workers  (except  in  the 
first  brood,  when  there  are  no  workers  to  make 
the  cells).  A  full-sized  bumblebee's  nest  may  be  as 
large  as  one's  head,  composed  of  a  cluster  of  large 

Fig.  ;y22. Bumblebee  at   irregular  waxen  cells,  mostly  containing  brood  (larvae 

(From   or  pupae),  but    some    containing   pollen    and    a  few 
honey.     All  may  be  enclosed  in  a  loose  covering  of 

hay  or  bits  of   stems   and   roots,  the  whole   lying  at  the   bottom  of  a  deep 

or   shallow  tunnel.     There   are   usually  two  or   more  openings  to   the  nest. 

In  the  late  summer  and  fall  males  and  females  are  reared,  issue  from  the 

nest  and  mate.     With  the  oncoming 

of    cold    weather    the    males    and 

workers  gradually  die,  leaving  a  few 

fertilized    young     queens     to     live 

through  the  winter.     These  are  the 

founders  of  next  year's  communities. 
All    the    bumblebees    belong    to 

the  genus  Bombus  (family  Bombidae) , 

long-tongued    bees  with   two  apical 

spurs  on  the  hind   tibiae  and  with  a 

single  submarginal  cell  in   the  front 

wings.     Their  big  velvety  black-and- 

yellow  bodies   and  their  deep-toned 

buzz  are  the  more  familiar  characters 

which  distinguish  them.      Over   fifty  species  of  bumblebees  occur  in  this 

countr)';   they  differ  in  size  and  in  the  arrangement  and  relative  amounts 


clover-blossom, 
life;    natural  size.) 


Fig.  723. — Worker  (A)  and  queen  (B) 
bumblebees,  Bombus  sp.  (After  Jordan 
and  Kellogg;   natural  size.) 


Wasps,  Bees,  and  Ants 


519 


of  the  black  and  yellow  markings  (PI.  XII,  Figs.  5  and  10).     A  common  eastern 

species  is  B.  jerviotus  (the  "  boiling  bumblebee"  is  good!),  which  has  the  body 

of  the  workers  almost  all  yellow  above,  only  a  narrow  median  band  across 

the  thorax  and  the  tip  of  the  abdomen  being  black;  B.  afjinis  has  (workers) 

the  base  of  the  abdomen,  its  posterior  half,  and  a  median  band  across  the 

thorax    black,  the  rest  yellow;     B. 

terricola  has  the  anterior  half  of  the 

thorax,  a  band  across   the   posterior 

third  of  the  abdomen,  and  another 

one  on  the  next  to  the  last  segment 

yellow,  the   rest   black;     B.   calijor- 

nicus,  the  most  abundant   species  in 

California,  has  the   anterior  half   of 

thorax    and    a    single   narrow   band 

near    tip    of    abdomen   yellow;     B. 

edwardsii,  another   species   common 

on  the  Pacific  coast,  has  a*  median 

band  across  the  thorax  and  a  broad 

anterior  one  across  the  abdomen  and 

the  very  tip  of  the  abdomen  black, 

the  rest  yellow. 

The  strange  case  of  the  guest 
bumblebee,  species  of  the  genus 
Psithyrus  (PI.  XII,  Fig.  4),  is  almost 
sure  to  come  to  the  attention  of  any 
observer  of  bumblebee-nests.  In  all 
general  characters  and  total  seeming 
truly  bumblebee-like,  found  always 
in  and  about  bumblebee-nests,  these 
insidious  guests,  cleverly  living  at  the 
bountiful  table  of  their  host,  present 
to  us  an  interesting  problem  touching 
their  deceptively  Bombus-like.  make- 
up. Are  they  really  bumblebees,  that  is,  bees  directly  descended  from 
bumblebee  stock,  which  have  become  degenerate  and  adopted  a  parasitic 
life,  or  are  they  bees  of  another  stock,  which,  for  the  sake  of  successfully 
deceiving  the  bumblebees  and  thus  gaining  access  to  their  nests,  have 
gradually  acquired  (through  long  selection)  the  bumblebee  dress  and  gen- 
eral appearance?  The  former  supposition  is  the  more  probable.  They 
are  like  bumblebees  in  so  many  structural  details  unnecessary  for  such 
deception  that  they  must  be  looked  on  as  a  degenerate  offshoot  from  the 
Bombidae.     Having  given  up  the  gathering  and  carrying  of  pollen,  their  tarsi 


Fig.  724. — Nest  of  bumblebee,  Bombtis  sp., 
showing  opening  at  surface  of  ground  and 
brood-cells  in  cavity  underneath.  (Adapted 
from  McCook.) 


::20 


Saw-flies,  Gall-flies,  Ichneumons, 


are  no  longer  provided  with  a  pollen-basket  (concave  smooth  surface 
bounded  by  lines  of  long  stiff  incurving  hairs)  and  by  the  absence  of 
this  arrangement  they  may  always  be  distinguished  from  the  true  bumble- 
bees. There  is  no  working  caste,  infertile  female  workers,  with  these 
Psithyridae,  each  species  being  represented  by  males  and  females  only. 

At  the  head  of  this  line  of  speciahzation  among  the  bees,  that  is,  the 
development  of  the  communistic  tendency,  stand  the  two  genera  of  honey- 
bees, Melipona  and  Apis.     The  numerous  species  of  Melipona  are  restricted 


Fig. 


725. — Comb  of  the  tiny  East  Indian  honey-bee,  Apis  florea. 
(After  Benton;    one-third  natural  size.) 


to  tropical  regions;  some  are  very  small,  the  so-called  "mosquito-bees,"  and 
in  all  the  sting  is  blunted  and  apparently  never  used  as  a  weapon.  The  life- 
history  of  no  one  of  the  species  has  been  fully  made  out,  and  there  is  some 
doubt  as  to  whether  each  community — some  of  the  nests  are  known  to  include 
an  enormous  number  of  individuals — has  but  a  single  queen — that  is,  single 
egg-laying  female — or  not.  Of  the  other  genus.  Apis,  there  are  but  few 
species,  the  best  known  being  the  common  hive-bee,  A.  mellifica,  which 
extends  naturally  over  all  the  northern  half  of  the  Old  World  and  from  there 
has  been  introduced  into  nearly  all  the  countries  of  the  globe.  In  its  long 
domestication  several  varieties  or  races  have  been  created  by  artificial  selec- 
tion, the  more  famihar  ones  being  the  German  or  black  race,  the  Italian 
or  amber  race,  and  the  Carniolan  or  striped  race. 


Wasps,  Bees,  and  Ants 


521 


A  community  of  the  hive-bee,  which  may  Hve,  of  course,  not  in  a  hive  at 
all,  but  in  a  hollow  tree,  as  undoubtedly  was  the  habit  of  the  species  in  wild 
state  (the  "bee-trees"  of  America,  however,  are  inhabited  by  bee  colonies 
which  have  swarmed  away  from  domesticated  ones  and  are  only  wild  by 
virtue  of  escaping  from  the  slave-yards  of  their  human 
masters),  consists  normally  of  about  10,000  (winter)  to 
50,000  (summer)  individuals,  of  which  one  is  a  fertile  fe- 
male,  the   queen;    a   few   score   to   several    hundred   are 


Fig.  726.  Fig.  727. 

Fig.  726. — The  honey-bee,  Apis  mellifica.    A,  queen;   B,  drone;   C,  worker.     (Natural 

size.) 
Fig.  727. — Hind  leg  of  worker  honey-bee,  Apis  mellifica,  showing  pollen-basket.     (Much 

enlarged.) 

males,  the  drones;  and  the  rest  are  infertile  females,  the  workers.     These 
three  kinds  of  individuals  are  readily  distinguishable  by  structural  charac- 


Fig.  728. — Ovaries  of  queen  {A)  and  worker  (B)  honey-bee,  Apis  mellifica.  et,  egg- 
tubes;  sp,  spermatheca;  pg,  poison-gland;  ps,  poison-sac.  (After  Leuckart;  much 
enlarged.) 

ters.     The  queen  (Fig.  726)  has  a  slender  abdomen  one-half  longer  than  that 
of  a  worker,  she  has  no  wax-plates  on  the  under  side  of  the  abdominal  seg- 


522 


Saw-flies,  Gall-flies,  Ichneumons, 


ments,  and  no  transverse  series  of  comb-like  hairs,  the  planta  (Fig.  734),  on 
the  under  side  of  the  broad  first  tarsal  segment  of  the  hind  feet,  and  no  pollen- 
basket  (Fig.  727)  on  the  outer  surface  of  the  hind  tibia.  The  drones,  males, 
(Fig.  726),  have  a  heavy  broad  body  excessively  hairy  on  the  thorax,  and 
lack  pollen-basket,  planta,  w^ax-plates,  and  other  special  structures  of  the 
vi^orkers.  The  workers  are  smaller  than  queen  or  drones,  and  possess  cer- 
tain special  structures  or  body  modifications  to  enable  them  to  perform  cer- 
tain special  functions  connected  with  their  performance  of  the  various  indus- 
tries characteristic  of  the  species.  These  special  structures  will  be  described 
in  some  detail  later  when  the  various  special  industries  are  particularly  con- 
sidered. In  internal  organization  the  workers  differ  from  the  queen  in 
having  the  ovaries  rudimentary  (Fig.  728),  so  that  only  in  exceptional  cases 
can  a  worker  produce  fertile  eggs. 

In  functions  the  three  castes  differ  as  they  do  in  the  social  wasps  and 
the  bumblebees,  only  more  constantly;  that  is,  the  queen  lays  the  eggs,  never, 
as  with  Bombus  and  the  Vespids,  doing  any  food-gathering  or  nest-building; 


Fig.  729. — Honey-bees  gathering  pollen  and  nectar.     (From  life.) 

the  males  act  simply  as  consorts  for  the  queen,  which  means  that  only  one 
of  every  thousand,  perhaps,  performs  any  necessary  function  at  all  in  the 
communal  economy;  the  workers  build  brood-  and  food-cells,  gather,  pre- 
pare, and  store  food,  feed  and  otherwise  care  for  the  young,  repair,  clean, 
ventilate,  and  warm  the  hive,  guard  the  entrance  and  repel  invaders,  feed 
the  queen,  control  the  production  of  new  queens,  and  distribute  the  species, 
founding  new  communities,  by  swarming. 

The  hfe-history  of  a  community  is  as  follows:  A  "swarm"  (how  and 
when  a  swarm  is  formed  will  be  explained  later),  consisting  of  a  queen  (fertile- 
female)  and  a  number  of  workers  (from  two  to  twenty  thousand  or  more)^ 


Wasps,  Bees,  and  Ants 


523 


issues  from  a  community  nest  (hive,  hollow  tree,  or  elsewhere)  and  finds,, 
through  the  efforts  of  a  few  of  the  workers,  a  place  for  a  new  nest  (in  another 
sheltered  hollow  place,  usually,  through  the  intervention  of  the  bee-keeper, 
another  hive).  Taking  possession  of  this  new  nesting-place,  the  workers 
immediately  begin  to  secrete  wax  (method  described  later)  and  to  build 
"comb,"  i.e.,  double-tiered  layers  of  waxen  cells,  usually  as  "curtains" 
or  plates  hanging  down  from  the  ceiling  of  the  nest  (the  bee-keepers  supply 
artificially  made  "foundations"  or  beginnings  of  these  curtains  in  vertical 
frames  set  parallel  and  lengthwise  of  the  hive,  so  that  the  combs  will  be 
built  symmetrically  and  conveniently  for  the  bee-keeper's  handling).  In 
many  of  these  cells  the  queen,  which  has  received  the  fertilizing  sperm-cells 


Fig.  730. — Brood-cells  from  honey-bee  comb  showing  different  stages  in  the  metamor- 
phosis of  the  honey-bee;  worker  brood  at  top  and  three  queen-cells  below;  begin- 
ning at  right  end  of  upper  row  of  cells  and  going  to  left,  note  egg,  young  larva,  old 
larva,  pupa,  and  adult  ready  to  issue;  of  the  large  curving  queen-cells,  two  are  cut 
open  to  show  larva  within,     (.\fter  Benton;    natural  size.) 


from  a  male  during  a  mating  flight  high  in  the  air,  lays  fertilized  eggs,  one 
at  the  very  bottom  of  each  cell.  In  other  cells,  pollen  and  honey  brought 
by  workers  (the  honey  brought  as  flower-nectar  and  made  from  this,  as 
explained  later)  are  stored  for  food.  In  three  days  the  eggs  hatch,  the  tiny 
larvai  being  footless,  white,  soft-bodied,  helpless  grubs.  They  are  fed  at 
first  exclusively  with  "bee-jelly,"  a  highly  nutritious,  predigested  substance 
elaborated  in  the  bodies  of  the  nurse  workers  and  regurgitated  by  them 
into  the  mouths  of  the  larvae.  After  a  couple  of  days  of  feeding  with  this 
substance,  the  larv£e  are  fed,  in  addition  to  bee-jelly,  pollen  and  honey  taken 
by  the  nurses  from  the  cells  stored  with  these  food-substances.  After  three 
days  of  this  mixed  feeding,  the  larvae  having  grown  so  as  to  fill  half  or  two- 
thirds  of  the  cell,  lying  curled  in  it  (Fig.  730),  a  small  mass  of  mixed  pollen 


524  Saw-flies,  Gall-flies,  Ichneumons, 

and  honey  is  put  into  each  cell,  which  is  then  capped,  i.e.,  sealed  over  with 
a  thin  layer  of  wax.  The  larva  feeds  itself  for  a  day  or  so  longer  on  the 
"bee-bread"  and  then  pupates  in  the  cell.  The  quiescent  non-feeding 
pupal  stage  lasts  for  thirteen  days,  when  the  fully  developed  bee  issues  from 
the  thin  pupal  cuticle,  gnaws  away  the  wax  cap  and  emerges  from  the  cell. 
For  from  ten  days  to  two  weeks  the  bee  does  not  leave  the  hive;  it  busies 
itself  with  indoor  work,  particularly  nurse  work,  the  feeding  and  care  of 
the  young.  Then  it  takes  its  place  with  the  fully  competent  bees,  makes 
foraging  expeditions  or  undertakes  capably  any  other  of  the  varied  indus- 
tries of  the  worker  caste. 

After  numerous  workers  have  been  added  to  the  community,  egg-laying 
by  the  queen  going  on  constantly  day  after  day,  so  that  the  young  come  to 
maturity,  not  in  broods,  but  consecutively,  day  after  day,  certain  hexagonal 
cells  of  plainly  larger  diameter  are  made  by  the  comb-building  workers,  and 
in  these  the  queen  lays  unfertilized  eggs.  This  extraordinary  capacity  for 
producing  either  fertilized  or  unfertilized  eggs,  as  demanded,  depends  upon 
the  queen's  control  of  the  male  fertilizing  cells  held  in  the  spermatheca. 
This  reservoir  of  fertilizing  cells  can  be  kept  open  as  eggs  pass  down  the  ovi- 
duct and  by  it  on  their  way  out  of  the  body,  thus  allowing  the  spermatozoids 
to  swim  out,  penetrate  (through  the  micropyle  in  the  egg-envelopes)  and 
fertilize  the  eggs,  or  it  may  be  kept  closed,  preventing  the  issuance  of  the 
spermatozoids  and,  consequently,  fertilization.  From  the  unfertilized  eggs 
laid  in  the  larger  cells  hatch  larvae  which  are  fed  and  cared  for  in  the  same 
way  as  the  worker  larvae,  but  which  require  six  days  for  full  growth,  the 
pupal  stage  lasting  fifteen  days.  When  finally  the  fully  developed  bees 
issue  from  these  cells  it  will  be  found  that  all  are  males  (drones).  This 
parthenogenetic  production  of  drones,  discovered  about  1840  by  Dzierzon, 
and  long  accepted  as  proved,  was  recently  questioned  by  Dickel  and  one 
or  two  other  naturalists  and  was  therefore  reinvestigated  by  Petrunkewitsch 
and  others,  with  the  result  of  confirming,  on  new  evidence  and  by  new 
methods  of  investigation,  the  declarations  of  the  discoverer  of  the  fact. 

If,  now,  our  community  has  increased  so  largely  in  numbers  that  its 
quarters  begin  to  be  insufficient  for  further  expansion,  certain  excited  groups 
of  workers  will  be  seen  tearing  down  certain  cells  and  replacing  them  by  a  new 
giant  cell  which  is  usually  built  up  around  one  of  the  fertilized  eggs  laid  in  a 
small  hexagonal  cell.  The  egg  hatches  before  the  cell  is  finished,  and  the 
larva  lies  in  the  large  open  cavity  of  the  growing  cell,  on  which  numerous 
nurses  are  in  constant  attendance.  Often  several  of  these  unusual  giant 
cells  may  be  built  at  one  time.  The  larva  which  hatches  from  the  fertilized 
egg  in  one  of  these  cells  is  fed  the  nutritious  bee-jelly  through  all  of  its  life, 
little  or  no  pollen  or  honey  being  given  it.  When  the  larva  is  five  days 
old  a  quantity  of  the  milky  semi-fluid  jelly  is  put  into  the  cell,  which  is  then 


Wasps,  Bees,  and  Ants  525 

capped,  the  opening  being  at  the  bottom  of  the  hanging,  nut-shaped  cell, 
and  in  only  seven  days  more  the  fully  developed  bee  issues.  This  bee  is  a 
queen.  Very  rarely  a  worker  and  not  a  queen  issues  from  a  queen-cell. 
That  is,  a  larva  hatching  from  a  fertilized  egg  laid  by  the  queen  in  a  small 
hexagonal  cell,  if  fed  bee-jelly  for  two  or  three  days  and  then  pollen  and  honey, 
will  develop  into  a  worker;  that  larva  from  the  same  egg,  if  fed  bee- jelly 
all  its  life,  and  reared  in  a  large  roomy  cell,  will  develop  into  a  queen.  The 
difference  between  a  queen  honey-bee  and  a  worker  honey-bee,  both  struc- 
tural and  physiological,  are,  as  already  pointed  out,  conspicuous.  The 
influence  of  a  varying  food-supply  is  something  mysteriously  potent,  and 
this  case  of  the  queen  bee  gives  great  comfort  to  those  biologists  who  believe 
that  the  external  or  extrinsic  factors  surrounding  an  animal  during  develop- 
ment have  much  influence  in  determining  its  outcome. 

As  there  is  by  immemorial  honey-bee  tradition  but  one  queen  in  a  com- 
munity at  one  time,  when  new  queens  issue  from  the  great  cells  something 
has  to  happen.  This  may  be  one  of  three  things:  either  the  old  and 
new  queens  battle  to  death,  and  it  is  believed  that  in  such  battles  only  does 
a  queen  bee  ever  use  her  sting,  or  the  workers  interfere  and  kill  either  the 
old  or  new  queen  by  "balling"  her  (gathering  in  a  tight  suffocating  mass 
about  her),  or  either  old  (usually  old)  or  new  queen  leaves  the  hive  with  a 
swarm,  and  a  new  community  is  founded.  If  several  new  queens  are  to 
issue,  the  workers  usually,  by  thickening  from  the  outside  the  walls  of  one 
or  more  of  the  cells,  compel  the  issuing  to  be  successive  and  not  simultaneous. 
This  results  in  a  series  of  royal  battles,  or  a  series  of  swarmings,  or  a  com- 
bination of  the  two.  A  queen  ready  to  issue  from  a  cell  makes  a  curious 
piping  audible  some  yards  from  the  hive,  which  is  answered  by  a  louder 
piping,  a  trumpeting,  from  the  old  queen.  At  these  times  there  is  great 
excitement  in  the  hive,  as  indeed  there  is  during  all  of  the  queen-raising 
season. 

The  swarming  out,  it  is  apparent,  does  not  break  up  the  old  community; 
in  fact  only  accident,  or  the  successful  attacks  of  such  insidious  enemies 
as  the  bee-moth,  and  various  contagious  diseases,  break  up  the  parent 
colony.  In  this  respect  is  to  be  noted  an  important  difference  between 
the  other  social  bees  and  wasps  with  their  communities  annually  destroyed 
and  refounded,  and  the  honey-bee  with  its  persistent  one.  Of  course  workers 
die  and  so  do  drones  and  queens.  The  tireless  workers  which  hatch  and 
labor  in  the  spring  and  summer  months  rarely  live  more  than  six  or  eight 
weeks,  while  the  workers  born  in  the  late  autumn  and  remaining  quietly 
in  the  shelter  of  the  hive  through  the  winter  live  for  several  months.  Queens 
live,  usually,  if  no  accident  befalls,  two  or  three  years;  an  age  of  four  or 
five  years  is  occasionally  attained.  Most  of  the  drones  in  each  community 
either  die  naturally  before  winter  comes  or  are  killed  by  the  workers.     Feeble 


^26  Saw-flies,  Gall-flies,  Ichneumons, 

workers  and  larvae  and  pupaj  are  also  sometimes  killed  just  before  winter, 
if  the  food-stores  which  are  to  carry  the  community  through  the  long  flower- 
less  season  are  for  any  reason  not  likely  to  prove  sufficient  for  so  large  a  num- 
ber of  individuals.  In  all  these  matters,  that  is,  the  making  of  queens  and 
when,-  the  swarming  out  and  when,  and  the  reduction  of  the  community  to 
safe  winter  numbers,  the  decision  is  made  by  the  workers  and  not  the  queen. 
The  queen  is  no  ruler;  she  is  the  mother,  or,  better,  simply  the  egg-layer 
for  the  whole  community. 

The  drones,  we  have  seen,  have  one  particular  function  to  perform  in 
the  community  life,  the  queen  another  single  particular  function;  but  the 
workers  have  numerous  varied  performances  to  achieve  if  the  community 
shall  live  successfully.  It  might  be  expected,  from  analogous  conditions 
elsewhere  existing  in  animal  life,  that  with  the  di\dsion  of  labor  in  the  honey- 
bee economy  there  should  be  a  corresponding  differentiation  of  structure 
or  polymorphism  inside  the  species.  This  polymorphism  or  existence  of 
structurally  different  kinds  of  individuals  occurs  in  bees  only  to  the  extent 
already  pointed  out;  there  are  three  kinds  of  individuals:  the  queens,  with 
a  special  function,  the  drones,  with  a  single  special  function,  and  the  workers, 
each  capable  of  performing,  and,  for  the  time  of  the  performance,  doing  it 
exclusively,  any  of  the  varied  industries  necessary  to  the  community  life. 
All  worker  honey-bees  are  ahke,  each  possessing  all  the  special  structural 
specializations,  as  pollen-basket,  wax-plates,  wax-shears,  trowel-hke  jaws, 
etc.,  which  have  been  developed  for  the  special  performance  of  particular 
industries.  In  some  other  communal  insects  a  differentiation  or  pohTnor- 
phism  among  the  workers  exists;  many  ant  species  have  two  or  even  three 
kinds  of  workers,  the  termites  have  soldiers  as  well  as  workers,  etc.  I  pur- 
pose now  to  describe  briefly  each  of  the  principal  special  industries  achieved 
by  the  workers,  at  the  same  time  describing  the  structural  speciaHzation 
connected  with  each  of  these  industries. 

The  wax  produced  by  the  workers  is  a  secretion  which  issues  as  a  liquid, 
soon  hardening,  from  pairs  of  thin  five-sided  plates,  one  pair  on  the  ventral 
surface  of  each  of  the  last  four  abdominal  segments  (Fig.  731).  It  is  secreted 
by  modified  cells  of  the  skin  lying  under  the  chitinized  cuticle  of  the  plates, 
and  oozes  out  through  fine  pores  in  the  plates.  To  produce  it  certain  work- 
ers eat  a  large  amount  of  honey,  then  massing  together  form  a  curtain  or 
festoon  hanging  down  from  the  ceiling  of  the  hive  or  frame,  and  increase 
the  temperature  of  their  bodies  by  some  strong  internal  exertion;  after  the 
lapse  of  several  hours,  sometimes  indeed  two  or  three  days,  fine,  thin,  glisten- 
ing, nearly  transparent  scales  of  wax  appear  on  the  "wax-plates."  These 
wax-scales  continue  to  increase  in  area  and  soon  project  beyond  the  margin 
of  the  segment,  when  they  either  fall  off  or  are  plucked  off  by  other  workers 
or  by  the  wax-producing  worker  itself.     They  are  then  taken  in  the  mouth, 


Wasps,  Bees,  and  Ants 


527 


sometimes  chewed  and  mixed  with  some  saHva,  and  carried  to  the  seat  of 
the  comb-building  operation.  Here  the  wax  is  pressed  against  the  frame  roof 
(or  artificial  foundation)  and  by  means  of  the  trowel-like  mandibles  moulded 
into  the  familiar  hexagonal  cells;    each  comb  being  composed  of  a  double 


Fig.  731, 


Fig.  732. 


Fig.  731. — Ventral  aspect  of  abdomen  of  worker  honey-bee,  showing  wax-plates.     (Three 

times  natural  size.) 
Fig.  732. — Wax-plate  from  ventral  aspect  of  abdomen  of  honey-bee.     (Much  enlarged.) 

layer  of  these  cells,  a  common  partition  serving  as  base  or  bottom  of  each 
tier.  Although  most  bee  books  speak  rather  gUbly  of  the  comb-building 
operations,  it  is  still  undetermined  whether  the  wax-producers  leave  the  cur- 
tain and  carry  their  own  wax  to  the  new  comb  and  help  mould  it,  or  whether 


Fig.  733. — Honey-bees  building  comb.     (After  Benton.) 

the  scales  are  taken  away  by  other  (building)  workers,  or  whether  they  are 
nipped  off  with  the  wax-shears  (Fig.  734)  of  the  hind  legs,  and  if  so,  whether 
by  the  wax-maker  or  a  helper  or  builder,  or  whether  they  fall  off  to  the  bot- 


528 


Saw-flies,  Gall-flies,  Ichneumons, 


torn  of  the  hive  and  are  there  gathered  up  by  helpers  or  builders,  or  whether 
all  or  most  of  these  various  performances  occur — which  from  my  own  obser- 
vations and  those  of  my  students  seems  true.  In  building  cells  for  storing 
honey,  new  wax  is  almost  exclusively  used;  for  brood-cells  old  wax  and 
wax  mixed  with  pollen  may  be  used.  Any  comb  or 
part  of  a  comb  not  needed  is  torn  down  and  the  wax 
used  to  build  other  comb-  or  cap-cells. 

The  seeking  and  collection  of  pollen  and  honey 
is  not  undertaken  by  a  bee  until  from  ten  to  fifteen 
days  after  its  emergence  from  the  pupal  cuticle,  these 
first  days  being  spent  in  the  hive  at  nurse  or  other 
indoor  work.  Then  short  orienting  flights  begin  to 
be  made,  and  soon  the  long-distance  flights  (a  mile 
or  more  sometimes),  which  are  often  necessary  for 
successful  foraging,  are  undertaken.  The  pollen  is 
taken  up  or  brushed  off  from  the  ripe  anthers  of  the 
flowers  with  the  mouth-parts,  fore  legs,  or  ventral 
body-wall,  the  pollen-grains  being  readily  entangled 
in  the  numerous  branching  hairs,  and  then,  by 
clever  manipulation  of  the  fore,  middle,  and  hind 
legs  aided  by  special  pollen-brushes  (plantae)  (Fig. 
734)  on  the  inner  side  of  the  front  tarsal  segments  of 
the  hind  feet,  transferred  to  and  packed  into  the 
pollen-baskets  (Fig.  734),  one  in  the  outer  face  of 
each  hind  tibia.  A  forager  loaded  with  pollen  re- 
turns to  the  hive,  and,  seeking  an  empty  cell  near 
the  brood-cells,  stands  over  and  with  his  hind  legs 
partly  in  it  and  thrusts  off  the  two  masses,  with  the 
aid  of  the  middle  legs  (the  spurs  of  the  middle  tibiae 
being  apparently  often  used  as  pries).  This  pollen 
is  tamped  down  in  the  cell  by  inside  workers  and 
receives  no  further  manipulation. 

The  "honey"  which  is  collected  by  the  foragers 
is  not  yet  bee-honey,  but  is  nectar  of  flowers,  too  watery  and  too  likely  not 
to  "keep"  to  be  stored  in  the  ceUs  without  further  treatment.  It  is  sucked 
and  lapped  up  by  the  compUcated  elongate  flexible  mouth-proboscis,  swal- 
lowed into  the  fore  stomach  or  honey-sac  (Fig.  735),  and  carried  in  this  to 
the  hive  Bees  have  been  seen  to  exude  drops  of  water  on  their  return 
flight  when  honey-laden,  and  it  is  possible  that  it  comes  from  the  nectar  in  the 
honey-stomach.  At  any  rate,  some  ten  or  twelve  per  cent,  of  the  water  con- 
tent of  the  nectar  has  to  be  evaporated  before  this  nectar  becomes  honey. 
When   the    foraging   worker    with    honey-sac   full    returns    to   the   hive    it 


Fig.  734. — First  tarsal 
segment  of  hind  legs, 
front  and  back  view, 
of  honey  -  bee.  i, 
drone;  2,  worker;  and 
3,  queen,  a,  distal  tip 
of  tibia;  b,  first  tarsal 
segment;  c,  proximal 
end  of  second  tarsal 
segment.  (After 

Sharp;       much      en- 
larged.) 


Wasps,  Bees,  and  Ants 


529 


regurgitates  its  nectar  either  into  the  mouth  of  another  bee  or  into  a  clean  (new 
wax)  cell,  usually  near  the  margin  of  the  comb.  At  the  bottom  of  the  honey- 
sac  is  the  so-called  stomach-mouth,  a  little  pea-like  protuberance  with  two 
cross-sHts,  making  four  hps.  These  lips  can  be  opened  or  closed  voluntarily; 
if  the  bee  drinking  nectar  wishes  to  bring  it  back  to  the  hive  to  store  it,  she 
keeps  them  closed,  thus  making  a  sac  of  the  honey- 
stomach,  open  only  through  the  mouth ;  whenever  she 
wishes  to  feed  herself  she  opens  them,  thus  allowing 
the  honey  or  pollen  to  pass  on  into  the  true  or  digest- 
ing stomach.  This  arrangement  also  permits  of  the 
regurgitation  of  the  bee-jelly  or  bee-milk  (fed  the 
larvae  by  the  nurse  workers),  which  is  believed  to  be 
prepared  in  the  true  stomach,  pressed  past  the  lips 
forward  into  the  honey-stomach  and  on  through  the 
oesophagus  into  the  mouth. 

When  the  nectar  is  put  into  the  honey-cells  it  has 
still  to  have  much  water  evaporated  from  it.  To 
accomplish  this  an  effective  system  of  ventilation 
(see  p.  530)  is  now  set  up  in  the  hive,  so  that  air- 
currents  pass  constantly  over  the  open  nectar-con- 
taining cells;  moreover,  by  the  very  vigor  of  this 
activity  on  the  part  of  the  bees  the  temperature  of 
their  bodies  is  raised ;  by  radiation  of  heat  from  the 
bodies  the  temperature  in  the  hive  is  sensibly  in- 
creased, and  the  currents  of  warm  air  soon  carry  off  the  excess  water.  To 
make  the  honey  "keep,"  that  is,  to  make  it  antiseptic,  formic  acid  is  added 
to  it,  probably  from  glands  in  the  head  whose  secretions  distinctly  show  its 
presence.  It  is  just  possible  that  the  formic  acid  is  suppHed  by  the  poison- 
sacs,  the  poison  introduced  by  the  bee's  sting  being  largely  composed  of 
formic  acid.  But  it  is  much  more  probable  that  at  the  time  of  the  regurgi- 
tation of  the  nectar  from  the  honey-stomach  through  the  mouth  the  formic- 
acid  secretions  from  the  head-glands  are  mixed  with  it. 

Nectar  for  honey-making  is  obtained  by  bees  from  a  great  many  different 
plants,  but  that  from  some  makes  honey  better,  to  our  taste,  than  that  from 
others.  Among  the  most  important  producers  of  the  best  honey  in  the  east  and 
north  are  white  clover,  basswood,  buckwheat,  and  the  fruit-trees  and  small 
fruits;  in  the  middle  states  are  the  tulip-tree,  sorrel- tree,  sweet  clover,  and 
alfalfa;  in  the  south  are  the  mangrove,  cabbage-  and  saw-palmettos,  and 
sorrel-tree;  while  in  the  west  are  alfalfa  and  white  sage.  The  best  and 
most  of  the  Cahfornia  honey  is  from  the  wild  white  sage. 

Besides  pollen  and  nectar,  two  other  substances  are  collected  and  brought 
to  the  hive  by  the  foraging  workers.      At   some   seasons  of  the  year  when 


Fig.  735 .  —  Alimentary 
canal  of  worker  honey- 
bee showing  (hs) 
honey-sac  lying  di- 
rectly behind  {(e) 
oesophagus.  (Much 
enlarged.) 


530  Saw-flies,  Gall-flies,  Ichneumons, 

many  larvae  are  being  reared,  and  the  supply  of  water  derived  by  con- 
densation of  the  moisture  in  the  warm  hive  atmosphere  as  this  air  strikes 
the  cooler  hive-walls  is  insufficient,  the  workers  drink  up  dew  from  leaves, 
or  water  from  puddles,  which  they  hold  in  the  honey-sac  and  bring  to  the 
hive,  regurgitating  it  into  the  thirsty  larval  mouths.  For  the  filHng  in  of 
crevices,  the  stopping  up  of  holes,  the  fastening  together  of  loose  parts,  etc., 
the  bees  use  a  substance  called  propolis,  which  is  simply  the  resinous  exuda- 
tions of  various  plants.  This  propohs  is  collected  and  packed  into  the  pol- 
len-baskets as  pollen  is  and  brought  in  by  the  foragers.  Some  of  my  bees, 
needing  propolis,  discovered  a  house  just  in  course  of  painting,  and  made 
a  gallant  though  hopeless  struggle  to  bring  in  all  the  fresh  paint  as  fast  as 
it  was  put  on  by  the  painters!  This  house  must  have  seemed  a  remarkable 
sort  of  propoKs-producing  plant!  Propolis  is  not  packed  in  cells,  but  is 
used  as  soon  as  brought  in,  the  trowel-mandibles  being  the  instruments  used 
in  putting  and  moulding  it  in  the  needed  place. 

Of  the  indoors  work  there  is  much  besides  those  industries  already  referred 
to,  namely,  wax-making,  comb-building,  honey-making,  crevice-chinking. 
Because  the  queen  and  nurses  (bees  less  than  two  weeks  old)  do  not  leave 
the  hive  their  excreta  are  voided  within  doors;  there  are  also  bits  of  old,  dirty 
wax,  occasional  dead  bees,  and  various  other  waste  substances  constantly 
accumulating  in  the  hive.  Or,  rather,  this  detritus  would  accumulate  if 
the  workers  were  not  always  keenly  careful  to  carry  out  all  such  stuff;  the 
hive  is  constantly  being  cleaned,  and  is  on  any  day  in  the  week  a  model  of 
good  housekeeping. 

Besides  keeping  the  hive  clean  the  workers  must  keep  it  ventilated,  that 
is,  clean  of  atmosphere  as  well  as  clean  of  floor  and  wall.  This  is  done  by 
setting  up  air-currents  through  the  hive  which  carry  out  constantly  the  viti- 
ated air  and  thus  compel  fresh  air  to  enter.  Always  near  the  exit  and  scat- 
tered through  the  hive,  especially  along  its  floor,  may  be  seen  bees  standing 
with  head  down  and  body  diagonally  up  and  wings  steadily  vibrating  with 
great  rapidity.  These  are  the  ventilating  agents,  and  they  have  an  exhaust- 
ing and  tedious  work. 

About  the  entrance  may  be  also  always  seen  bees  which  seem  neither  to  be 
leaving  the  hive  nor  entering  it,  but  which  move  about  constantly  and  meet  and 
touch  antennae  with  all  incomers.  These  are  the  warders  of  the  gate.  There 
are  never  wanting  enemies  of  the  industrious,  well-stocked  honey-bee  com- 
munity, whose  entrance  into  the  hive  must  be  vigorously  guarded  against. 
Yellow -jackets  hover  tentatively  around  the  opening;  they  are  arrant  rob- 
bers and  are  ready  to  take  any  chance  to  get  at  the  full  honey-cells.  But 
more  dangerous  because  of  the  habit  of  attacking  en  masse  are  honey-bees 
of  other  hives.  Not  infrequently  a  desperate  foray  by  hundreds  of  other 
bees  will  be  made  into  a  hive,  especially  a  weak  one,  and  a  pitched  battle 


Wasps,  Bees,  and  Ants 


531 


will  occur  in  and  about  the  entrance  and  inside  the  hive  itself,  resulting  in 
the  death  of  hundreds,  even  thousands,  of  bees.  More  insidious  and  even 
more  dangerous  are  the  stealthy  invasions  of  a  small  dusty-winged  moth, 
the  bee-moth  (Galleria  mellonella),  which,  slipping  in  at  night  unobserved, 
lays  its  eggs  in  cracks;  the  larvae  which  hatch  from  the  eggs  feed  on  the 
wax  of  the  combs,  and  as  they  spin  a  silken  net  over  them  wherever  they  go, 
the  presence  of  many  such  works  great  injury  both  in  the  actual  destruction 
of  comb  and  in  the  felting  and  cobwebbing  of  the  interior  of  the  hive  with 
the  tough  silken  netting.  Other  still  more  insidious  enemies  there  are,  as 
the  minute  bee-Hce  (Braula),  which  attach  themselves  to  the  bees  and  suck 
out  their  body- juices,  and  the  invisible  bacterial  germs  of  foul-brood  and 
other  characteristic  bee  diseases.  But  all  these  are  beyond  the  sensitiveness 
of  the  guards  to  recognize,  and  for  the  successful  fighting  of  them  the  aid 
of  the  bee-keeper  is  necessary. 

The  feeding  and  care  of  the  young  bees,  the  larvae,  have  already  been 
partly  described  in  the  account  of  the  life-history  of  the  different  kinds  of 


Fig.  736. — An  ordinary  beehive  made  into  an  observation-hive  by  inserting  glass  panes 
in  sides  and  putting  a  glass  sheet  under  the  wooden  cover.  (Drawn  from  hive  in 
the   author's  laboratory.) 


individuals  in  the  community  and  cannot  be  further  referred  to  in  this  brief 
history  of  the  honey-bees'  domestic  economy.  Of  course  only  the  more  con- 
spicuous features  in  this  economy  have  been  described  at  all;  a  host  of  inter- 
esting details  cannot  even  be  mentioned.  But  enough  has  been  said,  surely, 
to  indicate  the  fascinating  field  for  observation  afforded  by  a  honey-bee  com- 
munity.    If  such  a  community  be  kept  in  an  observation-hive  and  this  hive 


s?>^ 


Saw-flies,  Gall-flies,  Ichneumons, 


be  placed  conveniently  near  the  house,  or,  better,  inside  one's  room,  it  will 
prove  a  never-failing  source  of  interest  and  pleasure. 

Perhaps  it  had  better  be  explained  how  an  observation-hive  can  be  kept 
in  one's  room  without  interfering  with  coincident  human  occupancy.  The 
observation-hive,  in  the  first  place,  may  be,  as  shown  in  Fig.  736,  simply  an 
ordinary  outdoors  hive  into  each  side  of  which  a  large  pane  of  glass  has 
been  let,  with  swinging  outer  wooden  doors,  one  on  each  side,  which,  when 
shut,  keep  the  hive  in  normal  darkness,  but  opened,  allow  "observing"  to 
go  on.  In  addition  to  the  side  glasses  a  loose  sheet  of  glass  is  inserted  just 
under  the  ordinary  "honey-board"  or  removable  top  of  the  hive.  Or  the 
observation-hive  may  be,  as  shown  in  Fig.  737,  a  special,  narrow,  two-frame 


Fig.  737. — An  observation -hive  holding  only  two  frames,  with  the  two  sides  wholly  of 
glass,  so  that  any  single  bee  can  be  continuously  watched.  (Drawn  from  hive  in 
author's  laboratory.) 

hive,  with  both  sides  wholly  composed  of  glass  held  in  the  narrow  wooden 
frame  which  forms  the  ends  and  the  top  and  bottom  of  the  hive.  A  black 
cloth  jacket  should  be  kept  on  the  hive  when  "  observing  "  is  not  going  on. 
In  such  a  hive,  which  will  obviously  hold  but  a  small  community  (one  of 
not  over  10,000  individuals)  any  single  bee  can  be  kept  continuously  under 


Wasps,  Bees,  and  Ants  533 

observation,  as  there  are  no  side-by-side  frames  between  which  it  can  crawl 
and  thus  be  hidden  from  view.  To  keep  either  of  such  hives  in  the  house  it 
is  only  necessary  to  substitute  for  a  pane  of  glass  in  a  window  a  thin  wooden 
pane  in  which  is  cut  a  narrow  horizontal  opening,  the  size  of  the  regular  hive- 
opening  (if  the  latter  is  too  broad  it  can  be  closed  for  a  few  inches  at  each 
end).  Or  a  narrow  board  strip  of  the  full  width  of  the  window  can  be  inserted 
so  that  the  lower  sash  of  the  window,  when  closed,  will  rest  on  this  strip. 
In  the  strip  cut  a  narrow  opening  of  the  width  or  less  of  the  hive-opening. 
Set  the  observation-hive  on  a  table  or  shelf  against  the  window  so  that  the 
hive-opening  corresponds  with  that  in  the  window-pane  or  window-strip. 
Or,  better,  place  it  six  or  seven  inches  from  the  window  and  connect  hive  and 
window-opening  by  a  shallow  broad  tunnel  of  wooden  bottom  and  sides  but 
glass  top.  Over  the  glass  top  of  this  tunnel  lay  a  sheet  of  black  cardboard, 
which  will  keep  the  tunnel  dark  normally,  but  which  can  be  simply  hfted 
off  whenever  it  is  desired  to  see  what  is  going  on  at  the  entrance.  Here  can 
be  seen  the  departure  of  the  foragers  and  their  arrival  with  pollen,  propoHs, 
or  honey,  the  alertness  of  the  guards,  the  repelling  of  robbers  and  enemies, 
the  killing  of  drones,  the  ventilating,  etc.,  etc.  Through  the  glass  sides  of 
the  hive  itself  can  be  seen  all  the  varied  indoors  businesses  in  their  very  under- 
taking; the  life-history  of  each  kind  of  individual  can  be  followed  in  detail; 
the  wax-making  and  comb-building,  the  storing  of  the  food-cells,  the  feeding 
of  the  young  by  the  nurses,  the  excitements,  the  joys,  and  the  discourage- 
ments, the  whole  course  of  life  in  this  microcosm. 

The  natural  questions  of  the  thoughtful  observers  of  honey-bee  life  touch- 
ing the  probable  origin  and  causal  factors  of  this  elaborate  train  of  behavior 
will  be  found,  not  answered,  to  be  sure,  but  discussed,  at  the  end  of  this  chap- 
ter. For  before  undertaking  any  consideration  of  the  much-discussed  prob- 
lem of  reflexes,  instincts,  and  intelligence  in  the  communal-living  insects, 
we  should  examine  the  life  and  ways  of  the  ants,  the  most  specialized  of  all 
the  social  animals. 

ANTS. 

Unlike  the  w^sps  and  bees,  the  two  other  great  groups  of  Hymenoptera 
that  contain  communal-hving  species,  the  ants  (superfamily  Formicina) 
include  no  solitary  species  at  all,  every  one  of  the  twenty-five  hundred  or 
more  known  ant  species  living  in  communities.  The  development  or  evolu- 
tion of  social  life  in  persistent  communities  is  accomplished  for  the  whole 
group;  no  connecting  or  gradatory  forms  living  in  annually  destroyed  com- 
munities (like  those  of  the  bumblebees  and  social  wasps)  or  in  simple  colonies 
of  gregarious  individuals  (like  Hahctus  and  other  mining-bees)  exist  to  con- 
nect the    ants  with  the  solitary  or  independent   life  common  to  the   great 


to^  Saw-flies,  Gall-flies,  Ichneumons, 

majority  of  insects.*  And  the  division  of  labor,  establishment  of  castes  or 
kinds  of  individuals,  and  marked  differentiation  of  structure  are  developed 
to  the  extreme  among  the  ants.  The  variety  of  habits  and  the  special  adap- 
tations to  different  conditions  are  also  represented  in  their  widest  range  and 
most  complex  stage  of  development  among  the  ants.  Obviously  the  ants 
are  at  the  head,  the  extreme  forefront  of  this  kind  of  specialization  in  insect 
life. 

No  insects  are  more  famihar.  They  hve  in  all  lands  and  regions;  they 
exist  in  enormous  numbers;  they  are  not  driven  away  by  the  changes  in 
primitive  nature  imposed  by  man's  occupancy  of  the  soil;  they  mine  and 
tunnel  his  fields  and  invade  his  dwelhngs.  And  many  things  which  man 
attempts  they  do  more  successfully  than  he  does,  and  may  be  his  teachers! 

But  few  other  insects  can  be  mistaken  for  ants  even  by  the  most  super- 
ficial observer;  the  wingless  Mutillid  wasps,  so-called  velvet  ants,  are  rather 
like  them  in  general  appearance,  and  the  smaller  termites,  or  white  ants, 
bear  just  a  shght  superficial  resemblance  to  true  ants,  especially  in  the  case 
of  the  sexual  individuals  with  their  long  narrow  wings.  But  ants  may  be 
at  once  definitely  distinguished  from  all  other  insects  by  the  readily  made 
out  structural  character  of  the  basal  segments  or  peduncle  of  the  abdomen. 
One  or  two  of  these  segments  are  expanded  dorsally  to  form  a  Httle  scale 
or  flat  button-like  knot — a  characteristic  exhibited  by  no  other  insects.  For 
the  rest,  ants  show  a  body  structure  like  that,  in  general,  of  the  wasps  and 
bees:  compact  and  well-distinguished  thorax  and  abdomen;  wings  (present 
only  in  males  and  fertile  females,  and  in  them  easily  removable)  with  a  few 
sparsely  branching  veins  and  few  cells;  the  mouth  furnished  with  strong 
biting-jaws,  which  in  most  species  can  be  used  without  the  opening  or  even 
the  moving  of  the  other  mouth-parts  (maxillae  and  lips);  antennae  slender, 
cyhndrical,  and  sharply  elbowed  at  the  end  of  the  rather  long  basal  segment; 
legs  long  and  strong  and  fitted  for  running,  and  the  body-wall  firm  and 
smooth.  Many  ants  have  a  stridulating  (sound-making)  organ  situated 
on  the  articulating  surface  of  one  of  the  peduncular  abdominal  segments, 
which  are  always  extremely  mobile.  Ants  show  few  special  structures  of 
the  kind  so  characteristic  of  the  honey-bee;  that  is,  modifications  of  the 
body  to  suit  the  various  particular  industries  undertaken  by  the  insect.  They 
seem  to  use  the  strong  mandibles  as  universal  tools  to  dig  and  tunnel,  to 
obtain  food,  carry  it  and  manipulate  it,  to  fight,  to  carry  tenderly  their  eggs 
and  young  from  place  to  place,  to  cut  leaves,  husk  seeds,  and  what  not  else. 
While  some  ants  have  the  sting  well  developed  and  capable  of  inflicting  a 
wound  even  more  painful  than  that  of  a  honey-bee,  in  most  of  our  species 

*  Wheeler's  recent  studies  of  the  Ponerine  ants  of  Texas,  referred  to  later  in  this 
chapter,  seem  to  show  that  this  long-believed  generalization  must  be  modified:  the  com- 
munities of  some  of  these  ants  seem  to  be  annual  growths. 


Wasps,  Bees,  and  Ants 


535 


the  sting  is  rudimentary,  short  and  blunted,  and  no  longer  a  weapon.     The 
mandibles  are  relied  on  by  the  stingless  ants  as  means  of  defence  and  offence. 

An  ant  species  always  includes  at  least  three  kinds  of  individuals,  as  a 
social  wasp  or  bee  species  does,  and  may  include  several  more  (Fig.  738). 
There  are  always  winged  males, 
which  die  soon  after  their  issu- 
ance from  the  nest  to  take  part 
in  the  mating-flight  swarm,  and 
winged  females,  or  queens,  which 
pull  off  their  wings  immediately 
after  this  flight.  Thus  winged 
ants  are  to  be  seen  only  at  cer- 
tain seasons  of  the  year,  the 
fertile  females  when  found  in 
the  nest  being  almost  always  in  yig.  738.— A  California  black  ant,  species  un- 
wingless  condition.      In  addition        determined,  showing  winged  forms  and  wing- 

^,  .         1   •     !•    .  1      T      ^1  less    worker.        (After    Jordan    and    Kellogg; 

to  the  wmged  mdividuals   there      ^^^e  natural  size.) 

are  wingless  workers  which   are 

infertile   females,   i.e.,   with  rudimentary  egg-glands   and   lacking   also   the 

spermatheca.     These  workers  in  many  species,  probably  most,  are  of  two 

sizes,  worker  minors  and  worker  majors;    the  two  are  not  wholly  distinct. 


Fig.  739.  Fig.  740. 

Fig.  739. — Soldier  (a)  and  worker  (c)  of  Pheidole  lamia;    b,  head  of  soldier  in  profile. 

(After  Wheeler;   much  enlarged.) 
Fig.  740. — Male  (a)  and  ergatoid  female  (i)  of  Tomognathus  suhlcBvis.     (After  Wheeler; 

much  enlarged.) 

however,  as  intermediate  sizes  are  occasionally  to  be  noted.  In  addition 
there  may  exist  workers  with  extra-large  heads  and  jaws  which  are  known 
as  soldiers  (Fig.  739))  but  also  between  these  and  ordinary  workers  interme- 


53^ 


Saw-flies,  Gall-flies,  Ichneumons, 


diate  stages  are  sometimes  seen.  Finally  there  may  exist  ergatoid  (worker- 
like) wingless  but  fertile  females  and  males.  Wheeler  finds  among  the  ants 
of  the  family  Poneridae,  which  includes  the  most  generalized  or  simplest 
of  the  ant  kinds,  that  the  "queen  and  worker  differ  but  little  in  size  and 
structure;  ergatoid  females  or  forms  intermediate  between  the  queens  and 
workers  are  of  normal  and  comparatively  frequent  occurrence  in  some  species; 
the  habits  of  the  queen  and  workers  are  very  similar;  the  female  is  not  an 
individual  on  whom  special  attention  is  bestowed  by  the  workers,  and  the 


Fig.  741. — The  little  h\sLck  ani,  Mo7tomorium  miniitum.  a,  female;  fc,  female  with  wings; 
c,  male;  d,  workers;  e,  pupa;  /,  larva;  g,  egg  of  worker.  (After  Marlatt;  natural 
size  indicated  by  line.) 

workers  show  no  tendency  to  differentiate  into  major  and  minor  castes." 
This  investigator  has  also  noted  at  the  other  extreme  a  dimorphism  of  the 
queens  (winged  females)  in  Lasius  latipes,  a  member  of  the  specialized  family 
Camponotidae,  and  in  two  genera,  Leptogenys  and  Tomagnathus,  the  absence 
of  any  winged  female,  the  queens  having  become  degenerate  to  the  extent  of 
losing  their  wings.  Hand  in  hand  with  this  differentiation  into  castes  and 
the  accompanying  differences  in  structure  goes,  of  course,  a  division  of  labor 
or  specialization  of  function,  as  will  soon  be  pointed  out. 

We  have  no  such  detailed  and  complete  knowledge  of  the  community 
life  of  ants  as  we  have  of  the  social  wasps  and  bees;   in  particular  we  are 


Wasps,  Bees,  and  Ants  537 

lacking  in  knowledge  concerning  the  exact  mode  or  modes  of  the  estab- 
lishment and  beginning  life  of  new  colonies.  Whether  after  the  mating 
flight  a  fertilized  queen  unaccompanied  by  workers  can  found  a  new  com- 
munity, or  whether  such  fertilized  queens  are  found  after  they  come  to 
the  ground  and  remove  their  wings  and  are  taken  charge  of  by  a  group 
of  workers  which  then  take  the  queen  into  an  already  existing  community 
or  with  her  estabhsh  a  new  one;  or  whether,  as  seems  probable,  most  of 
these  modes  of  procedure  are  repre- 
sented in  the  life-history  of  various  differ- 
ent ant  species — all  these  questions  are 
by  no  means  well  answered  on  a  basis 
of  careful  observation  and  experimenta- 
tion. Most  of  the  observations  which 
have  been  made  on  the  founding  of  new 
communities  seem  to  show  that  a  fertil- 
ized queen  begins  alone  the  establish- 
ment of  a  new  community  by  building  a  Fig.  742. — Soldier  and  worker  of  Phei- 
iVii  i    1      •  f  •         f  dole  commutata.     (After  Wheeler;  en- 

httle   nest,  laying  a  few  eggs,  carmg  for       i^rged.) 

the    hatching    larvae     herself,    and    thus 

raising  by  her  unaided  exertions  a  small  brood  of  neuter  workers  which 
are  always  normally  undersized,  probably  from  insufficient  nourishment. 
This  mode  of  community  founding  is  just  hke  that  obtaining  among 
the  social  wasps  and  the  bumblebees.  Leidy  and  Comstock  have  ob- 
served such  a  mode  of  founding  new  colonies  by  the  common  carpenter- 
ant  of  the  East,  Camponotiis  pennsylvanicus ,  and  in  Europe  Myrmica 
ruginodis,  Camponotus  ligniperdiis,  and  Lasius  alienns  have  been  noted 
to  follow  the  same  procedure.  An  interesting  fact  in  these  cases  is  that 
the  food  given  the  larv£e  by  the  queen  is  supplied  from  her  own  body, 
by  regurgitation  through  the  mouth,  no  food  whatever  being  brought  into 
the  nest  from  the  time  that  the  queen  first  begins  to  lay  eggs  until  this  first 
brood  is  matured.  Wheeler,  whose  admirable  recent  studies  of  American 
ants  have  revealed  many  important  and  intensely  interesting  facts  in  the 
life  of  our  American  ant  communities,  finds  among  the  Ponerine  species, 
undoubtedly  in  most  respects  the  least  specialized  of  the  ants,  that  the  colonies, 
all  of  which  are  small,  "appear  to  be  annual  growths,  formed  by  swarming 
as  in  the  bees,  and  not  by  single  fertilized  female  ants  unaccompanied  by 
workers." 

The  workers  of  the  first  brood  begin  immediately  to  take  on  themselves 
the  work  of  the  little  community,  the  queen  from  now  on  having  only  to  pro- 
duce eggs.  First  of  all  comes  the  enlarging  of  the  nest.  Ants'  nests,  com- 
prising a  sum  of  irregular  chambers  and  galleries,  are  mostly  built  under- 
ground, although  some  have  a  considerable  part  above  the  normal  ground 


538  Saw-flies,  Gall-flies,  Ichneumons, 

surface,  built  up  as  a  mound  or  hillside,  of  more  or  less  symmetry  and  greater 
or  less  size.  This  part  above  ground  may  be  composed  chiefly  or  wholly 
of  soil  brought  up  from  below  surface,  or  may  be  partly  or  wholly  made 
up  of  bits  of  wood,  grass  and  weed  stems,  chaff  or  pine-needles.  The 
nest  may  be  made  under  a  stone  or  log,  or  be  placed  in  a  wholly  exposed 
place.  Most  ants  keep  their  nests  fairly  near  the  surface,  but  a  few  are 
deeply  subterranean  miners.  Still  other  species  tunnel  out  their  corridors 
and  rooms  in  wood — an  old  log  or  stump,  dry  branches,  or  what  not — while 
yet  others  live  in  the  stems  of  plants,  in  old  plant-galls,  in  hollow  thorns  and 
spines;  finally,  a  few  make  nests  of  delicate  paper  or  tie  leaves  together  with 
silken  threads.  Very  wonderful  are  some  of  the  interrelations  between 
certain  plants  and  certain  ant  species  in  tropic  regions,  whereby  the  plant 
seems  to  have  developed  suitable  cavities  for  the  accommodation  of  the 
ants,  whose  presence  is  in  turn  advantageous  to  the  plant  by  the  protection 
it  affords  against  the  ravages  of  certain  leaf-eating  insects  which  are  repelled, 
or  rather  attacked  as  prey,  by  the  ants.  In  many  cases  two  ant  species  will 
live  together  in  a  compound  or  mixed  nest,  the  relation  between  the  two 
species  being  (a)  simply  that  of  two  close  neighbors,  friendly  or  unfriendly; 
(b)  that  of  two  species  having  their  nests  with  "inosculating  galleries"  and 
their  "households  strangely  intermingled  but  not  actually  blended";  (c) 
that  of  one  species,  usually  with  workers  of  minute  size,  which  lives  in  or 
near  the  nests  of  other  species  and  preys  on  the  larvae  or  pupae  or  surrepti- 
tiously consumes  certain  substances  in  the  nests  of  their  hosts — some  different 
larger  species — that  is,  the  relation  of  thief  and  householder;  (d)  that  of  two 
species  living  in  one  nest  but  with  independent  households,  one  of  these 
species  living  as  a  guest  or  inquiline  at  the  expense  of  the  food-stores  of  the 
other,  but  consorting  freely  with  their  hosts  and  living  with  them  on  terms 
of  mutual  toleration  or  even  friendship;  and  (e)  that  of  slave-maker  and 
slave,  a  relation  not  at  all  rare  and  readily  observed  aiU  over  our  country.  In 
addition  certain  other  as  yet  little  studied  cases  of  the  living  together  of  dis- 
tinct ant  species  occur  which,  when  understood,  may  reveal  yet  other  sym- 
biotic relations. 

Inside  the  nest  the  eggs  are  laid  by  the  queen  or  queens  in  large  numbers, 
not  in  separate  cells  as  with  the  wasps  and  bees,  but  in  little  piles  heaped 
together  in  various  rooms  and  sometimes  moved  about  by  the  workers. 
The  hatching  larvae,  tiny,  white,  footless,  helpless,  soft-bodied  grubs,  are 
fed  by  the  workers  either  a  predigested  food  regurgitated  from  the  mouth, 
or  chewed  fresh  insects,  caught  and  killed  by  the  workers,  or  dry  seeds  or 
other  vegetable  matter  brought  into  the  hive  and  stored  in  the  "granary" 
rooms.  A  single  species  of  ant  may  use  all  these  different  kinds  of  food, 
but  for  the  most  part  the  ants  belonging  to  one  species  habitually  do  not. 
The  primitive  food  consists  of  seeds  and  cut-up  insects.      The  importance 


Wasps,  Bees,  and  Ants  539 

of  knowing  the  exact  facts  with  regard  to  this  matter  will  be  appreciated 
when  the  reader  comes  to  the  later  discussion  of  the  probable  origin  of  the 
various  castes  in  the  communal  insect  species.  The  adult  ants  feed  on  a 
variety  of  substances,  both  animal  and  vegetable,  almost  all,  however,  having 
a  special  taste  for  sweetish  liquids,  such  as  the  secreted  honey-dew  of  plant- 
lice,  scale-insects,  certain  small  beetles  and  others,  and  the  sugary  sap  of  cer- 
tain trees.     The  males  and  fertile  females  are  fed  by  the  workers. 

Besides  feeding  the  larvae,  the  nurses  have  to  see  that  the  young  enjoy 
suitable  temperature  and  humidity  of  the  atmosphere;  this  is  accomphshed 
by  moving  the  larvas  or  pupae  from  room  to  room,  farther  below  the  sur- 
face, up  nearer  the  surface,  or  even  out  into  the  warm  sunshine  above 
ground.  The  carrying  about  of  ants'  "eggs,"  which  are  not  eggs  but 
usually  the  cocooned  pupae,  by  the  workers,  is  a  familiar  sight  around  any 
ant-nest,  particularly  a  disturbed  one.  The  various  special  industries  under- 
taken by  ants,  as  the  attendance  on  and  care  of  honey-dew-secreting  plant- 
Hce,  the  fungus-growing  in  their  nests,  the  harvesting  (but  not  planting!) 
of  food-seeds,  the  waging  of  wars  for  pillage  or  slave-making,  the  long  migra- 
tions, etc.,  etc.,  all  more  or  less  familiar  through  much  true  and  some  inaccu- 
rate popular  writing,  will  be  referred  to  in  what  detail  our  space  permits  in 
the  later  descriptions  of  the  life  of  certain  interesting  species  of  American 
ants. 

In  any  community  there  may  live  at  one  time  several  (two  to  thirty) 
queens  with  wings  removed.  In  small  colonies  there  is,  however,  usually 
but  one.  As  already  mentioned,  winged  ants  are  to  be  seen  only  at  certain 
times  in  the  year.  When  a  brood  of  sexual  individuals  (males  and  females) 
is  matured  in  the  community,  these  winged  forms  issue  on  a  sudden  impulse 
(comparable  in  a  way  with  the  outwinging  ecstasy  of  bees  at  swarming- 
time)  from  all  the  openings  of  the  nest  and  take  wing.  The  air  may  be 
swarming  with  them,  flights  from  neighboring  nests  intermingling  and  joining. 
This  is  the  mating  flight,  and  after  it  is  over  and  those  ants  which  have 
escaped  the  bird  attacks  and  other  dangers  attending  this  bold  essay  into  the 
outer  world  ahght  or  fall  exhausted  to  the  ground,  the  males  soon  die,  while 
the  females  pull  the  wings  from  the  body  and  get  under  cover.  In  the  com- 
munal nest,  therefore,  winged  ants  are  rarely  found.  The  life  of  the  workers 
of  most  ant  species  is  conspicuously  longer  than  that  of  other  social  insect 
workers:  they  Hve  for  from  one  to  three  or  four  or  even  five  years.  Lub- 
bock has  kept  workers  until  six  years  old,  and  queens  until  seven.  The 
males  all  die  young,  but  both  other  kinds  of  individuals  are  exceptionally 
long-Uved  for  insects. 

About  two  hundred  species  of  North  American  ants  constituting  the 
superfamily  Formicina  or  Formicoidea  are  comprised  in  three  principal 
families.     Some  authors  recognize  five  or  six  families,  but  it  is  doubtful  if 


540  Saw-flies,  Gall-flies,  Ichneumons, 

such  a  division  of  the  group  can  be  fairly  made.     These  three  famiUes  can 
be  distinguished  by  the  following  key: 

Basal  peduncle  of  the  abdomen  composed  of  a  single  segment  (the  first)  (Fig.    743). 

Abdomen  not  constricted  between  the    second  and  third  segments  (Fig.   743,  i). 

Camponotid^. 

Abdomen  constricted  between  the  second  and  third  segments  (Fig.  743,  2) .  Ponerid^. 
Basal  peduncle  of  the  abdomen  composed  of  two  segments  (Fig.  743,  3) .  .Myrmicid.e. 

Of  these  families  that  of  the  Poneridae  is  the  smallest  in  number  of   species, 
and  includes  the  least  specialized  (as  regards  sharply  marked  division  of 
labor,  differentiation  into  castes,  and   complexity  of 
a     0     ,        ^  ^j^g  communal  life)  of  all  the  ants.     In  the  following 

brief  accounts  of  a  few  of  the  better  known  American 
ants  the  family  relationship  of  each  of  the  species 
referred  to  is  indicated. 

Of  the  Poneridae  only  about  25  species  are  so  far 
known  in  this  country;  all  are  stingers,  although 
not  very  strong  ones,  and  but  a  few  species  are  at 
all  common.  Little  was  known  of  their  habits 
and  life-history  before  the  recent  studies  of  Profes- 
sor Wheeler  on  three  species  occurring  in  Texas, 

Fig.    743. Diagrams    of  namely,    Odontomachus     hcBtnatodes,    Pachycondyla 

lateral  aspect  of  abdo-  harpax,  and  Leptogenys  elongata.     The  nests,  made 

men   of    representatives         j         .  1  ■     ■^-  ^       j. 

of  the  three  families  of  under  stones  or  logs,  are  primitive  structures,  com- 

ants:    i,  Camponotida;;  posed  of  a  few  simple  and  irregular  burrows  or  gal- 

2    Ponerid^;   3,  Mynni-  j     j        ^^^^    ^f  ^^^^^    ^^^   ^^  ^^^    surface  of  the 

cidas.     a,  thorax;   0,  first  '  ® 

abdominal  segment;   c,  soil   immediately  beneath    the    stone  or  log,  while 

second  abdominal  seg-  others    extend    obliquely   or   vertically    downwards 
ment;    a,  third  abdom-    .         .  .      ,  _^,  .  ,         1 

inal  segment.  for   from  8  to  10  inches.     There    are    no    widened 

chambers.  The  nests  of  L.  elongata  comprise  ten 
to  fifty  individuals,  those  of  P.  harpax  fifteen  to  one  hundred,  and  those  of 
O.  hmnatodes  one  hundred  to  two  hundred.  Ergatoid  (worker-like)  females, 
no  larger  than  and  almost  exactly  like  the  true  workers,  existed  in  all  the 
nests;  the  workers  of  none  of  the  species  fed  each  other  or  the  males  and 
females,  and  the  larvae  were  fed  simply  by  giving  them  pieces  of  freshly  killed 
insects,  which  they  chewed  and  devoured  by  means  of  their  unusually  well- 
developed  mandibles.  This  method  of  larval  feeding  is  more  primitive 
(demands  less  care  and  manipulation  on  the  part  of  the  workers)  than  in 
the  case  of  any  other  ants, — indeed  of  any  other  social  insects,  for  even  the 
wasps,  which  also  feed  their  young  pieces  of  insects,  masticate  these  insect 
morsels  thoroughly  before  turning  them  over  to  the  tender  larvae.  The 
feeding  of  the  Ponerine  larvae  is  also  very  irregular  and  capricious  both  as 


Wasps,  Bees,  and  Ants 


541 


Fig.  744. — A      Ponerine     ant,     Leptogenys 
elongata.     (After  Wheeler;    enlarged.) 


to  quantity  and  time.  If  the  regulation  by  the  workers  of  the  kind  and 
quantity  of  food  given  the  larva  is  the  cause  or  one  of  several  influencing 
factors  in  determining  the  caste  or  kind  of  individual  into  which  the  larva 
shall  develop,  as  is  believed  by  most 
students  of  social  insects,  then  the 
unmanipulated  food  of  the  Ponerine 
larvae  and  the  inequality  of  its  con- 
trol as  to  quantity  and  time  of  feed- 
ing may  explain  how  it  is  that  the 
caste  distinctions  are  so  much  less 
marked  in  this  primitive  ant  family 
than  in  the  Myrmicidae  and  Campo- 
notida?,  where,  as  we  shall  see,  the 
character  and  amount  of  the  food 
given  the  larva?  is  carefully  controlled 
by  the  workers. 

The  family  Myrmicidae  includes  a 
large  number  of  our  most  interesting 
ants;  almost  all  are  stingers,  and  all  are  readily  distinguished  from  members 
of  either  of  the  other  families  by  having  the  basal  two  abdominal  segments 
knot-like,  and  forming  the  peduncle.  Some  of  the  Myrmicids  are  well 
known  because  of  their  abundance,  wide  distribution,  and  troublesome  ten- 
dency to  invade  our  houses,  like  the  common  little  red  ant,  Monomorium 
pharaonis,  while  others  are  familiar  through  the  accounts  which  have  been, 
written  by  various  authors  of  their  specialized 
habits.  Among  the  latter  are  the  harvesting  or 
agricultural  ants  (Pogonomyrmex),  a  single  species 
of  which,  the  large  harvester  of  Texas,  P.  barbatus 
var.  molijaciens,  has  had  a  three-hundred-page 
book  devoted  to  it,  and  the  fierce  marauding  ants 
of  the  genera  Eciton  and  Atta  best  known  through 
certain  famous  tropic  kinds,  but  represented  in  this 
country  by  several  thoroughly  interesting  and  char- 
acteristic species. 

Nine  species  of  harvesters  (Pogonomyrmex)  (Fig. 
745)  occur  in  this  country  (in  the  southern,  south- 
western, and  Pacific  coast  states)  all  (except  one 
small  retiring  species)  as  far  as  known  forming  small  or  large  communities 
in  nests  partly  underground  and  partly  heaped  up  in  conspicuous  mounds 
(Figs.  746  and  747)  in  open,  sunny,  and  usually  grassy  places.  They  live 
specially  abundantly  in  the  great  western  plains  and  indeed  in  nearly  desert 
regions.     Into  the  nest  they  bring  great  stores  of  seeds  and  grains,  gathered 


Fig.  745. — An  agricultural- 
ant  worker,  Pogonomyr- 
mex imberbicolus.  (After 
Wheeler;  much  enlarged.) 


542 


Saw-flies,  Gall-flies,  Ichneumons, 


from   the    neighboring  grasses,  and    their  well-marked  runways  make  dis- 
tinct paths  through  the  dense  grass  surrounding  the   nest.     Immediately 


Fig.  746. — Mound-nest    of    the    western    agricultural    ant,    Pogonomyrmex    occidentalis. 
(After  photograph  by  G.  A.  Dean,  Wallace,  Kans.) 

around  the  nest  this  grass  is  cleanly  cut  away.     The  widespread  popular 
belief  that  these  ants  plant  or  sow  (with  purpose  or  intention)  the  seeds  of  a 


Fig.  747. — ^Vertical  section  of  mound-nest  of  the  western  agricultural  ant,  Pogonomyrmex 
occidentalis;  this  nest  about  5  feet  deep  by  6  feet  in  diameter.  (After  photograph 
by  G.  A.  Dean,   Wallace,   Kans.) 

favorite  grass,  Aristida,  is  shown  by  Wheeler  to  be  untrue;   what  does  often 
happen  is  that  the  carrying  out  of  the  chaff  and  sometimes  sprouted  seeds 


Wasps,  Bees,  and  Ants 


543 


(unfit  for  food)  from  the  nest,  and  dropping  them  at  the  edge  of  the  cleared 
circle,  results  in  a  kind  of  unintentional  planting  of  grain  and  grass,  and  as 
Aristida  seeds  make  up  an  exceptionally  large  part  of  the  food-stores,  a 
majority  of  the  plants  in  the  ring  about  the  nest  may  often  be  Aristida.  A 
common  Californian  agricultural  ant,  P.  subdentatus,  found  abundantly  by 
Professor  Heath  at  Monterey,  is  a  splendid  fighter  as  well  as  provident  grain- 
storer,  its  stings  being  declared 
by  Heath  to  be  more  painful  than 
those  of  the  honey-bee. 

Eciton,the  driver-ant,  a  genus 
long  famous  for  the  marauding 
and  pillaging  habits  of  certain 
Brazilian  species  —  in  these 
marches  the  great  procession  is 
said  to  be  marshaled  by  big- 
headed  officers  and  led  by  scouts! 
— is  represented  in  the  south- 
western part  of  our  country  by  a 
few  species,  E.  coeciim,  E.  schmitti, 
E.  opacitherce,  and  others. 
These  show  in  their  life  the  char- 
acteristic habit  of  indulging  in 
maurauding  expeditions  to  the 
nests  of  other  ants  for  the  pur- 
pose of  seizing  and  carrying  off 
the  larvae  and  pupas,  which  are 
used  for  food  by  the  Ecitons. 
Not  all  the  booty  is  devoured 
at  once ;  some  of  it  may  be  stored 
in  the  Eciton  nest  (which  is 
usually  but  a  temporary  habita- 
tion) and  gradually  used  through 
several  days  after  the  expedition. 

The  Ecitons  are  restless  ants,  and  have  a  great  predilection  for  moving  about 
on  long  marches  or  migrations.  On  these  marches  they  carry  with  them  stored 
booty,  which  may  consist  of  the  dead  bodies  of  various  small  insects,  as  well 
as  the  living  larvae  and  pupae  of  pillaged  ant  communities.  The  nests  of 
Eciton  are  entirely  subterranean,  and  are  usually  simply  a  cavity,  partly 
natural,  partly  dug  out  by  the  ants  under  some  sheltering  stone  or  other 
object  lying  in  the  ground.  The  males  and  females  differ  remarkably  from 
the  workers  and  from  each  other  in  appearance,  so  much  so  indeed  that  the 
few  sexual  Eciton  forms  that  have  already  been  discovered  have  mostly  been 


Fig.  748. — Shed-nest  of  Cremastogaster  lineolata, 
18  inches  long  by  12  inches  in  circumference, 
taken  several  feet  from  the  ground  in  a  bur- 
row in  Hyde  County,  North  Carolina;  this  ant 
usually  nests  under  sticks  and  logs.  (After 
Atkinson.) 


544  Saw-flies,  Gall-flies,  Ichneumons, 

first  described  as  members  of  new  genera.     A  flourishing  Eciton   colony- 
may  comprise  several  thousand  individuals. 

Interesting  and  common  Myrmicids  are  the  little  Cremastogasters,  of 
which  one  of  'the  most  abundant  Eastern  species  is  C.  lineolata,  the  shed- 
builder  ant.  It  is  a  small  black  and  yellowish-brown  species,  the  workers 
measuring  from  \  to  yV  i'^^^  ^^  length,  which  usually  lives  in  nests  in 
decaying  logs  or  stumps  or  in  the  ground  under  stones.  But  sometimes  it 
builds  a  nest  out  of  chewed  wood,  like  a  large  rough  gall  attached  to  some 
bush  above  ground.  Atkinson  describes  such  a  nest  (Fig.  748)  18  inches  long 
and  12  inches  in  circumference  which  contained  adults,  larvae,  and  pupae. 
In  addition  to  these  nest-sheds,  small  temporary  sheds  are  sometimes  built 
at  some  distance  from  the  nest  "over  the  herds  of  Aphids,  or  scale-insects, 
from  which  they  obtain  honey-dew." 

Another  interesting  and  abundant  Myrmicid  is  the  minute  yellow  "thief- 
ant,"  Solenopsis  molesta.  Although  it  sometimes  lives  in  independent  nests, 
more  often  by  far  it  is  to  be  found  living  in  association  with  some  larger  ant 
species — it  consorts  with  many  different  hosts — feeding  almost  exclusively 
on  the  live  larvae  and  pupae  of  the  host.  The  thief-ant  is  so  small  and  obscurely 
colored  that  it  seems  to  live  in  the  nest  of  its  host  practically  unperceived. 
The  Solenopsis  nest  may  be  found  by  the  side  of  the  host-nest,  around  it, 
or  partly  in  it,  the  tiny  Solenopsis  galleries  ramifying  through  the  nest-mass 
of  the  host,  and  often  opening  boldly  into  these  larger  galleries.  Through 
their  narrower  passages,  too  narrow  to  be  traversed  by  the  hosts,  the  tiny 
thief-ants  thread  their  way  through  the  other  nest  in  their  burglarious  excur- 
sions. 

As  an  example  of  Myrmicids  which  live  in  compound  or  mixed  nests  the 
species  Myrmica  brevinodes,  a  common  red-brown  ant  that  lives  under  stones 
in  the  East,  and  the  smaller  Leptothorax  emersoni  may  be  referred  to. 
The  interesting  symbiotic  life  of  these  ants  has  been  studied  and  carefully 
described  by  Wheeler  {American  Naturalist,  June,  1901).  The  httle  Lep- 
tothorax ants  live  in  the  Myrmica  nests,  building  one  or  more  chambers  with 
entrances  from  the  Myrmica  galleries,  so  narrow  that  the  larger  Myrmicas 
cannot  get  through  them.  When  needing  food  the  Leptothorax  workers 
come  into  the  Myrmica  galleries  and  chambers  and,  climbing  on  to  the  backs 
of  the  Myrmica  workers,  proceed  to  lick  the  face  and  the  back  of  the  head 
of  each  host.  A  Myrmica  thus  treated  "paused,"  says  Wheeler,  "as 
if  spellbound  by  this  shampooing  and  occasionally  folded  its  antennas  as  if  in 
sensuous  enjoyment.  The  Leptothorax,  after  licking  the  Myrmica's  pate, 
moved  its  head  around  to  the  side  and  began  to  lick  the  cheeks,  mandibles, 
and  labium  of  the  Myrmica.  Such  ardent  osculation  was  not  bestowed  in 
vain,  for  a  minute  drop  of  liquid — evidently  some  of  the  recently  imbibed 
sugar-water — appeared  on  the  Myrmica's  lower  lip  and  was  promptly  lapped 


Wasps,  Bees,  and  Ants 


545 


up  by  the  Leptothorax.  The  latter  then  dismounted,  ran  to  another  Myrmica, 
chmbed  onto  its  back,  and  repeated  the  very  same  performance.  Again  it 
took  toll  and  passed  on  to  still  another  Myrmica.  On  looking  about  in 
the  nest  I  observed  that  nearly  all  the  Leptothorax  workers  were  similarly 
employed."  Wheeler  beheves  that  the  Leptothorax  get  food  only  in  this 
way;  they  feed  their  queen  and  larvze  by  regurgitation.  The  Myrmicas 
seem  not  to  resent  at  all  the  presence  of  the  Leptothorax  guests,  and  indeed 
may  derive  some  benefit  from  the  constant 
cleansing  licking  of  their  bodies  by  the  sham- 
pooers.  But  the  Leptothorax  workers  are  careful 
to  keep  their  queen  and  young  in  a  separate  cham- 
ber, not  accessible  to  their  hosts.  This  is  prob- 
ably the  part  of  wisdom,  as  the  thoughtless 
habit  of  eating  any  conveniently  accessible  pupae 
of  another  species  is  wide-spread  among  ants. 

The  third  family,  Camponotidae,  a  large  one, 
includes  a  majority  of  the  famiHar  ants  of 
eastern  North  America.  The  large  black  car- 
penter-ant, Camponotus  pennsylvanicus  (Fig. 
749),  which  builds  extensive  nests  in  logs, 
stumps,  building  timbers,  and  even  living  trees; 
the  large  black-and-red  mound-builder,  For- 
mica exsectoides,  whose  ant-hills  are  from  five  to 
ten  feet  in  diameter;  and  Lasius  brunneus,  the 
httle  brown  ant  "whose  nests  abound  along  the 
borders  of  roads,  in  pastures,  and  in  meadows," 
are  all  familiar  Camponotid  species.  The  last- 
named  one  is  known  in  the  middle  states  as  the 
corn-louse  ant  because  of  its  interesting  associa- 
tion with  the  wide-spread  corn-root  \o\ise,  Aphis 
maidi-radicis.  In  the  Mississippi  valley  this 
aphid  deposits  in  autumn  its  eggs  in  the  ground 
in  corn-fields,  often  in  the  galleries  of  the  little  brown  ant.  The  following 
spring,  before  the  corn  is  planted,  these  eggs  hatch.  Now  the  little  brown 
ant  is  especially  fond  of  the  honey-dew  secreted  by  the  corn-root  hce.  So  when 
the  latter  hatch  in  the  spring,  before  there  are  corn-roots  for  them  to  feed 
on,  the  ants  with  great  solicitude  carefully  place  them  on  the  roots  of  cer- 
tain kinds  of  knotweed  (Setaria  and  Polygonum)  which  grow  in  the  field, 
and  there  protect  them  until  the  corn  germinates.  They  are  then  removed 
to  the  roots  of  the  corn. 

A  curious  Camponotid  is  the  honey-ant,  Myrmecocystus  melliger,  found 
in  the  southwestern  semi-arid  states.     McCook  studied  these  ants  in  the 


Fig.  749. — Galleries  and  cham- 
bers in  wood  of  the  Eastern 
large  black  carpenter-ant, 
Camponotus  pennsylvanicus. 
(After  McCook.) 


546 


Saw-flies,  Gall-flies,  Ichneumons, 


Garden  of  the  Gods  near  Colorado  Springs,  where  he  found  hundreds  of  the 
low-mounded  nests  in  the  gravelly  soil.  The  name  honey-ant  is  derived 
from  the  curious  structural  modification  and  habits  of  certain  workers,  where- 
by these  become  simply  the  containers  of  stored  honey,  which  fills  out  the 


abdomen  to  the  size  and  shape  of  a  currant  or  small  grape.  These  honey- 
bearers  hang  by  their  feet  from  the  ceiling  of  small  dome-shaped  chambers 
in  the  nest;  their  yellow  bodies  stretch  along  the  ceiling,  but  the  rotund 
abdomens  hang  down  as  almost  perfect  globules  of  transparent  tissue  through 


Wasps,  Bees,  and  Ants  547 

which  the  amber  honey  shines.  The  honey  is  obtained  by  the  workers 
from  fresh  (growing)  Cynipid  galls  on  oak-trees,  which  exude  a  sweetish 
sticky  liquid  which  is  brought  in  by  the  foraging  workers  and  fed  to  the 
sedentary  honey-holders  by  regurgitation.  It  is  held  in  the  crop  of  the 
honey-bearer,  the  distention  of  which  produces  the  great  dilation  of  the 
abdomen.  The  stored  honey  is  fed  on  demand  to  the  other  workers  by 
regurgitation;  a  large  drop  of  honey  issues  from  the  mouth  of  the  honey- 
bearer,  resting  on  the  palpi  and  lips,  and  is  eagerly  lapped  up  by  the  feeding 
individuals,  two  or  three  often  feeding  together.  A  somewhat  similar  honey- 
ant,  Prenolepis  imparls  (Fig.  750),  is  common  in  Cahfornia. 

The  most  interesting,  however,  of  the  familiar  American  ants  are  the 
"slave-makers"  and  their  "slaves."  Three  species  of  slave-makers  occur 
in  North  America,  of  which  two  belong  to  the  family  under  present  discussion. 
These  are  Formica  sangiiinea,  represented  by  five  subspecies,  and  Polyergns 
rujescens,  the  shining  slave-maker,  represented  by  two  subspecies.  The 
third  slave-making  species,  Tomognathus  americanus,  is  a  rare  Myrmicid. 
The  slaves  of  F.  sangiiinea  are  other  smaller  species  of  the  same  genus,  espe- 
cially F.  snbsericea,  F.  nitidiventris,  and  F.  siiboenescens,  while  the  slaves  of 
Polyergus  are  the  same  species  of  Formica  and  the  additional  one,  particu- 
larly common  as  a  slave  form,  F.  schaufussi.  Communities  of  the  slave- 
making  species  are  occasionally  found  in  w^hich  there  are  no  slaves;  when 
slaves  are  present  they  may  be  few  or  many;  usually  they  are  more  numerous, 
proportionally,  the  smaller  the  numbers  of  the  slave-makers  in  any  com- 
munity. The  slaves  are  captured  by  the  attack,  by  a  body  of  slave-making 
workers,  on  a  slave-ant  community  and  of  the  pillage  of  the  attacked  nest  of 
larvae  and  pupae;  some  of  these  may  be  eaten,  but  others  are  brought  back 
unharmed  to  the  slave-makers'  nest.  Here  more  yet  may  be  eaten,  but  most 
are  cared  for  and  soon  hatch  to  become  the  slaves  of  their  captors.  Never 
are  adults  enslaved;  they  are  killed  or  driven  off  during  the  attack.  The 
slaves  undertake  unhesitatingly  all  the  varied  work  of  bringing  in  food,  nest- 
building,  and  caring  for  the  young  in  the  community.  Indeed  in  some  cases 
the  slave-makers  come  to  be  very  dependent  on  the  slaves,  which  ought  really 
then  to  be  called  auxiliaries  or  helpers,  for  the  slave-maker  workers  also 
assist  in  all  the  community  undertakings,  while  the  "slaves"  often  seem 
to  dominate,  or  at  least  to  be  quite  as  important  as,  their  would-be  rulers  in 
the  determination  of  the  course  of  events  in  the  compound  community.  So 
far  does  this  dependence  go  in  the  case  of  certain  foreign  ants  that  the  origi- 
nally dominant  species  loses  its  workers,  and  is  thus  absolutely  dependent 
on  the  auxihary  species  for  the  maintenance  of  the  community.  In  the 
general  division  of  labor  in  the  compound  community  the  fighting  is  always 
done,  at  any  rate  chiefly,  by  the  slave-makers.  McCook  has  described  in 
some  detail  the  community  life  of  the  shining  slave-maker,  Polyergus  lucidus, 


548  Saw-flies,  Gall-flies,  Ichneumons, 

and  its  auxiliary,  Formica  schaujiissi  (Proc.  Phil.  Acad.  Sci.,  18S0,  p.  376 
et  seq.). 

The  observation  and  study  of  ants'  ways  must  be  partly  done  in  the 
field,  but,  thanks  to  the  obhging  manner  in  which  most  species  will  readily 
live  in  artificial  nests  prepared  for  them  indoors,  much  intensely  interesting 
work  in  the  study  of  ants  can  be  done  on  one's  own  reading-table.  Several 
types  of  artificial  formicaries  (ants'  nests)  have  been  devised,  one  by  Lub- 
bock, another  by  Forel,  another  by  Janet,  another  by  White,  etc.,  any  one 
of  which  seems  to  give  good  results.  Professor  Comstock  gives  the  follow- 
ing directions  for  making  a  Lubbock  nest:  "The  principal  materials  needed 
for  the  construction  of  a  nest  of  this  kind  are  two  panes  of  window-glass  ten 
inches  square,  a  sheet  of  tin  11  inches  square,  and  a  piece  of  plank  i\  inches 
thick,  20  inches  long,  and  at  least  16  inches  wide. 

"To  make  the  nest,  proceed  as  follows:  Cut  a  triangular  piece  about 
I  inch  long  on  its  two  short  sides  from  one  corner  of  one  of  the  panes  of  glass. 
From  the  sheet  of  tin  make  a  tray  f  of  an  inch  in  depth.  This  tray  will  be 
a  little  wider  than  the  panes  of  glass  and  will  contain  them  easily.  On  the 
upper  side  of  the  plank  a  short  distance  from  the  edge  cut  a  deep  furrow. 
This  plank  is  to  form  the  base  of  the  nest,  and  the  furrow  is  to  serve  as  a 
moat,  which  is  to  be  kept  filled  with  water  in  order  to  prevent  the  escape 
of  the  ants.  It  is  necessary  to  paint  the  base  with  several  coats  of  paint  to 
protect  it  from  water  and  thus  prevent  its  warping. 

"To  prepare  the  nest  for  use,  place  the  tin  tray  on  the  base,  put  in  the 
tray  the  square  pane  of  glass,  lay  on  the  edges  of  the  glass  four  strips  of  wood 
about  i  inch  wide  and  a  little  thicker  than  the  height  of  the  ants  which  are 
to  be  kept  in  the  nest,  cover  the  glass  with  a  layer  of  fine  earth  of  the  same 
thickness  as  the  strips  of  wood,  place  upon  this  layer  of  earth  and  the  strips 
of  wood  the  pane  of  glass  from  which  one  corner  has  been  cut,  and  cover  the 
whole  with  a  cover  of  the  same  size  and  shape  as  the  upper  pane  of  glass. 
In  the  nest  figured  the  cover  is  made  of  blackened  tin,  and  one-half  of  it  is 
covered  by  a  board.  This  gives  a  variation  in  temperature  in  different  parts 
of  the  nest  when  it  stands  in  the  sunlight. 

"The  ants  when  established  in  the  nest  are  to  mine  in  the  earth  between 
the  two  plates  of  glass.  The  removal  of  one  corner  from  the  upper  pane 
provides  an  opening  to  the  nest.  The  thickness  of  the  strips  of  wood  between 
the  edges  of  the  two  panes  of  glass  determines  the  depth  of  the  layer  of  earth 
in  which  the  ants  live.  This  should  not  be  much  thicker  than  the  ants  are 
high;  for,  if  it  is,  the  ants  will  be  able  to  conceal  themselves  so  that  they  can- 
not be  observed. 

"  The  nest  being  prepared,  the  next  step  is  to  transfer  a  colony  of  ants  to  it. 
The  things  needed  with  which  to  do  this  are  a  two-quart  glass  fruit-can,  or 
some  similar  vessel  that  can  be  closed  tightly,  a  clean  vial,  and  a  garden 


Wasps,  Bees,  and  Ants  549 

trowel.  With  these  in  hand  find  a  small  colony  of  ants,  such  as  are  com- 
mon under  stones  in  most  parts  of  the  country.  Collect  as  many  of  the  ants 
and  of  the  eggs,  larvae,  and  pupae  as  possible,  and  put  them  in  a  fruit-can, 
together  with  the  dirt  that  is  scooped  up  in  collecting  them  with  the  trowel. 
Search  carefully  for  the  queen;  sometimes  she  is  found  immediately  beneath 
the  stone  covering  the  nest,  but  often  it  is  necessary  to  dig  a  considerable 
distance  in  order  to  find  her.  She  can  be  recognized  by  her  large  size.  If 
the  queen  is  not  found,  empty  the  contents  of  th?  can  back  into  the  nest, 
and  take  up  another  colony;  without  a  queen  the  experiment  will  be  a  failure. 
Wh.n  the  queen  is  found  place  her  in  the  vial  so  that  she  shall  not  be  injured 
while  b  ing  carried  to  the  schoolroom. 

"Having  obtained  a  queen  and  a  large  part  of  her  family,  old  and  young, 
return  to  the  schoolroom  and  empty  the  contents  of  the  fruit-can  onto  the 
board  covering  the  upper  pane  of  glass,  and  place  the  queen  there  with  her 
family.  If  much  dirt  and  rubbish  has  been  collected  with  the  ants,  remove 
some  of  it  so  that  not  more  than  half  a  pint  of  it  remains.  When  this  is 
done  leave  the  ants  undisturbed  for  a  day  or  two.  Of  course  the  moat  should 
be  filled  with  water  so  that  they  cannot  escape. 

"Usually  within  twenty-four  hours  the  ants  will  find  the  opening  leading 
into  the  space  between  the  two  panes  of  glass  and  will  make  a  mine  into 
the  layer  or  earth  which  is  there,  and  will  remove  their  queen  and  young  to 
this  place.  This  process  can  be  hastened  by  gradually  removing  the  dirt 
placed  on  the  cover  of  the  nest  with  the  ants. 

"After  the  ants  have  made  a  nest  between  the  panes  of  glass  they  can 
be  observed  when  desired  by  merely  lifting  the  board  forming  the  cover  of 
the  nest. 

"With  proper  care  a  colony  can  be  kept  in  a  nest  of  this  kind  as  long 
as  the  queen  lives,  which  may  be  several  years.  The  food  for  the  ants  can 
be  placed  on  the  base  of  the  nest  anywhere  within  the  moat,  and  may  con- 
sist of  sugar,  minute  bits  of  meat,  fruits,  etc.  With  a  little  care  the  kinds 
of  food  preferred  by  the  colony  can  be  easily  determined.  The  pupae  of 
ants,  which  can  be  collected  from  nests  in  the  field  during  the  summer  months, 
will  be  greedily  devoured.  The  soil  in  the  nest  should  be  kept  from  becom- 
ing too  dry  by  putting  a  little  water  into  one  side  of  the  tin  tray  from  time 
to  time." 

White  prefers  for  a  formicarium  an  inverted  bell-glass  (Fig.  751)  mounted 
on  a  wooden  block  which  is  set  like  an  island  in  a  shallow  pan  of  water. 
"Enough  of  the  contents  of  a  nest  should  be  removed  and  transferred  to 
the  bell-glass  to  occupy  about  half  of  its  available  space.  A  cover  either  of 
baize  or  brown  paper  should  be  placed  over  the  sides  of  the  glass  so  as  to 
conceal  the  contained  earth  and  to  allow  the  hght  to  filter  only  through  the 
surface,  so  that  the  ants  may  be  thus  induced  to  work  against  the  transparent 


550 


Saw-flies,  Gall-flies,  Ichneumons, 


sides  of  the  formicarium.  The  darkness  occasioned  by  the  screen  leads 
them  to  believe  that  they  are  working  underground,  at  certain  distances 
from  the  surface,  and  thus  induces  them  to  construct  many  tiers  of  chambers 
and  connecting  corridors  within  the  range  of  practical  observation.     This 


Fig.  751. — A  convenient  bell-jar  formicary.    The  dish  in  which  the  bell-jar  stands  is  sur- 
rounded by  water  held  in  the  large  zinc  pan. 

we  may  judge  to  our  satisfaction  when,  after  a  few  days,  the  screen  is  with- 
drawn for  a  short  season,  and  the  marvels  of  the  constructive  instinct  of  the 
little  people  reveahd  to  our  wondering  gaze." 

Janet,  a  distinguished  French  student  of  ant  life,  uses  a  block  of  porous 
earthenware  in  which  several    little  chambers  or  hollows  have  been  made» 


Fig    752. — Plan  of  a  Janet  nest,  o,  opening  covered  by  opaque  cover,  c;  wc,  wet  chamber. 

(After  Janet.) 

connecting  with  each  other  by  little  surface  grooves,  the  whole  covered  with 
a  glass  plate,  and  over  that  an  opaque  cover  (Fig.  753).  Into  a  cavity  at 
one  end  of  the  block  he  puts  water  which  soaks  some  distance  along  the 
length  of  the  block,  thus  rendering  some  chambers  humid,  while  others  at 


Wasps,  Bees,  and  Ants 


55^ 


the  far  end  are  dry.  He  gives  the  ants  no  soil,  forcing  them  to  use  the  already 
made  chambers.  This  formicarium  reveals,  therefore,  none  of  the  secrets 
of  nest-building,  but  it  does  reveal  admirably  a  host  of  those  interesting  pro- 
cesses connected  particularly  with  the  life-history  of  the  individuals  of  the 
colony.     Miss  Fielde  uses  still  another  kind  of  nest,  also  like  Janet's  with 


"^"'^    ^ 


r"vi '  T'''-" 


|^^V^^iiSs<.^vWs\\V\\^S^SK^NN^^^^ 


o.rt 

c 


I/. 


Fig.  753. — A  Janet  nest  in  vertical  section,  w.c,  wet  chamber;  i,  2,  3,  brood-chambers; 
o.,  circular  openings  for  brood-chambers  made  in  c,  a  transparent  cover;  o.c,  glass 
cover  in  three  removable  pieces;  d.p.,  opaque  cover;  b.p.,  base  plate.    (After  Janet.) 


fixed  chambers,  but  made  wholly  of  glass,  the  requisite  moisture  being  fur- 
nished by  a  bit  of  sponge  kept  soaked  with  water  and  placed  in  one  of  the 
communicating  chambers.  Fig.  754  with  its  caption  explains  the  make-up 
of  a  Fielde  nest. 

In  the  study  of  the  life  of  ants  by  means  of  such  formicaries  as  have  just 
been  described,  as  well  as  through  observations  in  the  field,  the  student, 
amateur  or  professional,  should  keep  in  mind  certain  particular  desiderata 
in  formicology.  It  is  highly  de- 
sirable to  determine  for  as  many 
species    as     possible     the     exact 


as 
method  of  founding  a  new  colony: 
isolate  a  queen  in  a  small  artifi- 
cial formicary,  well  provided 
with  food,  and  see  if  she  can  and 
will  begin  one;  isolate  a  small 
group  of  workers  with  some  eggs 
or  young  larvae,  but  without  a 
queen,  and  see  if  they  can  and  do 
produce  a  queen  and  estabhsh  pio.  754.  — Plan  of  the  Fielde  ant-nest,  10 
themselves  as  a  permanent  com-  inches  by  6  inches,  a,  entrance  and  exit  to 
munity.  The  characteristic  habits 
of  feeding  the  young  should  be 
determined  for  various  species;  the  presence  of  or  possibility  of  producing 
ergatoid  (wingless,  worker-hke)  fertile  females  and  males  in  the  case  of  vari- 
ous species  should  be  noted;  and  special  attention  should  be  given  in  all 
observations  to  determining  in  how  far  the  behavior  in  general,  and  single  pro- 
cesses in  particular,  can  be  explained  as  machine-like  reflexes  of  unintelligent 


food-rooms  (i);    2,  nursery;  3,  sponge-room; 
b,  screens;   m,  passage. 


55^ 


Saw-iiies,  Gall-flies,  Ichneumons, 


organisms,  or  make  necessary  the  assumption  that  ants  have  a  choice-making 
and  generally  adaptive  and  teachable  intelligence.  Can  ants  dislocate  in 
time  their  reactions  to  stimuli  ?     Are  ants  conscious  ? 

Curious  interrelations  of  ants  with  some  other  animals  have  already 
been  referred  to,  as  their  care  of  plant-lice 
(Aphididte)  from  which  they  obtain  the  much- 
liked  honey-dew,  and  their  association  with  various 
species  of  their  own  general  kind  in  the  rela- 
tions of  slave-maker  and  slave,  host  and  parasite, 
or  host  and  guest.  But  still  another  kind  of  inti- 
mate association  with  other  animal  species  is  com- 
mon in  ant-hfe,  namely,  that  of  the  occurrence  in 
their  nests  of  many  different  species  of  other  in- 
sects (as  well  as  certain  mites,  spiders,  and  myri- 
apods)  which  force  their  presence  on  their  ant 
hosts  by  cleverness  or  deception,  or  are  tolerated 
or  even  encouraged  by  the  hosts.  A  few  of  these 
arthropods  which  inhabit  ants'  nests  are  true  para- 
sites or  predaceous  enemies,  such  as  have  to  be 
endured  by  almost  all  other  insect  kinds,  but  the 
curiously  modified  shape,  large  majority  of  these  so-called  myrmecophiles  do 
(After  Brues;  natural  little  or  no  injury  to  their  ant  hosts,  while  a  few 
length  one-eighth  inch.)  ,  .  ,  ,,  ,         ^  ... 

even  return  m  some  degree  the  advantages  which 

they  receive  by  the  association.  These  advantages  are  (a)  ready-made 
subterranean  cavities  and  lodging-places,  defended  against  most  enemies  by 
the  fierce  and  capable  owners 
of  the  nest;  {h)  a  pleasant 
and  favorable  temperature 
maintained  despite  the  frigid 
ity  of  the  outer  atmosphere; 
(c)  stores  of  vegetable  food, 
as  seeds,  etc.,  garnered  by 
the  ants,  and  supplies  of  ani- 
mal food,  as  bits  of  freshly 
killed  insects,  etc.,  collected  by 
the  hosts,  as  well  as  the  larvae 


Fig.  755. — Ecitoxenia  brevi- 
pes,  a  rove-beetle  (Staphy- 
linidae),  which  lives  in  the 
nests  of  the  robber-ant, 
Eciton  schmittii,  in  Texas. 
Note  absence  of  wings  and 


Fig.  756. 


Fig.  757. 


Fig.  756.  —  Termitogaster  texana,  a  rove-beetle 
(Staphylinidse),  which  lives  in  the  nests  of  the 
termite,  Eutermes  cinereiis,  in  Texas.  (After 
,  J  J  Brues;  natural  length  ij  mm.) 
and  pupae,  and  even  the  dead  yig.  TS7-—^nigmatis  blattoides,  a  Phorid  fly,  which 
bodies  of  the  ants  themselves;  lives  in  the  nests  of  the  ant,  Formica  jiisca,  in 
,  ,x    ^1  .•  1      T      •!    r       1        Denmark.     (After  Meinert;  thirteen  times  natural 

{a)  the    sweetish    liquid    food      ^-^^  \ 

readily  regurgitated    by  most 

ant  workers  in  response  to  certain   stimuli,  and   normally  used  for  feeding 

the  queens,  males,  and  occasionally  other  workers:    and   finally  {e)  means 


Wasps,  Bees,  and  Ants 


553 


of  safe    transportation    due  to  the   migrating   habits  of  many  of  their  host 
species. 

The  myrmecophilous  (ant's-nest-inhabiting)  insects  are  limited  to  no 
single  order.  Of  the  total  of  1177  insect  species  recorded  by  Wasmann 
in  1900  as  living  for  part  or  all  of  their  life  in  ants'  nests,  993  are  beetles,  of 


Fig.  758. — Ant-giiests;  at  left,  Psyllomyia  testacea,  female;  next  at  right,  Ecitomyia 
whecleri,  female;  at  extreme  right,  male  of  last-named  species.  These  two  insects 
are  species  of  flies  of  the  family  Phorida;,  the  females  of  which  have  become 
extremely  degenerate  because  of  their  myrmecophilous  life.  (After  Wheeler; 
much  enlarged.) 


which  the  families  Staphylinidaj  (rove-beetles),  Pselaphidae,  Paussidae,  Clavi- 
geridae,  Histeridas,  Silphidse,  Thorictidae,  Lathridictidae,  and  Scydmaenidae 
make  up  all  but  100  species,  these  latter  representing  22 
other  famihes;  76  are  Hemiptera,  of  which  15  are  plant- 
lice  and  scale-insects;  39  are  Hymenoptera,  of  which  22 
are  other  ant  species;  26  are  Lepidopterous  larvae,  20 
are  Thysanura,  18  Diptera,  7  Orthoptera,  i  a  Pseudo- 
Neuropteron,  34  are  mites,  26  are  spiders,  and  9  are 
isopod  crustaceans.  While  most  of  these  only  derive 
advantage  from  this  commensalism  with  ants,  some,  and 
notably  the  small  Paussid,  Clavigerid,  Pselaphid,  and 
other  beetles,  live  truly  symbiotically  with  their  hosts, 
—  being  of  immediate  reciprocal  benefit  to  them. 
These  little  beetles,  many  of  which  show  most  amazing 
modifications  of  body  structure  (Figs.  755,    756)   (such 

mochfications,  usually  degenerative,  are  displayed  also  by  ^^5.;  7.S9-— Larva  of  a 

.1  .  •      ,     ,     T.,       .  ;  .,.      .^.  Phond  fly  attached 

numerous  other  ant  guests,  particularly  Phond  flies  (Figs.      to  the  larva  of  the 

757'   758),    in    adaptation    to    this   extraordinary    fife, 

secrete  a  sweet  substance   which    is  greedily   eaten  by 

the  ants.     The  hosts  in  return  care  for,  clean,  and  feed 

by  regurgitation  the  curious  little  beetles. 

The  "wonderful"   and  "marvelous"   character  of  the  behavior  of  the 


ant,  Pachycondyla 
harpax.  (After 
Wheeler;  much  en- 
larged.) 


^^4  Saw-flies,  Gall-flies,  Ichneumons, 

ants,  bees,  and  wasps  has  long  been  a  subject  of  popular  interest  and  an 
object  of  much  scientific  observation  and  experimentation  more  or  less 
rigorously  conducted.  Speculation,  both  popular  and  scientific,  concerning 
the  causal  factors  concerned  has  run  a  wide  gamut,  from  the  declaration 
of  Bethe  that  ants  are  simply  complex  machines  responding  mechanically, 
with  fixed  strictly  reflex  reactions,  to  physico-chemical  stimuli,  to  the  anthro- 
pomorphic comparisons  of  the  natura'.-history  popularizer,  who  reads  into 
the  behavior  of  the  "wonderful  little  ant  people"  human  emotions,  human 
reason,  intelligent  discrimination,  and  volitional  action. 

A  difficulty  met  with  at  the  very  beginning  of  any  discussion  of  the  be- 
havior of  social  insects  is  the  lack  of  precise  definitions  of  three  presumably 
classificatory  terms  distinguishing,  on  a  basis  of  cause,  three  kinds  of  behavior 
or  action,  viz.,  reflexes,  instincts,  and  intelligence.  Another  more  funda- 
mental difficulty  in  the  actual  study  and  interpretation  of  animal  behavior 
is  the  absolute  lack  in  ourselves  of  any  criterion  or  means  of  interpretation 
of  action  other  than  our  experience  of  our  own  sensation  and  psychology. 
Nevertheless  the  matter  can  be,  and  is  now  being,  undertaken  in  a  rational 
and  unbiased  spirit,  and  is  attaining  important  positive  results  based  on 
observation  and  experiment  conducted  with  rigorously  scientific  method 
and  expressed  with  scientific  caution.  Although  little  more  than  an  ap- 
preciable beginning  has  been  made  in  this  work,  we  can  already  dis- 
tinguish some  of  the  springs  or  factors,  both  intrinsic  and  extrinsic,  which 
determine  the  actions  of  these  insects,  and  we  can  define  scientifically  some 
of  the  limitations  as  well  as  some  of  the  possibilities  of  their  purposeful 
behavior. 

Between  the  cleanly  mechanical  or  reflex  theory  of  Bethe,  Uexkull,  and 
others,  and  the  reflexes  plus  instincts  and  animal-memory  theory  of  Was- 
mann,  Loeb,  and  Wheeler,  or  between  this  and  the  instincts  plus  intelligence 
theory  of  Lubbock  and  Forel,  there  is  no  sharp  line,  although  between  Bethe 
and  Forel  there  is  a  wide  gulf.  What  modern  investigation  has  clearly  and 
positively  done  is  to  cut  away  the  anthropomorphism  of  the  careless  popu- 
larizer, and  to  compel  a  strong  leaning  toward  a  belief  in  the  efficiency  of 
reflex  and  instinct  to  explain  most  if  not  all  of  ant  behavior.  What  would 
not  have  been  heard  with  any  patience  at  all  a  few  years  ago,  that  is,  a  purely 
mechanical,  i.e.,  reflexive  reaction  to  physico-chemical  stimuH,  explanation 
of  many  of  the  "wonderful"  actions  of  ants,  as  their  perception  of  paths, 
their  recognition  of  nest-mates,  and  swift  attack  on  strangers,  their  refrain 
from  attack  on  other  species  living  in  symbiotic  relations  with  them,  etc.,  etc., 
is  now  heard  with  careful  attention.  Couple  with  this  purely  reflexive  theory 
the  theory  of  inherited  specialized  instincts  developed  by  natural  selection 
from  widely  diffused  generalized  instincts  and  most  of  us  are  incUned  to 


Wasps,  Bees,  and  Ants  555 

find  in  the  combination  the  springs  of  most  if  not  all  ant  behavior;  and  what 
will  explain  the  complex  activities  of  ants  will  certainly  explain  those  of  all 
the  other  so-called  "intelligent  insects,"  namely,  bees  and  wasps,  both  soli- 
tary and  social. 

A  final  problem  in  the  life  of  the  social  insects  is  that  touching  the  origin 
and  establishment  of  the  various  castes  or  kinds  of  individuals  inside  the 
single  species.  The  presence  of  two,  often  widely  differing  kinds  of  indi- 
viduals, namely,  male  and  female,  is  so  familiar  as  to  lose,  for  some  of  us, 
part  of  its  significance  and  importance.  But  why  the  young  produced  by 
the  union  of  male  and  female  can  differ  so  widely  as  they  may,  that  is,  to  the 
extent  of  the  difference  between  male  and  female,  seems  to  us  explicable  by 
the  fact  that  just  such  two  differing  parent  individuals  take  part  in  the  pro- 
duction of  the  new  individuals,  and  by  the  fact  that  such  a  phenomenon 
is  the  usual  and  ordinary  one  of  heredity.  (However  little  we  may  under- 
stand the  natural  phenomenon  or  law  of  heredity  just  as  httle  do  we  under- 
stand gravitation,  which  we  habitually  are  content  to  assign  as  an  ultimate 
cause  for  certain  effects).  But  with  the  social  insects  we  have  always  one, 
and  often  more  than  one,  still  different  individual  among  the  offspring,  and 
one  which  takes  no  part  whatever  in  the  (embryonic)  production  of  new 
individuals;  it  can  hand  on  nothing  to  the  offspring  by  heredity.  The  ques- 
tion is,  then,  how  are  two  kinds  of  individuals  (male  and  female)  able  to 
produce  not  only  their  own  kinds,  but  a  third  kind  which  has  no  part  in  pro- 
ducing or  fertilizing  the  egg-cell  from  which  it  develops? 

And  on  the  heels  of  this  question  comes  a  second.  How  is  it  that  if  the 
present-day  forms  and  kinds  of  animals  are  due  to  the  results  of  the  com- 
bined influences  of  variation,  natural  selection,  and  heredity — that  is,  that 
the  inevitably  appearing  slight  congenital  differences  as  they  are  of  advantage 
or  disadvantage  in  the  life  of  the  animal  are  preserved  or  destroyed  in  the 
species  by  natural  selection — how,  it  may  be  asked,  have  the  characters  of 
the  worker  castes  been  thus  determined  by  selection,  for  in  this  case  the 
modified  individuals  have  no  part  in  the  transmission  of  their  characteristics 
by  heredity? 

The  first  question  is  answered  as  far  as  it  at  present  can  be  in  terms  not 
wholly  agnostic,  by  the  statement  that  it  is  probably  true  among  ants,  as 
has  been  shown  actually  to  be  true  with  certain  other  social  insects,  namely, 
the  termites  (p.  iii)  and  the  honey-bee  (p.  525),  that  the  difference  between 
queen  (fertile  female)  and  worker  (infertile  female)  is  brought  about  during 
postembryonal  development  by  differences  regulated  by  the  nurses  in  the 
quaHty  and  quantity  of  food  supplied  the  developing  individuals.  Sharp 
says:  "There  is  a  considerable  body  of  evidence  suggesting  that  the  quality 
or  quantity  of  the  food  or  both  combined  are  important  factors  in  the  treat- 


556  Saw-flies,  Gall-flies,  Ichneumons, 

ment  by  which  the  differences  are  produced.  The  fact  that  the  social  insects 
in  which  the  phenomena  of  caste  or  polymorphism  occur,  though  belonging 
to  very  diverse  groups,  all  feed  their  young,  is  of  itself  very  suggestive.  When 
we  add  to  this  the  fact  that  in  ants,  where  the  phenomena  of  polymorphism 
reach  their  highest  complexity,  the  food  is  elaborated  in  their  own  organs 
by  the  feeders  that  administer  it,  it  appears  probable  that  the  means  of  pro- 
ducing the  diversity  may  be  found  herein." 

The  answer  to  the  second  query — a  query  anticipated  by  the  keen-minded 
Darwin  as  voicing  an  apparently  insuperable  objection  to  the  selection 
theory — as  made  in  the  Origin  of  Species  at  the  end  of  the  chapter  on  Instinct 
has,  by  the  investigation  of  modern  students  of  ants,  only  been  strengthened. 
This  answer  made  by  Darwin,  and  repeated  with  new  supporting  observa- 
tions and  ingenious  arguments  by  the  present-day  Neo-Darwinians,  is  briefly: 
that  the  differences  between  the  queens  and  the  various  worker 'castes  are 
quantitative  rather  than  qualitative,  that  gradatory  conditions  exist  between 
the  extreme  points  of  the  various  lines  of  structural  and  physiological  speciali- 
zation, individuals  being  found  in  almost  every  ant  species,  so  far  carefully 
studied,  standing  as  connecting  links  between  queen  and  highly  specialized 
infertile  worker  (or  soldier);  that  there  has  been  a  gradual  achievement 
of  this  differentiation  of  structure  through  the  advantage  to  the  species  of 
the  slight  congenital  tendencies  toward  sterility  on  the  part  of  some  of  the 
young,  and  by  consequence  their  special  devotion  to  the  nest  industries,  leav- 
ing the  fertile  individuals  freer  for  reproductive  activity;  that  the  evolution 
has  been  one  of  communities  rather  than  of  individuals;  that  those  fertile 
males  and  females  have  persisted  which  have  shown  a  tendency  to  produce 
some  sterile  individuals  among  their  progeny  which,  living  in  consociation 
with  the  fertile  individuals  of  the  brood,  were  of  special  advantage  to  the 
community  more  and  more  as  they  possessed  such  variations  of  structure 
as  would  fit  some  for  general  work  and  others  for  the  special  defence  of  the 
colony;  and,  finally,  that  such  advantages  to  the  communit}'  have  been 
quite  sufficient  as  handles  for  the  action  of  natural  selection,  with  the  final 
result  as  seen  to-day  in  developing  ant  species  in  which  there  is  a  fairly  :rharp 
division  between  fertile  and  sterile  forms,  and  between  two  or  three  different 
castes  of  the  sterile  individuals.  Those  species  are  the  modern  ones  whose 
fertile  females  produce  several  well-modified  kinds  of  individuals.  Darwin 
and  the  Neo-Darwinians  of  to-day  not  only  find  in  this  answer  an  adequate 
explanation  of  the  development  of  the  modern  highly  specialized  ant  com- 
munity by  the  action  of  natural  selection,  but  find  the  existence  of  such  com- 
munities a  convincing  fact  telling  against  the  belief  of  Lamarckians  and 
Neo-Lamarckians  in  evolution  by  the  accumulation  of  inherited  structural 
and  physiological  characters   acquired  in  the  lifetime  of  individuals.      As 


Wasps,  Bees,  and  Ants  557 

Darwin  says:  "The  case  (of  ant  communities  with  worker  castes)  also  is 
very  interesting,  as  it  proves  that  with  animals,  as  with  plants,  any  amount 
of  modification  may  be  effected  by  the  accumulation  of  numerous,  slight, 
spontaneous  variations,  which  are  in  any  way  profitable,  without  exercise 
or  habit  having  been  brought  into  play.  For  peculiar  habits,  confined 
to  the  workers  of  sterile  females,  however  long  they  might  be  followed,  could 
not  possibly  affect  the  males  and  fertile  females,  which  alone  leave  descend- 
ants. I  am  surprised  that  no  one  has  hitherto  advanced  this  demonstrative 
case  of  neuter  insects  against  the  well-known  doctrine  of  inherited  habit  as 
advanced  by  Lamarck." 

It  will  be  noted  that  the  answer  to  the  first  question  as  to  how  the  marked 
differences  between  the  fertile  and  the  sterile  forms  of  ants  in  any  nest  are 
brought  about  during  individual  development,  and  the  answer  of  Darwin 
to  the  second  question  as  to  how  these  differences  have  been  brought  about 
in  the  species  itself,  are  not  thoroughly  in  harmony.  Darwin's  answer 
would  at  first  glance  seem  to  assume  differences  in  the  eggs  laid  by  a  single 
qu£en  capable  of  determining  the  difference  in  the  individuals  developed 
from  these  eggs;  so  that  no  special  treatment  (feeding)  of  an  individual 
would  be  necessary  to  produce  the  ultimate  differences  in  the  matured  indi- 
viduals. But  the  congenital  differences  may  be  potential  and  not  definitive; 
the  feeding  treatment,  namely,  the  addition  of  certain  extrinsic  or  environ- 
mental factors,  might  be  necessary  to  discover  or  make  actual  the  latent  or 
potential  differences  congenitally  resident  in  the  eggs. 

Still  a  third  question  arises  in  connection  with  the  specialized  conditions 
obtaining  in  modern  ant  communities.  It  is  this:  How  have  the  compound 
and  mixed  communities,  in  which  two  ant  species  live  in  some  kind  or  degree 
of  symbiosis,  arisen  ?  How  has  it  come  about  that  two  species  of  ants  which 
normally  are  deadly  enemies  ready  to  do  battle  with  each  other  at  any  meet- 
ing— a  condition  which  seems  to  be  curiously  general  throughout  the  group 
of  ants,  not  only  different  species  being  always  ready  to  attack  one  another, 
but  members  of  different  communities  of  the  same  species  showing  a  deadly 
animosity  for  each  other — how  is  it  that  these  two  species  have  come  to 
live  peaceably  together  in  a  mixed  community? 

In  the  first  place  in  some  of  the  cases  the  animosity  still  exists;  the  "thief" 
ants  which  live  in  other  ants'  nests  escape  with  their  lives  only  because  of 
their  minute  size  and  obscure  coloring,  their  careful  avoidance  of  detection, 
and  the  care  with  which  they  keep  the  galleries  of  their  own  part  of  the  nest 
too  small  for  the  entrance  of  the  hosts;  they  appear  to  manage  this  double 
household  arrangement  by  vigilance,  cleverness,  and  deceit.  Cases  of  true 
symbiosis  with  mutual  benefit  are  readily  explicable  by  the  selection  theory. 
Their  beginning  is  a  little  hard  to  understand,  but  an  association  with  recip- 


558  Saw-flies,  Gall-flies,  Ichneumons, 

rocal  advantages,  once  begun,  could  readily  be  developed  into  such  a  curi- 
ous condition  as  that,  for  example,  of  Myrmica  and  Leptothorax  described 
on  p.  544.  The  beginning  of  such  an  association  requires  the  assumption, 
of  course,  that  the  apparent  general  rule  of  mutual  animosity  existing  among 
ants  shall  have  its  natural  exceptions;  that  their  instincts  are  not  wholly 
immutable  or  all  embracing.  To  take  a  particular  case,  Wheeler  has  admi- 
rably shown  the  remarkable  differences  of  instinct  exhibited  by  the  species 
of  the  single  genus  Leptothorax.  While  systematists  agree  that  this  large 
and  widely  distributed  genus  is  unusually  homogeneous,  Wheeler  shows 
that  in  habits  its  species  are  singularly  diverse:  "Many  of  the  forms  have 
no  tendency  to  consort  with  ants  of  other  species,  but  differ  considerably 
in  the  stations  which  they  inhabit.  Some  prefer  to  live  under  stones,  others 
in  moss,  others  under  bark  or  in  dead  wood,  and  still  others,  like  one  of  the 
Texan  species,  in  cynipid  galls,  or,  like  our  New  England  L.  longispinosus 
Rog.,  in  the  worm-eaten  hickory-nuts  among  the  dead  leaves  under  the 
trees.  Many  species,  however,  have  a  pronounced  penchant  for  entering 
into  more  or  less  intimate  symbiotic  relations  with  other  Formicida;,  as  shown 
in  the  following  conspectus: 

"i.  The  European  L.  muscoriim  often  lives  in  plesiobiosis  [double  nest] 
with  Formica  nija. 

"2.  A  similar  tendency  is  undoubtedly  exhibited  by  our  American  L.  cana- 
densis Provancher,  which  I  have  had  occasion  to  observe  since  the  second 
part  of  this  paper  was  written."  [Here  Wheeler  describes  in  detail  the 
symbiosis  of  L.  canadensis  and  Cremastogaster  lineolata,  the  common  shed- 
builder  ant  of  the  north  and  east.] 

"3.  L.  pergandei  lives,  probably  as  a  guest,  in  the  nests  of  Monomorium 
miniitiim,  var.  minimum. 

"4.  The  single  colony  of  the  Mexican  L.  petiolatus  which  I  h  ve  seen 
was  living  in  parabiosis  [interlacing  nest]  with  species  of  Cryptocerus  and 
Cremastogaster. 

"5.  L.  tiibenim,  var.  unifasciatus ,  lives  with  the  European  Formicoxenus 
ravouxi,  the  relations  between  the  species  being,  perhaps,  the  same  as  those 
which  obtain  between  Formica  rufa  and  Formicoxenus  nitididiis. 

"6.  L.  muscorum,  L.  acervorum,  and  L.  tuberum  live  as  slaves  or  auxili- 
aries with  the  European  Tomognathus  sublceids. 

"7.  L.  curvispinosus  probably  performs  the  same  role  in  the  nests  of 
T.  Americanus. 

"8.  L.  tuberum  has  been  found  associated  with  Strongylognathus  testa- 
ceus.  Here,  too,  the  Leptothorax  probably  acts  as  the  slave  of  the  dulotic 
species. 

"9.  L.  emersoni  lives  with  Myrmica  brevinodis  as  described  [on  p.  544]." 


Wasps,  Bees,  and  Ants  559 

It  is  evident,  therefore,  says  Wheeler,  that  the  ants  of  this  genus 
have  originally  possessed  certain  traits  which  made  it  specially  easy  for 
them  to  enter  into  symbiotic  relations  with  other  species  of  ants.  Some 
of  these  fundamental  or  original  traits  may  still  be  recognized  in  the  genus, 
to  wit: 

"i.  The  genus  has  a  very  wide  geographical  distribution,  a  prerequisite 
to  the  estabUshment  of  such  numerous  and  varied  relations  with  other  ants. 

"2.  The  species  are  all  of  small  size.  This  must  undoubtedly  facilitate 
their  association  with  other  ants. 

"3.  The  colonies  consist  of  a  relatively  small  number  of  individuals. 
This,  too,  must  greatly  facilitate  life  as  guests  or  parasites  in  the  nests  of 
other  ants. 

"4.  Most  of  the  species  are  rather  timid,  or  at  any  rate  not  belligerent. 
They  are,  therefore,  of  a  more  adaptable  temperament  than  many  other 
ants  even  of  the  same  size  (e.g.,  Tetramorium  coespitiim).  Forel  has 
shown  that  L.  iubero-affinis  will  rear  pupse  of  L.  mylanderi  and  even  of 
Tetramorium  coespUiim  and  live  on  good  terms  with  the  imagines  when  they 
hatch. 

"5.  There  is  no  very  sharp  differentiation  in  habits  between  the  queens 
and  workers  of  Leptothorax.  This,  too,  should  facihtate  symbiosis.  The 
queens,  as  I  have  shown  in  the  case  of  L.  emersoni,  may  retain  the  excavating 
instinct  and  the  instincts  which  relate  to  the  care  of  the  larvae. 

"6.  The  similarity  in  instinct  between  the  queens  and  workers  of  Lepto- 
thorax finds  its  physical  expression  in  the  frequent  occurrence  of  interme- 
diate or  ergatogynous  forms.  So-called  microgynic  individuals,  or  winged 
queens  no  larger  than  the  workers,  have  been  frequently  observed  by  Forel 
and  Wasmann  in  L.  acervorum.  Those  observed  by  the  latter  author  also 
showed  color  transitions  between  the  normal  queens  and  workers." 

Finally,  Wheeler  points  out  that  this  heterogeneity  of  habit  and  these 
existing  gradatory  steps  between  strictly  non-working  fertile  queen  and 
strictly  non-fertile  working-worker,  are  evidence  for  the  selection  theory  as 
explaining  the  division  of  labor  and  differentiation  of  structure  in  the  special- 
ized ant  communities.  "Viewed  as  a  whole,  these  different  symbiotic  rela- 
tions cannot  be  said  to  bear  the  ear-marks  of  internal  developmental  causes 
operating  in  a  perfectly  determinate  manner.  Indeed,  appearances  are 
quite  otherwise  and  seem  rather  to  point  to  indeterminate  variations  which 
have  been  and  are  still  in  process  of  being  seized  on  a  fixed  by  natural  selec- 
tion. It  must  also  be  admitted  that  the  same  appearance  is  presented  by 
the  whole  complex  of  conditions  in  compound  and  mixed  nests,  but  the 
demonstration  is  more  cogent  when  it  can  be  shown  that  we  have  relations 
as  different  as  those  of  dominant  species  {L.  emersoni)  and  slaves  {L.  acer- 


560  Saw-flies,  Gall-flies,  Ichneumons, 

voriim)  not  only  in  the  same  genus  but  among  closely  allied  forms.  This 
fact  also  suggests  that  the  instincts  oj  the  same  species  may  he  so  generalized 
as  to  enable  it  to  junction  like  man,  either  as  a  slave  or  master,  according  to 
the  circumstances.^'' 

And  this  leads  us  to  consider  briefly  that  extremest  form  of  consociation 
between  two  ant  species,  namely,  the  so-called  dulosis,  the  living  together  of 
slave-makers  and  slaves.  To  put  summarily  the  result  of  various  careful 
studies  of  dulotic  communities  made  by  both  European  and  American 
observers,  it  may  be  said  that  this  condition  has  grown  out  of  the  general 
instinct  that  most  ants  show,  to  obtain  when  and  where  possible  the  larvae 
and  pupae  of  other  ant  species  for  food.  From  a  raid  on  a  neighboring  com- 
munity and  the  immediate  devouring  of  as  many  larvje  and  pupse  as  possible 
to  a  similar  attack  and  feast  plus  the  bringing  home  of  a  supply  of  this  choice 
food  to  be  stored  for  eating  through  the  ne.xt  few  days  is  a  natural,  and  as 
exemplified  by  numerous  observed  cases,  an  actual  s  ep.  Then  if  the  booty 
be  large  in  amount,  it  is  inevitable  that  some  of  the  pupae  shall  transform 
in  the  new  nest.  Now,  are  these  newly  issued  workers  to  be  at  once 
attacked  and  eaten?  This  depends  on  whether  the  proper  stimulus  is 
present  or  not.  As  practically  certainly  determined  by  numerous  observa- 
tions and  experiments  the  stimulus  for  attack  and  war  among  ants  (as 
well  as  bees)  is  odor;  recognition  of  nest  mate  and  perception  of  intruder 
or  foreigner  depends  probably  solely  on  the  sense  of  smell,  and  the 
stimulation  of  this  sense  has  come  during  the  evolution  of  the  instincts 
of  ants  to  be  a  stimulus  to  direct  reflexive  action;  the  odor  of  the  home 
community  determines  friendly  behavior,  the  odor  of  any  other  community 
gives  direct  rise  to  attack.  Now,  this  odor  has  several  component  ele- 
ments; one,  for  example,  inherited  (by  the  inheritance  of  a  characteristic 
metabolism)  from  the  queen,  so  that  descendants  of  a  common  mother,  or 
of  sister-mothers  (common  grand-maternal  inheritance),  have  an  odor  with 
something  in  common;  another  element  and  a  strong  one  is,  however,  the 
nest  odor  compounded  of  all  the  individual  odors  in  a  community  and  gradu- 
ally taken  on  by  each  hatching  young.  If  the  young  be  removed  from  one 
community  and  be  hatched  in  another  they  seem  to  take  on  the  odor 
of  the  second  community.  And  so  the  living  booty  brought  back  by  the 
raiders,  issuing  in  the  new  nest,  becomes  endowed  with  the  odor  of  the  new 
community  and  is  unmolested.  But  the  instinct  of  the  hatched  workers 
is  to  work;  and  so  work  they  do.  If  their  work  is  of  advantage  to  the  raider 
community,  natural  selection  will  do  the  rest.  In  the  beginning  there 
were  no  slave-makers;  raiders  there  were  which  raided  other  nests,  not  for 
slaves,  but  for  food.  But  bringing  home  extra  supplies  of  this  food,  which 
hatched  and  lived  and  worked  in  the  new  nest,  evolution  from  food  to  slaves, 
and  from  raiders  to  slave-holders  has  naturally  taken  place.     Now  such 


Wasps,  Bees,  and  Ants 


561 


an  extreme  in  this  specialization  has  been  reached  as  shown  by  Polyergus 
which  is  abjectly  dependent  on  its  slaves.  It  is  no  longer  capable  of  digging, 
is  unable  to  take  enough  food,  unaided  by  its  slaves,  to  keep  it  from  starva- 
tion in  a  nest  stored  to  repletion,  nor  can  it  care  for  its  own  young.  Speciali- 
zation is  leading  Polyergus  to  its  end  1 


CHAPTER   XVI 
INSECTS   AND   FLOWERS 


HE  nectar  of  flowers  is  a  favorite  food  with  many  insects; 
all  the  moths  and  butterflies,  all  the  bees  and  many  kinds 
of  flies  are  nectar-drinkers.      Flower-pollen,  too,  is   food 
for  other  hosts  of  insects,  as  well  as  for  many  of  those 
I  which   take  nectar.     The   hundreds  of  bee   kinds  are  the 

»  most  familiar  and   conspicuous    of  the  pollen-eaters,  but 

many  little  beetles  and  some  other  obscure  small  insects  feed  largely  on 
the  rich  pollen-grains.  But  the  flowers  do  not  provide  nectar  and  pollen  to 
these  hosts  of  insect  guests  without  demanding  and  receiving  a  payment 
which  fully  requites  their  apparent  hospitahty.  And  several  particular 
things  about  this  pa\TTient  are  of  especial  interest  to  us:  these  are,  first, 
the  unusual  character  of  the  payment  received;  second,  the  great  value  of 
it  to  the  plants;  and  finally,  the  strange  shifts  and  devices  which  the  plants 
exhibit  for  making  the  payment  certain. 

In  the  course  of  this  book,  so  far  chiefly  devoted  to  a  systematic  con- 
sideration of  various  kinds  of  insects  and  their  habits,  several  interesting 
ecological  relations  between  plants  and  insects  have  been  referred  to.  That 
plants  furnish  the  nesting-grounds,  or  "homes,"  of  many  insects  has  been 
shown:  the  wood-borers  pass  their  long,  immature  life  concealed  and  pro- 
tected in  burrows  in  the  bark  or  wood  of  trees  and  bushes;  the  delicate  Httle 
leaf-mining  caterpillars  wind  their  devious  tunnels  safely  in  the  soft  tissues 
of  even  the  thinnest  of  leaves;  while  in  more  speciahzed  manner  the  extraor- 
dinary galls  developed  on  the  oaks  and  roses  and  other  plants  serve  as  safe 
houses  for  the  soft-bodied  Cynipid  larvse  enclosed  by  them.  The  making 
of  homes  Uke  these  often,  indeed  usually,  serves  the  double  purpose  of  both 
housing  and  feeding  the  insect;  as  it  gnaws  or  bites  out  its  protecting  bur- 
row in  stem  or  leaf  it  is  getting  the  very  food  it  most  prefers;  as  the  plant 
swiftly  builds  up  about  the  gall-making  larva  masses  of  succulent  tender 
tissue,  it  is  supplying  in  unstinted  quantity  the  very  food  (plant-sap)  which 
the  larva  has  to  have  or  starve. 

But  the  food  relation  may  and  mostly  does  exist  between  plant  and  insect 
without  combination  with  the  nest  or  home  relation.     To  the  countless  hosts 

562 


Insects  and  Flowers 


563 


v.i  plant-feeding  insects,  the  leaf-eating  beetles  and  locusts  and  caterpillars, 
the  sap-sucking  bugs  and  plant-lice,  the  plant  furnishes  food  alone;  and 
in  furnishing  it,  under  a  rough  compulsion,  is  nearly  always  the  loser,  even, 
often  enough,  to  death.  The  special  relation  between  insects  and  plants 
to  which  this  chapter  is  devoted  is  also  a  kind  of  food  relation,  but  with  the 
unusual  character  of  being  one  in 
which  the  plant  is  not  at  all  a  loser 
but  a  gainer,  and  in  as  great  measure 
as  the  insect  itself.  Only  plants  with 
flowers  and  mostly  only  those  with 
bright-colored,  odorous,  and  nectar- 
secreting  flowers,  have  any  part  in 
this  relation,  which  is,  as  the  reader 
has  already  recognized,  that  interest- 
ing phenomenon,  the  cross-pollination 
of  flowers  by  their  insect  visitors. 
As  this  interrelation  of  flowers  and 
insects  is  one  of  very  large  importance 
in  the  life  of  many  insect  kinds,  pro- 
found modifications  of  their  structure 
and  habits  depending  on  it,  and  as 
popular  knowledge  of  the  subject  is 
likely  to  be  extremely  general  in  its 
scope,  I  have  thought  it  advisable  to 
present  a  brief  special  account  of  this 
phenomenon. 

The  agency  of  insects  in  effecting 
the  cross-pollination  of  flowers  has 
long  been  recognized.  Credit  is  given  to 
Sprengel  for  first  pubhshing  accounts 
of  the  interesting  modifications  of 
flowers  due  to  their  interrelation  with 
insects,  and  for  discovering  that  the 
insects  were  instrumental  in  poUinating 
the  flowers.  (Das  entdeckte  Geheim- 
niss  der  Natur  im  Bau  und  in  der 
Befruchtung  der  Blumen,  von  Chris- 
tian Konrad  Sprengel,  Berlin,  1793). 
But  that  this  pollination  by  insects  was  (nearly)  exclusively  cross-pollination 
he  did  not  apparently  fully  understand,  or  at  least  he  did  not  fully  under- 
stand the  significance  of  cross-poflination.  It  was  reserved  for  Darwin 
(On  the  Fertihzation  of  Orchids  by  Insects,  London,  1862),  on  a  basis  not 


Fig.   760  — Snapdragon  being  visited  by 
honey-bees.     (From  nature.) 


5^4 


Insects  and  Flowers 


merely  of  his  acquaintance  with  the  observations  of  Sprengel,  Waechter, 
Delpino,  Hooker,  and.  others,  but  of  characteristically  keen  and  careful 
investigations  of  his  own  (particularly  on  orchids)  to  reveal  the  wide  diffu- 
sion and  great  speciahzation  of  this  interrelation,  and  to  explain  the  causal 
factors  in  determining  the  marvelous  phenomena  attending  its  development. 
These  causal  factors  are  (i)  the  real  advantage  to  the  plant  species  of  cross- 
fertilization,  and  (2)  the  action  of  natural  selection  in  modifying  both  flowers 
and  insects  for  the  sake,  or  by  reason  of,  this  advantage. 

Fertilization  among  plants  is  like  fertilization  among  animals;  a  germ- 
(sperm-)  cell  from  one  individual  (male  or  hermaphrodite)  fuses  with  a  germ- 
(egg-)  cell  from  another  (female  or  hermaphrodite)  individual  or  from  the 
same  (hermaphrodite)  individual.  The  sperm-cells  are  contained  in  pollen 
produced  in  the  anthers  of  stamens;    the  egg-cells   He  in  the  ovaries  at  the 


Fig.  761. — Diagram  of  section  of  pistil  and  ovary  of  a  flower,  'showing  the  descent  of 
the  pollen-tube  and  its  entrance  into  the  ovule,  p.g.,  pollen-grain;  p.t.,  pollen- 
tube;  e.s.,  embryo-sac;  ex.,  egg-cell;  s.n.,  sperm-nucleus.  Left-hand  figure  (i) 
shows  the  pollen-tube  grown  down  around  and  up  into  the  ovary  with  the  sperm- 
nucleus  just  entering  the  ovule;  right-hand  figure  (2)  shows  the  fusion  of  the 
sperm-nucleus  and  egg-nucleus.     (After  Stevens.) 


base  of  the  pistils,  these  pistils  having  an  exposed  pollen-catching  surface 
(stigma)  at  their  free  tip.  Before  actual  fertilization  can  occur  pollination 
must  take  place;  pollination  being  the  bringing  and  applying  of  ripe  pollen- 
grains  to  the  ripe  surface  of  the  stigma.  How  fertilization  then' takes  place 
is  succinctly  explained  by  Fig.  761  and  its  caption,  which  is  copied  from 
Stevens  (Introduction  to  Botany,  Boston,  1902). 

Cross-pollination  is  simply  the  bringing  of  pollen  from  one  plant  indi- 
vidual to  the  stigmas  of  another  individual  of  the  same  species.      Self-pol- 


Insects  and  Flowers  565 

lination  is  the  getting  of  pollen  from  the  stamens  of  one  flower  onto  the 
stigma  of  the  same  llower.  The  advantage  of  cross-pollination,  as  first  experi- 
mentally proved  by  Darwin,  and  since  then  confirmed  by  other  experimenters 
and,  without  scientific  intention  but  none  the  less  effectively,  by  hosts  of 
economic  plant-breeders  (horticulturists,  florists,  etc.),  hes  in  the  fact  that 
the  seeds  produced  when  the  ovules  of  one  plant  are  fertilized  by  the  sperm- 
cells  (in  the  pollen)  of  another  develop  plant  individuals  of  markedly  stronger 
growth  (shown  in  size  of  plant  and  its  fruits,  in  number  of  seeds,  etc.)  than 
seeds  produced  by  the  fertilization  of  ovules  by  sperm-cells  of  the  same  plant. 
To  effect  this  advantageous  cross-pollination  two  lines  of  specialization  or 
modification  of  floral  structures  have  arisen  (presumably  through  the  action 
of  natural  selection):  (i)  modifications  such  as  to  attract  insects  and  insure 
cross-pollination  as  the  result  of  their  visits  (and  to  much  less  extent  to  attract 
other  animals,  particularly  humming-birds),  and  (2)  modifications  tending 
to  prevent  self-pollination.  Coupled  with  both  these  general  lines  of  modi- 
fication are  others  to  effect  certain  auxiliary  or  accessory  conditions  the 
necessity  for  which  grows  out  of  the  larger  needs;  such  are,  for  example, 
modifications  to  prevent  the  stealing  of  nectar  and  pollen  by  other  animals 
(insects  particularly)  than  those  on  which  cross-poUination  specially  depends, 
and  to  make  possible  self-pollination  in  cases  where  cross-pollination, 
although  probable,  may  for  some  accidental  or  other  rare  cause  not  take 
place.  Coincidently,  and  reciprocally  with  the  development  of  modifications 
of  the  flower  structures,  has  occurred  the  specialization  of  certain  structures 
and  habits  among  those  insects  which  are  the  cross-pollinating  agents. 
These  modifications  occur  chiefly  in  the  structure  of  the  mouth-parts  and 
legs  of  bees,  wasps,  flies,  and  a  few  other  insects  and  in  their  food  and 
flight  habits,  and  the  care  of  their  young.  The  reciprocal  modifications 
of  flowers  and  insects  have  gone  so  far  in  some  cases  that  certain  species  of 
plants  and  certain  species  of  insects  cannot  now  live  except  by  virtue  of 
their  inter-relation.  Many  flowers  are  not  fertile  when  pollinated  by  their 
own  pollen,  and  yet  have  no  other  possible  means  of  getting  pollen  from 
other  plants  except  that  of  insect  visits. 

The  principal  means  which  have  been  developed  to  avoid  self-fertihza- 
tion  are  the  following:  (a)  the  having  each  flower  unisexual  instead  of  bi- 
sexual, that  is,  producing  either  pollen  (staminate)  or  ovules  (pistillate)  but 
not  both;  these  unisexual  flowers  may  occur  on  the  same  plant  individual 
(monoecious)  or  on  separate  individuals  (dioecious);  (h)  the  having  both 
pistils  and  stamens  on  each  flower,  but  with  the  anthers  and  the  stigma  not 
maturing  coincidently  (dichogamous),  either  the  anthers  breaking  open 
and  discharging  the  pollen  before  the  stigmas  are  ready  to  receive  it  (pro- 
terandrous)  or  the  stigmas  maturing  before  the  poUen  ripens  and  is  dis- 
charged  (proterogynous) ;    (r)  the  having  the  stamens  and  pistils   (in  the 


^66  Insects  and  P'lowers 

same  flower)  different  in  length  so  that  the  pollen  would  be  unlikely  to  fall 
on  the  stigmas,  or  (d)  the  having  the  stamens  and  pistils  so  situate  with 
regard  to  each  other  that  it  is  difficult  or  very  unusual  for  the  pollen  to  reach 
a  stigma.  All  these  devices  are  familiar  to  every  student  of  botany,  and 
to  gardeners,  florists,  and  flower-lovers  generally,  and  examples  of  them  all 
can  readily  be  found  among  our  common  garden  and  field  plants.  Any 
simple  manual  of  botany  will  put  one  in  the  way  of  hunting  them  out  for 
one's  self. 

To  recur  now  to  the  first  of  the  two  principal  lines  of  speciahzation 
referred  to  as  those  which  have  arisen  in  connection  with  the  advantage 
of  cross-pollination,  namely,  the  modification  of  the  floral  structures,  we 
shaU  find  these  modifications  to  consist  of  (a)  the  secretion  of  nectar  to 
attract  the  insects,  (b)  the  development  of  odor,  color,  pattern,  and  shape 
to  guide  them  to  the  flower  and  when  there  to  the  nectar  and  pollen  in  such 
a  way  as  to  insure  their  brushing  against  both,  or  either,  pollen  and  stigma, 
(r)  the  modification  of  shape  so  as  to  prevent  the  stealing  of  nectar  and 
pollen  by  non-helpful  insects,  and  (d)  the  blossoming  at  those  times  in 
the  year  (seasonal  flowering)  when  the  particularly  helpful  insects  are  most 
numerous,  and  the  opening  of  the  flowers  at  such  times,  in  daylight,  twilight, 
or  at  night,  as  specifically  accords  with  the  food-seeking  flights  of  these 
insects.  The  manifold  variety  of  these  modifications  will  be  indicated  and 
illustrated  by  accounts  of  a  few  specific  cases  exemplifying  certain  more 
or  less  distinct  kinds  of  modification  and  reciprocal  relation  with  insects, 
but  a  few  general  statements  may  first  be  made. 

The  pollen  collected  for  food  by  the  bees  and  a  few  other  insects  is,  of 
course,  a  normal  product  of  the  flower,  and  it  is  only  necessary  that  there 
be  enough  of  it  to  supply  the  insects  and  yet  sufl&ce  for  the  plant's  own  uses, 
i.e.,  in  fertilization.  As  the  oldest,  the  most  primitive,  means  developed 
among  plants  to  effect  cross-pollination,  a  means  still  used  by  all  the  conifers,, 
the  grasses,  and  many  other  plants  mostly  characterized  by  the  total  absence 
of  colored  floral  envelopes  (petals  and  sepals),  is  the  production  of  vast  quan- 
tities of  light,  non-adherent,  pollen  grains  to  be  distributed  by  the  wind, 
the  more  speciaHzed  entomophilous  flowers  (those  depending  on  insects 
to  carry  their  pollen)  probably  started  with  enough  and  more  of  pollen  to 
supply  their  own  needs  as  well  as  the  demands  of  their  visitors. 

The  nectar,  however,  is  a  special  product,  developed  in  direct  connection 
with  the  insect  poUinating  specialization.  It  is  a  "more  or  less  watery  solu- 
tion of  sugar  and  of  certain  salts  and  aromatic  substances  secreted  by  a 
special  tissue  known  as  the  nectary  and  expelled  at  the  surface  through  the 
epidermis  by  breaking  down  of  the  tissues,  or  through  a  special  opening 
of  the  nature  of  a  stoma.  The  nectar  either  remains  clinging  to  the  surface 
of  the  nectary  or  it  gathers  in  large  drops  and  falls  into  a  nectar  receptacle 


Insects  and  Flowers  567 

provided  for  it,  as  in  the  case  of  violets,  where  horn-like  outgrowths  from 
the  two  lower  stamens  secrete  the  nectar  and  pour  it  into  a  cup  formed  by 
the  base  of  the  lower  petal. 

"The  nectaries  may  occur  on  any  part  of  the  flower,  but  they  are  most 
frequently  found  at  the  bases  of  the  stamens,  petals,  and  ovaries,  and  rarely 
on  the  caiyx.  In  the  plum  and  peach  they  form  a  thick  inner  lining  of 
the  cup-shaped  receptacle.  In  nasturtiums  the  nectar  is  secreted  in  a  long 
spur  from  the  calyx. 

"Some  flowers  of  simple  construction  expose  their  nectar  freely  to  all 
sorts  of  insects,  but  others  conceal  it  in  various  ways  so  that  it  is  accessible 
only  to  insects  of  certain  kinds.  A  frequent  device  is  to  have  some  parts 
of  the  corolla  close  over  the  way  to  the  nectar  so  that  small  insects  which 
would  not  assist  in  cross-pollination  are  excluded,  and  only  those  which 
are  strong  enough  to  push  aside  the  barrier  or  have  proboscides  of  proper 
construction  to  thrust  past  it  can  obtain  the  nectar  and  accomplish  the  trans- 
ference of  the  pollen." 

With  nectar  and  pollen  ready  for  the  insect  the  plant  has  yet  to  advertise 
its  sweets,  and  for  that  brilliant  colors  and  attractive  odors  are  relied  on. 
An  attractive  odor  for  insects  is  not  always  pleasing  to  us:  certain  Araceas, 
some  Trilliums,  and  others  have  a  carrion-Hke  odor,  combined  with  "dull 
colors  often  marked  with  livid  blotches  or  veins  like  dead  animal  bodies,  and 
these  flowers  attract  flesh-flies  and  carrion-beetles  which  are  the  pollinating 
agents."  It  appears  from  various  experiments  that  odor  is  the  chief  factor 
in  attracting  insects  from  a  considerable  distance,  and  that  with  the  nearer 
approach  of  the  insect  color  becomes  an  important  guide.  Despite  the 
poor  sight  (formation  of  incomplete  images,  and  this  possible  only  within 
certain  limited  focal  distances)  of  insects  they  appear  to  distinguish  colors 
at  distances  where  the  forms  of  objects  must  be  very  indistinct  to  them. 
Once  attracted  to  the  flower  by  odor  or  color,  or  by  both,  the  pattern  and 
fine  color  streaks  and  spots  play  their  part  in  guiding  them  to  the  nectaries. 
(See  discussion  on  p.  580  of  the  sight  and  color  recognition  of  insects.)  The 
shape  of  the  flower  now  has  also  its  influence;  this  it  is  which  compels  the 
visitor,  in  order  to  get  at  the  nectar,  to  brush  against  the  pollen,  or  the  stigma, 
or  both  as  the  case  demands,  and  thus  to  render  fairly  its  payment  for  the 
special  food  provided.  The  particular  shape  and  make-up,  too,  often  have 
reference  to  the  necessity  of  keeping  away  illegitimate  visitors,  who  would 
drain  the  secreted  stores  without  recompense.  Small  creeping  insects,  as 
ants  (very  fond  of  nectar),  thrips,  and  others  may  be  shut  out  of  the  nectaries 
by  fine,  stiff  little  hairs  densely  set  in  the  throat  of  the  flower-cup,  hke  those 
on  the  stamens  of  spiderwort  or  at  the  bases  of  the  stamens  of  Cobcea  scan- 
dens,  or  may  be  denied  access  even  to  the  flower  itself  by  sticky  glandular 
hairs  on  the  stem  and  leaves.      I  once  counted  nearly  a  hundred  dead  or 


568 


Insects  and  Flowers 


hopelessly  entangled  small  insects  on  the  tall  sticky  stem  of  a  single  Salpo- 
glossus  plant.  But  sometimes  the  burglars  are  successful.  Needham,  in  a 
careful  study  of  the  insect  visitors  on  the  blue  flag  (Iris  versicolor)  near  Lake 
Forest,  111.,  found  a  dozen  or  more  successful  pollen  and  nectar  thieves 
among  them,  while  several  other  would-be  thieves  were  deceived  by  the 
curious  markings  of  the  flower  as  to  the  proper  entrance  and  so  failed  to 


Fig.  762. Blue  flag,  Iris  sp.,  being  robbed  of  nectar  by  skipper-butterfly;  at  left  diagram 

*  shovving  position  of  butterfly's  proboscis  (represented  by  the  arrow)  with  reference 
to  openings  of  the  nectaries.     (After  Needham;    natural  size.) 

make  entry  and  get  to  the  stores.  The  most  persistent  nectar  thieves  were 
several  species  of  Pamphilas  (skipper-butterflies)  which  stood  outside  the 
flower  and  inserted  the  proboscis  obliquely  between  the  sepal  and  the  base 
of  the  style,  plying  and  thrusting  with  it  until  one  of  the  two  holes  leading 
to  the  nectary  is  found  (Fig.  762).  The  actual  pollinating  visitors  were 
chiefly  small  Andrenid  bees. 

It  will  also  be  well  to  note,  before  taking  up  the  special  examples  to  be 
described,  the  general  character  of  the  modifications  which  have  arisen 
among  the  regular  visitors  whose  advantage  in  the  way  of  getting  food  sup- 
plies of  nectar  and  pollen  has  been  sufficient  to  impose,  on  some  of  them 
at  least,  very  considerable  adaptive  structural  changes.  The  great  majority 
of  nectar-drinking  insects  are  bees,  moths,  and  butterflies  and  two-winged 
flies  (of  these  especially  the  Syrphidse).     The  pollen  collectors  are  mostly 


Insects  and  Flowers  569 

bees,  who  use  pollen  not  only  directly  themselves,  but  carry  it  in  quantities 
to  their  nests  as  food  for  their  young,  and  in  the  case  of  honey-bees  for  the 
other  workers  busy  indoors.  To  show  the  affinities  and  the  number  of 
species  of  the  insect  visitors  to  entomophilous  flowers  I  have  compiled  the 
following  figures  from  Robertson's  records  of  his  observations  on  flowers 
in  the  neighborhood  of  Carlinville,  111.  In  twenty-six  observing  days  275 
insect  species  visited  the  flowers  of  Pastinaca  sativa,  of  which  i  was  a  Neurop- 
teron,  6  were  Hemiptera,  9  were  moths  and  butterflies,  14  were  beetles,  72 
were  Diptera,  and  the  rest  Hymenoptera,  of  which  21  were  bees,  39  saw- 
flies  and  parasitica,  and  the  remainder  wasps,  solitary  and  social.  Of  115 
species  visiting  the  milkweed  Asdepias  verticillata,  52  were  Hymenoptera, 
42  Diptera,  16  Lepidoptera,  and  3  Coleoptera;  of  52  species  visiting  Rham- 
nics  lanceolata,  23  were  various  solitary  bees;  of  87  species  found  at  the 
flowers  of  the  willow  Salix  cordata  in  seven  days,  43  were  Hymenoptera,  39 
Diptera,  4  Coleoptera,  and  i  Hemipteron;  112  species  of  insects  visited  Ceano- 
thus  americanus  in  five  days;  79  species  visited  sweet-clover  in  two  days; 
71  species  visited  the  little  spring  beauty,  Claytonia  Virginica,  in  twenty-six 
days,  while  18  species  visited  the  yellow  violet  in  seven  days.  The  hive- 
bee  and  the  bumblebees  are  the  pre-eminent  cross-pollinating  insect  agents, 
some  flowers,  as  clover  for  example,  having  its  pollen  distributed  by  bumble- 
bees alone  (although  Robertson  found  13  different  species  of  butterflies  rob- 
bing nectar  from  red  clover).  The  willow  Salix  humilis,  watched  for  eleven 
days,  had  its  staminate  flowers  wholly  monopolized  by  honey-bees,  although 
51  kinds  of  nectar-feeding  insects  visited  its  pistillate  flowers.  Of  the  488 
species  of  American  entomophilous  flowers  which  have  been  studied  by 
Robertson  I  find  by  going  through  his  records  that  the  honey-bee  visits  nearly 
all,  while  bumblebees  are  recorded  from  a  large  number. 

The  adaptations  for  pollen-gathering  are  mostly  limited  to  bees  and 
consist  of  (a)  the  development  of  hairs,  simple  and  branched  or  feathery, 
specially  situated  to  brush  up  and  hold  the  pollen  grains  as  the  bee  clambers 
over  the  stamens,  and  (b)  in  the  honey-bees  and  bumblebees  the  develop- 
ment of  the  well-known  pollen-basket,  or  corbiculum  (see  description  and 
figure  on  p.  528).  The  adaptations  for  nectar-drinking  consist  in  the  elon- 
gation and  tube-forming  modification  of  the  mouth-parts  of  bees,  flies,  and 
moths  and  butterflies.  While  in  the  less  specialized  bees  the  mouth-parts 
are  short,  with  the  labium  in  the  condition  of  a  short  broad  flap-like  lip 
(Fig.  716),  in  the  specialized  nectar-drinkers,  as  the  bumbles,  the  hive-bee, 
and  the  other  so-called  long-tongued  forms,  the  maxillae  and  labium  are 
long  and  slender  and  the  various  parts  can  be  so  held  together  as  to  form  a 
very  effective  lapping  and  sucking  proboscis  (Fig.  717).  Similar  conditions 
exist  among  the  two-winged  flies  (Diptera);  the  proboscis  of  a  flower-fly 
(Syrphid)  or  bee-fly  (Bombiliid),  for  example,  is  a  long,  slender,  sucking  beak 


570 


Insects  and  Flowers 


very  different  from  the  broad-ended  labellum  of  a  house-fly.  But  it  is  in 
the  Lepidoptera  that  this  speciahzation  of  the  mouth  structure  in  connection 
with  the  nectar-feeding  habit  reaches  its  widest  application  and  the  extreme 
of  its  speciahzation.  Almost  no  other  food  than  nectar  is  taken  by  the  whole 
great  host  of  moths  and  butterflies  (Lepidoptera),  and  throughout  the  order 
the  mouth-parts  are  greatly  modified,  so  as  to  form  a  perfect  flexible,  often 
very  long,  slender  sucking  proboscis  (Fig.  510).  (Some  moths  and  butter- 
flies, however,  take  no  food  at  all  in  the  imago  (winged)  stage  and  these 
mostly  have  only  rudimentary  mouth-parts.)  This  proboscis  is  composed 
of  the  two  greatly  elongated  maxillae  with  their  grooved  inner  faces  so  opposed 
and  locked  together  as  to  form  a  closed  perfect  tube  open  at  its  two  ends,  the 
tip  of  the  proboscis  and  its  base,  the  mouth  (see  p.  361).  By  means  of  an  ex- 
pansion of  the  pharynx,  to  whose  upper  wall  muscles  running  to  the  dorsal 
wall  of  the  head  are  attached,  an  effective  pumping  arrangement  is  obtained,  so 
that  when  the  proboscis  is  thrust  down  a  flower-cup  into  the  nectary  a  stream 
of  nectar  may  be  drawn  up  into  the  throat.  The  proboscis  of  some  moths 
is  very  long  so  as  to  enable  them  to  drink  from  the  deepest  tubular  corollas; 
for  example  that  in  our  larger  sphinx-moths,  like  the  common  tomato-worm 
moth  (five-spotted  sphinx),  is  6  inches  long  (Fig.  509) ;  in  Brazil  there  lives  a 
sphinx-moth,  Macroxilia  cluentius,  with  proboscis  8  inches  long.  An  orchid 
grows  in  Madagascar  with  nectary  12  inches  long,  with  almost  an  inch  of 
nectar  in  the  bottom,  but  the  sphinx-moth,  which  almost  certainly  exists, 
with  a  proboscis  long  enough  to  reach  this  sweet  store  has  not  yet  been  found. 

The  following  few  examples,  showing  varying  degrees  of  specialization, 
illustrate  specifically  many  of  the  already  generally  described  adaptations 
due  to  the  reciprocal  relation  between  flowers  and  insects. 

The  simpler  entomophilous  flowers,  such  as  those  of  the  apple,  cherry,  wild 
rose,  ranunculus,  etc.,  brightly  colored  and  fragrant,  are  mostly  wide  open  and 
accessible  to  a  large  variety  of  insect  visitors.  They  are  all  abundant  pollen 
providers  and  some  secrete  nectar  which  is  easily  got  at.  But  to  get  either 
nectar  or  pollen  the  insects  have  to  scramble  over  and  among  the  many 
crowded  stamens  of  the  center,  dusting  themselves  well  during  the  process 
with  pollen,  which  is  carried  on  to  the  next  flower  visited  and  there  probably 
rubbed  off  on  to  the  stigma.  In  such  simple  forms  the  stigma  of  the  first 
flower  visited  is  Ukely  to  be  fertilized  with  its  own  pollen  by  the  scrambling 
visitors,  if  both  anthers  and  stigma  are  coincidently  mature  (which  in  many 
of  these  flowers  is  not  the  case).  But  even  then  if  the  stigma  is  also  poUinated 
by  foreign  pollen  grains,  it  seems  to  be  more  strongly  affected  by  them  than 
by  its  own  pollen.  Experiments  have  demonstrated  the  superior  potency 
of  the  foreign  pollen  in  actually  effecting  fertilization. 

Open  flowers  of  more  specialization  in  general  botanical  relations, 
although  of  little  more  as  concerns  the  particular  one  under  discussion,  are 


Insects  and  Flowers  571 

the  Umbelliferae  and  the  numerous  Compositas.  In  the  umbels  and  flower- 
heads,  often  rather  inconspicuous  but  nearly  always  well  provided  with 
nectar,  the  sweet  drink  is  easily  got  at  even  by  short-tongued  insects,  so 
that  some  of  the  species  have  a  surprising  host  of  visitors.  For  example, 
Robertson  found  275  different  insect  species  visiting  Pastinaca  sativa  (an 
umbellifer  with  exposed  nectar)  in  the  neighborhood  of  CarHnville,  111.;: 
238  visiting  Ciciita  macidata,  and  191  visiting  Slum  cicutcejoliiim;  observing: 
some  of  the  composites,  more  specialized,  Robertson  noted  146  insect  species 
at  goldenrod  {Solidago  canadensis)  in  eleven  days  during  August,  September, 
and  October,  and  100  at  Aster  panicnlatiis  in  four  days  in  October. 

Of  course  not  all  the  insect  visitors  to  a  flower  are  cross-pollinating  agents; 
some  are  deliberate  thieves,  some  may  or  may  not  help  in  cross-pollination,, 
and  some  are  reliable,  although,  of  course,  unwitting,  pollinators.  As  an 
interesting  test  of  the  proportion  of  actual  pollinators  to  the  whole  number 
of  insect  visitors  may  be  taken  Robertson's  observations  on  the  milkweed 
(Asclepias)  and  its  visitors  (see  account  of  the  conditions  in  Asclepias  on 
p.  573).  Of  115  insect  species  which  visited  flowers  of  Asclepias  veriicillata 
(Carlinville,  111.)  in  fifteen  days,  representatives  of  58  of  these  actually  got 
poflinia  (pollen-masses)  attached  to  themselves;  while  of  80  species  visit- 
ing A.  incarnata  in  twenty-four  days,  63  carried  off  pollinia.  I  do  not  know 
of  any  other  records  which  show  the  proportion  of  actual  pollination  to^ 
total  number  of  visitors,  but  it  is  highly  desirable  that  such  observations 
be  made  for  other  flowers.  Asclepias  obviously  offers  a  particularly  favor- 
able opportunity  for  such  tests  (on  account  of  the  conspicuousness  of  the 
pollinia) ,  but  an  ingenious  observer  will  be  able  to  study  the  matter  success- 
fully with  other  plants. 

With  the  flowers  of  tubular  corolla  the  pollinating  insects  are  of  course 
neither  so  many  nor  do  they  represent  such  varied  insect  groups.  The 
long-tongued  bees  and  flies  can  get  nectar  from  a  flower-cup  not  too  deep, 
but  in  the  deeper  cups  the  moths  and  butterflies  are  the  only  insects  which 
can  reach  the  nectar.  The  common  jimson-weed,  Datura  stramonium,  is,  as 
Stevens  says,  an  excellent  illustration  of  this.  "The  corolla  is  about  five  centi- 
meters long,  and  the  cavity  of  the  tube  is  nearly  closed  at  about  the  middle 
of  its  length  by  the  insertion  of  the  filaments  there.  When  the  flower  opens 
in  the  evening  it  emits  a  strong  musky  odor,  and  a  large  drop  of  nectar  is 
already  present  in  the  bottom  of  the  tube;  so  that  large  sphinx-moths,  leav- 
ing the  places  of  seclusion  occupied  by  them  during  the  day,  are  attracted 
by  the  strong  odor  and  white  color  of  the  flowers. 

"Flying  swiftly  from  flower  to  flower,  the  moth  thrusts  its  long  proboscis 
to  the  bottom  of  the  tube  and  secures  the  nectar;  and  while  it  is  tarrying 
briefly  at  each  flower,  keeping  itself  poised  by  the  swift  vibration  of  its  wings, 
it  is  pretty  certain  to  touch  with  its  proboscis  both  anthers  and  stigmas,. 


572 


Insects  and  Flowers 


which  stand  close  together  at  about  the  same  height  near  the  mouth  of  the 
corolla.  Both  cross-  and  self-pollination  might  be  brought  about  in  this 
vway,  but,  as  Darwin  has  shown,  the  foreign  pollen  would  probably  possess 


Fig.  763. — Hawk -moth  posed  before  a  jimson-weed,  Datura  stramonium. 
Stevens;  one-half  natural  size.) 


(After 


the  greater  potency,  and  cross-fertilization  would  be  apt  to  result.  Fig.  763 
is  a  photograph  of  a  sphinx  moth  and  Datura-flower,  posed  to  show  the  rela- 
tive lengths  of  the  moth's  proboscis  and  the  corolla  tube." 

Another  kind  of  specialization  in  flower  structure  which  tends  to  pre- 
serve the  nectar  for  certain  spe- 
cific insect  visitors  is  well  illus- 
trated by  the  salvias,  the  snap- 
dragon, and  other  similarly 
irregularly  tubular  flowers  (La- 
biate, Leguminosas,  Scrophu- 
lariaceae,  etc.).  Probably  all 
such  flowers  are  pollinated  by 
insects  (a  few  species  by  hum- 
ming-birds). The  irregularity 
in  corolla  is  accompanied  by  a 
specific  disposition  of  the  stamens 
and  pistil,  so  that  the  insect 
visitors  are  compelled  to  visit 
the  nectary  in  one  particular 
manner,  a  manner  devised  to 
insure  their  touching,  or  being 
touched  by,  the  anthers  or  stigma 
or  both.  In  the  snapdragon  (Fig.  760)  the  opening  of  the  flower-cup  is 
normally  closed,  but  when  a  bee  alights  on  the  broad  keel  or  platform  (com- 
posed of  two  petals  grown  together)  its  weight  so  depresses  this  platform  as 
to  open  the  way  into  the  flower-cup,  which  closes  at  once  when  the  bee  goes 
in  and  drinks  the  nectar.  Scrambling  and  twisting  about  in  the  narrow 
chamber  it  thus  thoroughly  dusts  itself  with  pollen,  or  thoroughly  dusts  the 


Fig.  764. — Salvia-flower.  A,  showing  position 
of  pistil  and  stamens;  B,  anthers  of  stamens 
in  normal  position;  C,  anthers  of  stamens 
tipped  down;  D,  bee  entering  flower;  £,  flower, 
natural  condition.  (After  Lubbock;  natural 
size.) 


Insects  and  Flowers 


573: 


stigma  with  pollen  acquired  from  a  previous  visit  to  another  flower. 
Miscellaneous  small  insects  alighting  on  the  keel  are  not  heavy  enough 
to  depress  it,  and  thus  are  prevented  from  entering  and  stealing  the  nectar. 
In  the  salvias  (sages)  the  corolla  is  similarly  tubular  below  and  two- 
lipped  above,  the  lower  lip  serving  as  an  alighting-platform  for  the 
insect  visitors  (usually  bees),  while  the  arched  upper  lip  covers  and  pro- 
tects the  stamens  and  pistil.  In  Salvia  officinalis  (Fig.  764)  the  stamens 
do  not  come  immediately  into  contact  with  the  bee  as  it  enters,  but  they  have 
to  be  moved  in  a  particular  manner,  which  is  accomplished  as  follows:  "TwO' 
of  the  stamens  are  minute  and  rudimentary.  In  the  other  pair  the  two 
anther-cells,  instead  of  being,  as  usual,  close  together,  are  separated  by  a  long 
connective.  Moreover,  the  lower  anther-cells  contain  very  little  pollen; 
sometimes,  indeed,  none  at  all.  This  portion  of  the  stamen,  as  shown  in 
Fig.  764,  hangs  down  and  partially  stops  up  the  mouth  of  the  corolla-tube. 
When,  however,  a  bee  thrusts  its  head  into  the  tube  in  search  of  the  honey,, 
this  part  of  the  stamen  is  pushed  into  the  arch,  the  connectives  of  the  two 
large  stamens  revolve  on  their  axis,  and  consequently  the  fertile  anther-cells 
are  brought  down  onto  the  back  of  the  bee." 

In  the  scarlet  sage  {Salvia  sp.)  cross-pollination  is  accomplished  by 
humming-birds,  which,  hovering  in  front  of  the  narrow  mouth  of  the 
flower-cup,  thrust  deeply  into  it  their  long  bills  in  the  search  for  small  insects 
which  may  have  entered  for  nectar.  Other  flowers  regularly  visited  and 
cross-pollinated  by  humming-birds  are  the  scarlet  currant,  various  painted 
cups  (Castilleias),  the  scarlet  mimulus,  the  wild  columbine,  the  trumpet-creeper, 
the  spotted  touch-me-not,  the  cardinal-flowers,  cannas,  and  fuchsias.  Red 
seems  to  be  the  attractive  color  for  humming-birds.  As  the  only  humming- 
bird species  east  of  the  Rocky  Mountains  is  the  ruby-throat  (Trochilus  ruber), 
this  one  species  is  to  be  credited  with  being  the  chief  pollinating  agent  of  a 
considerable  number  of  flowers;  in  California  and  the  southwest  there  are 
several  species  to  do  the  work. 

Another  marked  and  easily  seen  variant  in  this  specialization  of  flowers 
to  insure  cross-pollination  by  insects  is  that  shown  by  the  milkweeds  of  the 
genus  Asclepias.  Stevens  has  described  this  so  well  (Introduction  to  Botany, 
p.  191  et  seq.)  that  I  simply  quote  here  most  of  his  account.  "Asclepias 
corniiti,  common  everywhere  in  this  country,  is  perhaps  the  best  species  for 
demonstrating  this  [peculiar  specialization  of  the  milkweeds].  As  shown  in 
Fig.  765,  the  sepals  and  petals  are  reflexed;  the  stamens  are  joined  throughout 
their  length,  and  are  united  to  a  thick  and  flat  structure  at  their  apices, 
known  as  the  stigmatic  disk,  which  is  also  united  with  the  top  of  the  two 
pistils.  The  pistils  are  entirely  enclosed  by  the  stamens  and  the  stigmatic  disk. 
Five  spreading,  hollow  receptacles  for  the  nectar  grow  out  and  upward  from_ 
the  bases  of  the  stamens. 


574 


Insects  and  Flowers 


Fig.  765. — Honey-bee  at 
Asclepias  -  flowers,  with 
legs  still  fast  in  a  stigmatic 
chamber  of  the  flower  last 
visited.  (After  Stevens; 
natural  size.) 


"Each  pollen-sac  contains  a  compact  mass  of  pollen-grains  which  never 
become  separated  from  one  another,  and  so  constitute  what  is  termed  a 
pollinium.  The  two  contiguous  pollinia  of  adja- 
cent anthers  are  united  by  horny  rods  which  con- 
verge upward  and  join  with  a  horny  dark  body 
known  as  the  corpusculum,  which  is  hollow  and 
has  a  slit  along  its  outer  face.  This  slit  is  rel- 
atively broad  at  the  bottom,  and  tapers  toward 
the  top,  thus  forming  a  clip  in  which  the  feet  of 
the  insects  get  caught.  Between  each  pair  of 
anthers  there  is  a  deep  recess  closed  by  two  vertical 
lips  which  stand  wider  open  at  the  bottom  than 
at  the  top,  and  the  recess  also  narrows  at  the  top. 
The  opening  between  the  lips  at  the  top  stands 
exactly  beneath  the  slit  in  the  corpusculum. 

"The  surface  of  the  flower  is  slippery,  so  that 
when  a  bee,  for  instance,  visits  it,  a  good  foothold 
is  not  obtained  until  the  bee  shps  its  foot  into  the 
recess  between  the  anthers,  termed  the  stigmatic 
chamber.  Having  obtained  a  foothold,  the  bee 
thrusts  its  sucking-apparatus  into  the  hollow  nectar- 
receptacle  and  obtains  the  nectar  which  has  invited  it  to  the  flower.  When  the 
bee,  however,  seeks  to  go  to  another  flower,  its  foot  slips  upward  and  becomes 
caught  in  the  slit  in  the  corpusculum.  A  struggle 
now  ensues  which  usually  results  in  the  bee  pull- 
ing the  two  pollen-masses,  united  to  the  corpus- 
culum, through  the  narrow  slits  at  the  tops  of  the 
pollen-sacs;  and  thus  laden,  it  seeks  another  flower, 
and  there  slips  its  foot,  together  with  the  pollen- 
masses,  into  the  stigmatic  chamber. 

"Now  when  the  bee  attempts  to  leave  the  flower, 
the  pollen-masses  become  tightly  wedged  at  the 
narrow  apex  of  the  chamber,  and  a  hard  pull  is  re- 
quired to  break  them  loose  from  the  foot.  Finally, 
as  the  foot  is  being  drawn  from  the  stigmatic 
chamber  it  catches  into  the  corpusculum  directly 
above  and  pulls  out  a  second  pair  of  pollen- 
masses.  Thus  the  bee  goes  from  flower  to  flower 
and  from  plant  to  plant,  repeatedly  pulling  pollen- 
masses  from  their    sacs   and   depositing   them    in 

the  stigmatic  chamber.      Fig.  765  is  from  a  photograph    of   a  honey-bee 
gathering   nectar  from  Asclepias-flowers.      One    of   the   hind   legs   is   still 


Fig.  766. — Cabbage-butter- 
fly caught  by  legs  in 
corpuscula  of  two  Ascle- 
pias -  flowers.  (After 
Stevens;  natural  size.) 


Insects  and  Flowers 


575 


held    in    the    stigmatic   chamber   of   the   flower,    which   the    bee    has    just 
deserted." 

Hive-bees,  although  common  visitors  to  Asclepias,  are  really  hardly 
strong  enough  to  insure  pulling  loose  from  the  flowers,  and  many  of  them, 
besides  numerous  flies  and  small  butterflies,  get  caught  and  die  on  the  flower- 
heads.  Robertson  has  noted  nine  species  of  insects  thus  killed  by  A.  cor- 
niiti.  Bumblebees  and  large  wasps  and  large  butterflies  are  the  most  cer- 
tain milkweed  pollinators. 

Still  another  markedly  different  kind  of  specialization  to  effect  cross- 
pollination  by  insects  is  that  shown  by  many  Araceae  and  Aristolochiacese. 
The  flower  (Fig.  767)  in  these  plants  consists  of  a  long  tubular  perianth 
(spathe)  with  a  constriction  near  the  base,  the 
narrow  opening  into  the  cavity  below  being 
nearly  closed  by  stiff  downward-pointing  hairs, 
so  as  to  make  a  sort  of  floral  eel-trap.  It  really 
is  an  insect-trap:  small  flies  crawl  down  the 
long  tube  and  through  the  narrow  opening  in 
search  of  nectar;  but  when  ready  to  return  find 
themselves  imprisoned  by  the  downward-point- 
ing hairs.  After  a  while  the  stigmas  which 
mature  before  the  anthers  and  have  likely 
been  pollinated  (with  pollen  brought  from 
other  flowers)  by  the  entering  insects,  wither, 
a  drop  of  nectar  is  secreted  for  the  benefit  of 
the  captured  insects,  and  the  anthers  mature, 
•exposing  their  ripe  pollen-grains.  The  hairs 
in  the  throat  of  the  flower  gradually  shrivel  up 
and  release  the  insects,  which  are  now  well 
showered  with  pollen  falling  on  them  from  the 
anthers  above.  Visiting  another  Arum-flower, 
they  hardly  fail  to  rub  off  some  of  this  pollen 
on  the  mature  stigmas.  Sometimes  more  than 
a  hundred  smaU  flies  will  be  found  imprisoned  in  a  single  Arum, 

Classic  examples  of  apparently  the  wildest  vagaries  in  flower  structure 
are  those  presented  by  the  orchids.  But  Darwin's  fine  work  revealed  the 
method  in  all  this  floral  madness.  Orchids  are  pollinated  almost  exclu- 
sively by  insects,  and  the  extravagant  shapes  and  color-patterns  are  all  means 
for  accomplishing  cross-pollination.  Any  one  interested  at  all  in  the  inter- 
relation between  flowers  and  insects  should  read  Darwin's  account  of  the 
orchids  and  their  insect  visitors,  in  his  book  "On  the  Fertilization  of  Orchids 
by  Insects."  As  this  book  is  generally  accessible,  I  will  here  only  call  atten- 
tion to  one  new  and  peculiar  feature  generally  characteristic  of  the  speciah- 


FlG.  767. — Flower  of  Aristolo- 
chia  clematitis  in  longitudinal 
section:  A,  before  fertiliza- 
tion by  little  fly;  B,  after  fer- 
tilization, p,  pollen -masses; 
s,  stigma;  b,  bristly  hairs; 
wb,  without  bristly  hairs. 
(After  H.  Miiller.) 


tn(i  Insects  and  Flowers 

zation  in  orchids,  namely,  the  development  of  sensitive  parts  in  the  flow^er, 
so  that  with  a  proper  stimulus  certain  purposeful  motions  or  movements 
are  performed  by  certain  of  the  floral  parts.  Most  of  the  orchids  offer  their 
pollen  in  masses,  pollinia,  which  adhere  to  the  insect  and  are  carried  around 
by  it  during  its  visits  to  other  flowers.  The  stalks  of  these  pollinia  bend 
(by  contracting)  after  they  are  attached  to  the  insect  so  as  to  bring  the  pollen- 
masses  into  the  most  effective  position  for  insuring  contact  with  the  stigmatic 
surfaces  of  the  flowers  visited.  In  the  remarkable  orchid  Catasetum,  a 
certain  part  of  the  flower  is  endowed  with  such  sensitiveness  and  is  nor- 
mally restrained  in  such  a  tense  position  that  when  it  is  touched  by  an  insect 
(or  any  foreign  body)  it  springs  in  such  a  way  as  to  throw  the  pollinia  at 
and  against  the  intruder.  Darwin  once  irritated  one  of  these  flowers  in 
the  presence  of  Lubbock,  who  was  amazed  to  see  the  pollinium  thrown 
"  nearly  three  feet,  when  it  struck  and  adhered  to  the  pane  of  a  window." 

Some  other  flowers,  not  orchids,  also  possess  sensitive  parts;  famihar 
examples  are  various  species  of  Berberis,  whose  stamens  "when  touched 
near  the  base,  as  happens  when  a  bee  is  probing  for  honey,  will  spring  vio- 
lently inward,  shaking  off  the  pollen  and  scattering  it  upon  the  insect  visit- 
ors." Kalmia  presents  a  somewhat  similar  case  "where  the  stamens  are 
bent  over  into  little  pockets,  from  which  they  spring  out  when  touched, 
throwing  the  poUen  to  some  distance." 

In  the  examples  thus  far  chosen  the  flower  has  been  the  more  conspicu- 
ous beneficiary  in  the  partnership,  and  has  shown  the  chief  adaptations. 
The  advantage  to  the  insect  visitor  is  almost  exclusively  a  food  advantage,  and 
its  adaptation  has  been  usually  simply  one  of  the  structure  of  its  mouth-parts. 
But  there  is  known  at  least  one  case  in  which  the  insect  pollinator  does  much 
more  for  itself  by  its  flower  visits  than  find  food  for  immediate  use,  and  in 
which  an  amazing  adaptation  of  habit  has  arisen  on  its  part.  On  the  other 
hand  the  plants  concerned  depend  solely  on  the  one  insect  kind  for  pollination. 
This  is  the  famous  case  of  the  cross-pollination  of  Yuccas  by  the  small  moths 
of  the  genus  Pronuba.  There  are  several  species  of  Yuccas  (Spanish  bayo- 
nets) in  this  country,  and  several  Pronubas,  but  a  brief  account  (taken  largely 
from  Stevens's  Introduction  to  Botany)  of  the  relations  between  the  com- 
mon Yucca  grown  in  gardens  (F.  filamentosa)  and  the  moth  species,  Pronuba 
yuccasella,  will  be  typical  of  the  interrelations  of  all. 

The  Yucca  has  a  lily-like  flower  composed  of  three  sepals  and  three 
petals,  ah  creamy  white,  six  stamens  with  fleshy  outward-curving  filaments 
surrounded  by  small  anthers,  and  a  pistil  extending  much  above  the  tops 
of  the  stamens  with  three  carpels  imperfectly  united  at  the  top,  and  thus 
leaving  a  tube  entirely  open  at  the  apex.  "The  inner  surface  of  this  tube 
is  stigmatic.  This  stigmatic  tube  does  not  open  directly  into  the  cavities 
of  the  ovary,  but  sends  off  three  very  narrow  branches,  each  of  which  com- 


Insects  and  Flowers 


S71 


municates  with  the  cavity  of  a  carpel.  Accordingly,  when  pollen  is  once 
deposited  on  the  inner  surface  of  the  main  stigmatic  tube,  the  pollen-tubes 
find  easy  access  to  the  ovules  in  each  of  the  three  carpels.  The  pollen  is 
sticky  and  hangs  together  in  masses,  so  that  it  is  not  adapted  to  being  carried 
by  the  wind,  and  it  is  apparently  impossible  for  it  to  get  to  the  stigmatic 
tube  without  some  outside  agent. 

"A  small  amount  of  nectar  is  secreted,  but  it  is  excreted  at  the  very  base 
of  the  pistil,  so  that  insects  seeking  it  would  be  far  removed  from  the  sti'gmas. 
Indeed,  the  low  position  of  the  nectar  would  seem  rather  to  lead  insects  away 
from  the  stigmas.  The  flowers  are  borne  in  compound  racemes  high  aloft 
on  a  strong  woody  shaft,  and,  because  of  their  rather  strong  odor  when  new 
buds  are  opening  in  the  evening  and  their  white  color,  they  are  quite  cer- 
tain to  make  their  presence  known  to  insects  flying  in  the  twilight. 

"If  we  take  these  facts  as  our  clew  and  attentively  watch  these  flowers 
about  eight  o'clock  in  the  evening,  the  method  of  cross-pollination  will  be 
made  clear.  A  white  moth,  known  as  the 
Pronuba-moth,  is  seen  to  mount  a  stamen, 
scrape  together  the  sticky  pollen,  and 
pack  it  against  the  under  side  of  its  head 
by  means  of  a  spinous  structure  known 
as  the  maxillary  tentacle,  which  seems 
to  have  been  specially  developed  for  this 
purpose,  for  in  other  moths  it  is  a  mere 
vestige.  In  gathering  the  pollen  it  hooks 
its  tongue  over  the  end  of  the  stamen, 
evidently  to  secure  a  better  hold.  Having 
become  well  loaded  with  pollen,  as  shown 
in  the  photomicrograph  of  the  moth's 
head,  it  descends  the  stamen  and  flies 
to  another  flower.  There  it  places  itself 
on  the  pistil  between  two  of  the  stamens 
(see  Fig.  768)  and  thrusts  a  slender  ovipositor  through  the  wall  of  the  ovary 
and  into  the  cavity  occupied  by  the  ovules. 

"Having  deposited  an  egg,  it  ascends  the  pistil,  and  by  means  of  the 
maxillary  tentacles  and  tongue,  which  at  other  times  are  coiled  around  the 
load  of  pollen,  it  rubs  pollen  down  the  inner  surface  of  the  stigmatic  tube. 
Fig.  769  is  a  [drawing  made  from  a]  flashlight  photograph  of  a  moth  performing 
this  act.  The  moth  then  descends  the  pistil,  and  standing  between  another 
pair  of  stamens  it  deposits  another  egg  within  the  ovary;  then  it  ascends 
the  pistil  and  rubs  pollen  on  the  stigmatic  surface  as  before.  This  process  is 
repeated  until  it  may  be  that  each  of  the  six  lines  of  ovules  is  provided  with  an 
egg,  and  the  process  of  pollination  has  been  as  many  times  accomplished. 


Fig.  768. — Pronuba-moth  depositing 
eggs  in  ovary  of  Yucca.  (After 
Stevens;  natural  size.) 


sji 


Insects  and  Flowers 


Fig.  769.  —  Pronuba-moth  rubbing 
pollen  down  the  stigmatic  tube  of 
Yucca.  (After  flash-light  photo- 
graph by  Stevens;  natural  size.) 


"The  full  meaning  of  this  wonderful  series  of  operations  will  not  be 
understood  until  subsequent  developments  have  been  followed.  Since  the 
process  of  poUination  has  been  so  thoroughly  done,  most  of  the  numerous 

ovules  become  fertilized  and  the  seeds 
begin  their  development.  In  the  mean  time 
the  moth  eggs  hatch  into  larvae,  which  find 
their  food  in  the  developing  seeds.  But  the 
seeds  are  so  numerous  that  the  larvae  reach 
their  growth,  gnaw  a  hole  in  the  seed-pod 
and  escape,  while  many  uninjured  seeds 
still  remain  in  the  pod.  The  larva  spins 
a  thread  by  which  it  descends  to  the 
ground,  and,  burrowing  beneath  the  sur- 
face, it  passes  the  winter  in  its  pupal 
state,  emerging  as  a  fully  developed  moth 
at  the  time  of  the  flowering  of  the  Yucca 
the  following  summer. 

"It  appears  that  the  mature  moth  takes 
no  food,  unless  it  secures  some  of  the 
nectar  of  the  Yucca  blossoms  in  which  it 
is  wont  to  pass  the  day,  with  its  head  close 
to  the  bottom  of  the  flower  where  the  nectar 
is  excreted.  It  does  not  eat  the  pollen  which  it  gathers,  and  it  seems  certain 
that  it  is  prompted  to  place  the  pollen  in  the  stigmatic  tube  after  each  act 
of  oviposition  solely  by  the  instinct  to  provide  for  its  young;  for  it  is  readily 
understood  that  if  the  ovules  are  not  fertilized  the  seeds  would  not  develop 
and  the  larvae  would  be  without  food. 

"The  Yucca  flower,  instead  of  having  elaborate  devices  to  secure  cross- 
pollination,  simply  prohibits  self-pollination  by  its  tubular  stigmas  and  its 
relatively  short  and  reflexed  stamens;  and  then,  the  sticky  pollen  and 
an  abundance  of  ovules  being  provided,  the  performance  of  pollination 
is  intrusted  to  the  wise  instinct  of  the  Pronuba-moth;  and  not  pollina- 
tion simply,  but  cross-pollination,  for  it  has  been  noticed  that  it  is  the  habit 
of  the  moth  after  securing  the  pollen  to  fly  to  another  flower  before  it  begins 
to  lay  its  eggs."  (This  extraordinary  interrelation  between  Yucca  and 
Pronuba  was  discovered  and  carefully  studied  by  C.  V.  Riley  in  1872,  and 
his  intensely  interesting  detailed  accounts  of  his  observations  are  to  be  found 
in  Vol.  3  Trans.  St.  Louis  Acad.  Sci.,  his  5th  and  6th  reports  as  state  ento- 
mologist of  Missouri,  and  in  the  3d  Ann.  Rept.  of  the  Missouri  Botanical 
Garden) . 

The  above  various  and  interesting  examples  of  the  interrelations  between 
flowers  and  insects  are  not  exceptional  cases;    indeed  this  state  of  affairs 


Insects  and  Flowers  579 

with  its  accompanying  mutual  adaptation  is  the  rule  throughout  the  families 
of  flowering  plants,  the  Spermatophyta.  The  absence  of  it  is  the  exception; 
cross-pollination  is  far  more  abundant  than  self-pollination.  And  the 
devices  by  which  it  is  brought  about  are  in  their  details  almost  as  many 
and  as  various  as  are  the  different  shapes  and  color-patterns  of  flowers. 
The  student  who  may  be  interested  to  learn  what  flowers  have  been  studied 
to  discover  the  kinds  of  insect  visitors  and  the  character  of  the  modifications 
that  have  arisen  for  the  sake  of  cross-pollination  should  refer  to  the  many 
papers  (published  in  the  Botanical  Gazette,  Trans.  St.  Louis  Acad.  Sci., 
and  elsewhere)  of  Robertson,  who  between  1886  and  1895  studied  488  species 
of  American  insect-pollinated  flowers;  to  Lubbock's  "British  Wild  Flowers 
in  Relation  to  Insects,"  in  which  similar  studies  on  English  flowers  are 
recorded;  to  H.  Miiller's  "Fertilization  of  Flowers,"  a  bulky  volume  of 
observations  on  European  insect-pollinated  flowers  together  with  much  more 
general  discussion,  and  a  detailed  consideration  of  the  structure  of  the 
most  important  insect  poUinators;  to  the  same  author's  "Alpenblumen," 
an  account  of  the  relation  between  insects  and  the  flowers  of  the  Alps;  and 
to  Darwin's  book,  already  mentioned,  on  the  fertilization  of  orchids  by  insects. 

It  is  plain  that  this  fact  of  the  adaptation  of  flower  structure  and  pat- 
tern for  the  sake  of  cross-pollination  by  insects  explains  a  great  deal  of  the 
manifold  variety  of  form  and  color-marking  which  exists  among  flowers. 
The  adaptation  of  the  flower  to  its  insect  visitors  goes  even  farther:  to  a  cer- 
tain extent  the  flowering  season  of  many  plants  is  determined  by  the  time 
of  the  appearance  in  winged  stage  of  its  more  important  insect  visitors. 
Robertson  sums  up  his  interesting  observations  concerning  this  fact  (based 
on  the  study  of  nearly  500  plant  species  and  their  insect  visitors)  as  follows: 
"We  have  reviewed  the  principal  groups  of  insect-pollinated  plants  and 
have  noted  a  correspondence  more  or  less  well  marked  between  their  bloom- 
ing seasons  and  the  seasons  of  the  insects  upon  which  they  depend."  But 
it  is  only  fair  to  presume  that  the  insects,  at  least  those  which  get  a  large 
amount  of  food  from  the  flowers,  may  have  become  adapted  as  to  their  flight- 
time  in  some  degree  to  the  blossom-time  of  their  host-flower.  That  this  is 
true  of  the  bees,  which  get  practically  all  of  their  food  (pollen  and  nectar), 
both  for  themselves  and  for  their  young,  from  flowers,  seems  certain. 

But  the  easy  and  sweeping  way  in  which  this  theory  has  been  made  to 
explain  the  immense  variety  and  often  intricate  condition  of  floral  struc- 
ture and  pattern  has,  naturally  and  wisely,  led  to  a  more  rigid  scrutiny 
of  its  all-sufficiency  for  the  explanation  of  floral  variety.  It  is  apparent  of 
course  that  flowers  in  their  fundamental  structural  character  are  controlled 
largely  by  heredity,  and  this  heredity  is  largely  an  expression  of  phylogeny, 
that  is,  ancestral  history.  Flowers  of  close  natural  relationship  are  bound 
to  be  more  alike  than  those  widely  separated  genealogically.     But  beyond 


^8o  Insects  and  Flowers 

this  there  really  seems  to  be  no  other  explanation  of  flower  shape  and  appear- 
ance having  the  same  validity  as  that  of  adaptation  to  insect  visitors. 

The  most  effective  criticism  of  this  explanation  is  one  against  its  effective- 
ness in  explaining  color,  and  particularly  color-pattern.  It  is  based  on  the 
general  consensus  of  belief  among  zoologists  and  entomologists  concerning 
the  poorness  of  insect  vision.  The  general  character  of  this  vision,  with  an 
account  of  the  eye  structure,  is  explained  on  pp.  30-33  of  this  book.  The 
fixed  short  focal  distance,  the  incompleteness  and  lack  of  detail  incident  to  a 
mosaic  image,  and  the  lack  of  accommodation  (only  partly  provided  for  by 
the  shifting  of  the  peripheral  pigment)  to  varying  light  intensity,  which  are 
admitted  conditions  of  insect  vision,  make  it  seem  difficult  to  account  for  the 
intricacy  in  pattern  common  to  many  flowers  on  a  basis  of  adaptation  to 
animal  visitors  of  such  poor  seeing  capacity  as  insects. 

Experimental  evidence  touching  this  criticism  is  singularly  meager  when 
one  considers  the  importance  of  the  subject.  If  insects  can  accurately  dis- 
tinguish colors,  and  at  some  distance,  and  can  perceive  fine  and  intricate 
details  of  color-pattern  at  very  short  distance,  then  the  explanation  of  floral 
structure  and  pattern  or  adaptation  to  insect  visitors  has  solid  foundation 
for  even  the  amazingly  large  and  varied  results  which  it  attempts  to  explain; 
if  not,  it  is  hard  to  understand  how  the  explanation  is  vahd  (at  least  in  any 
such  all-sufficient  degree  as  commonly  held),  despite  its  logical  character 
(in  the  Hght  of  our  knowledge  of  the  nearly  limitless  capacity  for  modifica* 
tion  of  natural  selection)  and  the  abundant  confirmatory  evidence. 

Most  of  the  experimental  evidence  so  far  offered  is  that  included  in  Dar- 
win's account  ("  On  the  Fertilization  of  Flowers  by  Insects  ");  in  Lubbock's 
account  of  his  experiments  on  honey-bees,  familiar  because  of  its  presentation 
in  his  readable  book,  "Ants,  Bees,  and  Wasps";  and  in  Plateau's  account 
of  his  more  recent  but  less  familiarly  known  experiments  with  various  insects, 
including  bees.  Both  Lubbock  and  Plateau  are  investigators  ingenious 
in  device,  keen  in  deduction,  and  of  unquestioned  scientific  honesty.  Yet 
their  conclusions  are  in  direct  contradiction.  Lubbock  believes  that  bees 
recognize  colors  at  a  considerable  distance,  that  they  "prefer  one  color  ta 
another,  and  that  blue  is  distinctly  their  favorite."  Plateau  finds  that  neither 
the  form  nor  the  brilliant  colors  of  flowers  seem  to  have  any  important  attrac- 
tive role,  "as  insects  visit  flowers  whose  colors  and  forms  are  masked  by 
green  leaves,  as  well  as  continue  to  visit  flowers  which  have  been  almost 
totally  denuded  of  the  colored  parts";  that  insects  show  no  preference  or 
antipathy  for  different  colors  which  flowers  of  different  varieties  of  the  same 
or  of  aUied  species  may  show;  that  flowers  concealed  by  fohage  are  readily 
discovered  and  visited;  that  insects  ordinarily  pay  no  attention  to  flowers 
artificially  made  of  colored  paper  or  cloth  whether  these  artifacts  are  provided 
or  not  with  honey,  while,  on  the  contrary,  flowers  artificially  made  of  Uving 


Insects  and  Flowers  581 

■green  leaves  and  provided  with  honey  are  visited  (from  the  attraction  of  the 
"natural  vegetable  odor").  From  these  observations  Plateau  concludes 
that  "insects  are  guided  with  certainty  to  flowers  with  pollen  or  nectar  by 
a  sense  other  than  that  of  vision  and  which  can  only  be  that  of  smell,"  and 
finds  particular  proof  of  this  in  the  facts,  according  to  his  observations,  (i) 
that  insects  tend,  without  hesitation,  towards  flowers  usually  neglected  by 
reason  of  the  absence  or  poverty  of  nectar,  from  the  moment  that  one 
supplies  these  flowers  with  artificial  nectar,  represented  by  honey;  (2)  that 
insects  cease  their  visits  when  one  cuts  out  the  nectary  without  injuring 
the  colored  parts,  and  re-begin  their  visits  if  one  replaces  the  destroyed  nec- 
tary by  honey;  (3)  that  it  suffices  to  attract  numerous  insects  if  one  puts 
honey  on  or  in  normally  anemophilous  flowers,  simply  green  or  brown  in 
color,  which  are  normally  practically  invisible  and  almost  never  visited  by 
insects;  and  (4)  that  the  visiting  of  flowers  artificially  made  of  fresh  green 
leaves  and  containing  honey  demonstrates  plainly  the  role  of  the  sense  of 
smell. 

It  must  be  said  that,  despite  many  just  criticisms  which  may  be  made  on 
the  character  of  his  experiments.  Plateau  has  made  necessary  more  experi- 
mentation for  the  relief  of  the  general  theory  that  floral  adaptation  of  color 
is  due  to  the  color  preferences  of  insect  visitors.  It  seems  to  me  probable 
that  the  truth  of  the  matter  is  in  a  large  degree  expressed  by  the  statement 
that  the  distant  attraction  is  exerted  by  the  odors  of  flowers  working  on  a 
very  sensitive  sense  of  smell  in  insects  (chemotropism,  in  the  language  of 
the  modern  believers  in  reflexes),  while  the  intimate  guiding  to  the  particu- 
lar flower  and  the  nectary  is  controlled  chiefly  by  the  color  and  pattern. 

Finally  we  come  to  the  question  of  the  origin  of  this  mutually  advan- 
tageous interrelation  and  its  many-branched  course  of  development  or 
speciaHzation.  Advantage  and  natural  selection  are  looked  on  as  the  chief 
factors  in  this  development.  "It  is  extremely  probable,"  says  the  botanist 
Campbell,  "that  all  the  primitive  flowers  were  anemophilous  (cross-poUi- 
nated  by  the  wind),  and  that  from  these  have  been  derived  the  more  special- 
ized entomophilous  and  ornithophilous  forms.  It  is  evidently  of  advantage 
to  the  plant  to  have  the  great  waste  of  pollen  necessitated  by  wind-pollina- 
tion reduced,  and  this  is  possible  when  insects  or  birds  are  the  agents  in  its 
transfer.  It  is  probable  that  entomophily  began  by  the  casual  visits  of 
insects  to  flowers,  attracted  by  the  pollen,  which  is  still  the  principal  object 
of  visits  by  many  insects,  serving  as  an  important  source  of  food.  Flowers 
which  had  more  conspicuous  stamens  or  perianth  would  stand  a  better  chance 
of  visits  from  insects,  and  from  the  slight  variations  thus  started  may  have 
proceeded  the  development  of  the  conspicuous  flowers  of  the  modern  ento- 
mophilous plants."  To  attract  insects  not  pollen-eaters  the  development 
of   the   nectar   has  been   necessary.     However  sweet-smelling  or  beautiful, 


582  Insects  and  Flowers 

flowers  would  not  be  visited  by  insects  unless  they  had  some  inducements 
more  substantial  to  offer.  These  inducements  are  the  pollen  and,  to  the 
great  majority  of  flower-visiting  insects,  the  nectar. 

It  is  of  distinct  interest  to  note  that  no  plants  with  colored  flower-parts 
or  special  floral  envelopes  existed  (in  geological  time)  before  the  time  of 
winged  insects.  The  oldest  fossil  Angiosperms,  monocotyledons  as  well 
as  dicotyledons,  are  from  the  lower  Cretaceous  rock  strata;  in  Tertiary  times 
there  was  a  great  increase  in  the  number  and  variety  of  the  dicotyledons, 
and  most  of  the  present  families  were  probably  in  existence  in  those  times. 
Winged  insects  are  known  from  Devonian  rocks,  and  much  more  numer- 
ously from  Carboniferous  strata;  but  all  these  early  Paleozoic  insects  belong 
to  the  lower  more  generalized  kinds,  which  to-day  take  httle  part  in  cross- 
pollination.  Not  until  Jurassic  times  did  the  higher  orders  appear,  the 
Hymenoptera,  Lepidoptera,  and  Diptera,  which  include  the  great  majority 
of  the  cross-pollinating  insect  agents.  Thus  the  insects  which  we  know  to- 
day as  the  pollen-  and  nectar-feeders,  hence  flower-visitors,  began  to  be  abun- 
dant coincidently  with  or  a  little  in  advance  of  the  flowering  plants.  Recip- 
rocally helpful  and  mutually  adapting  themselves  to  the  growing  interrela- 
tion, the  flies,  bees,  moths,  and  butterflies  on  the  animal  side  and  the 
dicotyledonous  plants  with  varied  flower-shapes,  color,  and  pattern  on  the 
vegetable  side  have  developed  so  successfully  that  in  present  times  both 
flower-visiting  insects  and  insect-attracting  flowers  have  come  to  be  the 
most  specialized  and  notable  members  of  each  of  their  respective  groups  of 
organisms. 


CHAPTER   XVII 

COLOR   AND   PATTERN   AND   THEIR   USES 

CONSPICUOUS  characteristic  of  the  insect 
body  is  its  color-pattern.  The  painted  butter- 
flies, the  great  moths,  the  burnished  beetles, 
the  flashing  dragon-flies,  the  green  katydids 
and  brown  locusts,  all  attract  attention  first 
by  the  variety  or  intensity  of  their  colors 
and  the  arrangement  of  these  colors  in  simple 
or  intricate  S3Tnmetry  of  pattern.  Even  the 
small  and,  at  casual  glance,  obscure  and 
monochrome  insects  reveal  on  careful  ex- 
amination a  large  degree  of  color  development 
and  an  ofttimes  amazing  intricacy  and  beauty  of  pattern.  So  uniformly 
well  developed  is  color-pattern  among  insects  that  no  thoughtful  collector  or 
observer  of  these  animals  escapes  the  self-put  question.  What  special  cause 
is  it  that  results  in  such  a  high  degree  of  specialization  of  color  and  its 
arrangement  throughout  the  insect  class?  and  if  he  be  an  observer  who 
has  taken  seriously  the  teachings  of  Darwin  and  the  utilitarian  school  of 
naturalists,  his  question  becomes  couched  in  the  form.  What  is  the  use  to 
the  insects  of  all  this  color  and  pattern? 

For  the  attitude  of  any  modern  student  of  Nature,  confronted  by  such 
a  phenomenon,  is  that  of  the  seeker  for  the  significance  of  the  phenomenon. 
And  the  key  to  significance  in  such  a  case  is  to  be  sought  in  utility.  The 
usefulness  of  color  in  animate  Nature  as  an  inspirer  and  satisfier  of  our 
own  aesthetic  needs  and  capacities,  or  of  color-patterns  as  means  whereby 
we  may  distinguish  and  recognize  various  sorts  of  animals  and  plants,  is  a 
usefulness  which  may  be  answer  enough  to  the  passing  poet  on  the  one  hand, 
and  the  old-line  Linnean  systematist  on  the  other,  but  is,  of  course,  no  answer 
to  science.  Science  demands  a  usefulness  to  the  color-bearing-  organisms 
themselves;  and  a  usefulness  large  and  serious  enough  to  be  the  sufficient 
cause  for  so  highly  specialized  and  amazing  a  development. 

The  explanations  of  some  of  the  color  phenomena  of  insects  are  obvious; 
some  uses  we  recognize  quickly  as  certain,  some  as  probable,  some  as  possible. 

583 


584  Color  and  Pattern  and  their  Uses 

Some  colors  are  obviously  there  simply  because  of  the  chemical  make-up 
of  parts  of  the  insect  body.  That  gold  is  yellow,  cinnabar  red,  and  certain 
copper  ores  green  or  blue  are  facts  which  lead  us  to  no  special  inquiry  after 
significance;  at  least  significance  based  on  utility.  And  if  an  insect  has 
part  of  its  body  composed  of  or  containing  a  substance  that  is  by  its  very 
chemical  and  physical  constitution  always  red  or  blue  or  green,  we  may 
be  content  with  knowing  it  and  not  be  too  insistent  in  our  demand  to  the 
insect  to  show  cause,  on  a  basis  of  utility,  for  being  partly  red  or  blue  or 
green.  And  even  if  this  red  or  blue  be  disposed  with  some  symmetry,  some 
regularity  of  repetition,  either  segmentally  or  bilaterally,  this  we  may  well 
attribute  to  the  natural  segmental  and  bilaterally  symmetrical  repetition  of 
similar  body  parts.  Some  color  and  some  color-pattern,  then,  may  be 
explicable  on  the  same  basis  as  the  color  of  a  mineral  specimen  or  of  a  tier 
of  bricks. 

But  no  such  explanation  will  for  a  moment  satisfy  us  as  to  the  presence 
and  arrangement  of  colors  in  the  wing  of  Kallima,  the  dead-leaf  butterfly 
(PL  XIII,  Fig.  i),  or  in  Phyllium,  the  green-leaf  Phasmid  (PI.  XIII,  Fig.  2). 
We  demand  an  explanation  based  on  direct  and  large  usefulness  to  the  insect. 

Certain  uses  seem  pretty  apparent:  the  brown  and  blackish  pigments 
in  the  compound  eyes  have  the  function  of  absorbing  light-rays  so  that  these 
rays  may  be  prevented  from  passing  through  the  walls  of  adjacent  ommatidia, 
and  thus  confusing  the  mosaic  vision;  the  pigment  of  the  simple  eye-flecks 
of  some  insect  larvae  serves,  as  in  the  eye-spots  of  other  simple  animals,  to 
absorb  light  at  a  certain  spot  especially  sensitive  and  thus  make  possible 
a  recognition  of  light  intensity,  a  low  grade,  not  of  seeing,  but  of  simple  appre- 
ciation of  the  presence  or  absence  of  light.  Some  color  in  the  skin  of  insects 
may  serve,  too,  as  is  pretty  certainly  the  case  with  many  vertebrates,  to 
absorb  heat  or  prevent  its  radiation,  or,  on  the  other  hand,  to  reflect  it,  or 
to  allow  it  to  radiate  freely.  In  view  of  the  cold-bloodedness  of  insects  this 
must  be  a  use,  in  this  class  of  animals,  extremely  restricted  and  infrequent. 
But  such  uses  as  these  are  at  best  explanatory  of  but  little  of  the  wealth  of 
color  and  pattern  manifest  in  the  insect  class.  A  utility  more  important, 
and  common  to  many  more  individuals  and  capable  of  explaining  a  specializa- 
tion of  color  and  pattern  much  more  complex,  is  needed  as  a  basis  for  color 
significance. 

The  green  katydid  singing  in  the  tree-top  or  shubbery  is  readily  known 
to  be  there  by  its  music,  but  just  which  bit  of  green  that  we  see  is  katydid 
and  which  is  leaf  is  a  matter  to  be  decided  by  unusually  discriminating  eyes. 
The  clacking  locust,  beating  its  black  wings  in  the  air,  is  conspicuous  enough, 
but  after  it  has  alighted  on  the  ground  it  is  invisible,  or,  rather,  visible  but 
indistinguishable;  its  gray  and  brovm  mottled  color-pattern  is  simply  con- 
tinuous with  that  of  the  soil.     The  green  larva;  of  the  Pierid  butterflies 


PLATE  XIII. 
PROTECTIVE    RESEMBLANCE. 

1.  Kallima  scj. 

2.  Phyllium  scj. 

3.  4,  5.     Larvae  of  Lyciena  sq.  on  California  buckeye,  /Esculus  californicus. 


PLATE    XIII 


Color  and  Pattern  and  their  Uses  585 

lying  longitudinally  along  green  grasses  simply  merge  into  the  color  scheme 
of  their  environment.  The  gray  moth  rests  unperceived  on  the  bark  of 
the  tree-trunk.  Hosts  of  insect  kinds  do  really  thoroughly  harmonize  with 
the  color-pattern  of  their  usual  environment,  and  by  this  correspondence 
in  shade  and  marking  are  difficult  to  perceive  for  what  they  are.  Now 
if  the  eyes  that  survey  the  green  foliage  or  run  over  the  gray  bark  are  those 
of  a  preying  bird,  lizard,  or  other  enemy  of  the  insect,  it  is  quite  certain — 
our  reason  tells  us  so  insistently — that  this  possession  by  the  insect  of  color 
and  pattern  tending  to  make  it  indistinguishable  from  its  immediate  environ- 
ment is  advantageous  to  it:  advantageous  to  the  degree  of  often  saving  its 
life.  Now  such  a  use  of  color  and  pattern  is  obviously  one  which  can  be 
wide-spread  through  the  insect  class,  and  may  be  to  many  species  which 
lead  lives  exposed  to  the  attacks  of  insectivorous  animals  of  large — even 
of  life  and  death — importance.  And  naturalists,  most  of  them  at  least, 
believe  that  th's  kind  of  usefulness  is  real,  and  that  it  is  the  principal  clue 
to  the  chief  significance  of  color  and  pattern.  And  this  not  alone  in  the 
case  of  insects,  but  of  most  other  animals  as  well. 

From  this  point  of  view,  namely,  that  color-patterns  may  be  of  advantage 
in  the  struggle  for  existence,  just  as  strength,  swiftness,  and  other  capacities 
and  conditions  are,  the  specialization  and  refinement,  all  the  wide  modifica- 
tion and  variety  of  colors  and  patterns,  are  explicable  by  the  hypothesis  of 
their  gradual  development  in  time  through  the  natural  selection  of  naturally 
occurring  advantageous  variations.  On  this  basis,  such  special  instances 
of  resemblance  to  particular  parts  of  the  environment,  as  that  shown  by 
Kallima  in  its  likeness  to  a  dead  leaf,  and  Diapheromera  in  its  simulation 
of  a  dry,  leafless  twig,  are  simply  the  logical  extremes  of  such  a  line  of  speciali- 
zation. 

But  the  nature  observer  may  be  inclined  to  ask  how  such  brilliant  and 
bizarre  color-patterns  as  those  of  the  swallowtail-butterflies  and  the  tiger- 
banded  caterpillars  of  Anosia  can  be  included  in  any  category  of  "protective 
resemblance"  patterns.  They  are  not  so  included,  but  are  explained  inge- 
niously by  an  added  hypothesis  called  that  of  "warning  colors,"  while  for 
the  striking  similarities  of  pattern  often  noted  between  two  unrelated  con- 
spicuously colored  species  still  another  clever  hypothesis  is  proposed.  In 
these  cases  it  is  not  concealment  that  the  color-pattern  effects,  but  indeed 
just  the  opposite.  Since  the  pioneer  studies  of  Bates  and  Wallace  and  Belt, 
naturalists  have  been  observing  and  experimenting  and  pondering  these 
exposing  as  well  as  these  concealing  conditions  of  color  and  pattern,  and 
they  have  proposed  several  theories  or  hypotheses  explanatory  of  the  various 
conditions.  These  hypotheses  are  plausible ;  but  they  are  much  more  than 
that;  they  are  each  more  or  less  well  backed  up  by  observation  and  experi- 
ment, and  some  of  them  have  gained  a  large  acceptance  among  naturalists. 


586  Color  and  Pattern  and  their  Uses 

Both  the  reasoning  and  the  observed  facts  on  which  these  hypotheses  rest 
are  based  on  the  usefulness  of  the  colors  and  patterns  to  the  animals  in  their 
relation  to  the  outside  world.  And  the  influence  of  advantage  and  natural 
selection  is  given  the  chief  credit  for  determining  the  present-day  conditions 
of  these  colors  and  patterns. 

Before,  however,  we  take  up  these  hypotheses,  defining  them  and  looking 
over  some  of  the  evidence  adduced  for  their  support,  as  well  as  some  of  the 
criticism  leveled  at  them,  we  may  advisedly  look  to  the  actual  physical  causa- 
tion of  color  in  insects.  Whatever  the  use  or  significance  of  color,  our 
understanding  of  this  use  must  be  based  on  a  knowledge  of  the  method  or 
modes  of  the  actual  production  of  color. 

Color  in  organisms  is  produced  as  color  in  inorganic  Nature  is.  Certain 
substances  have  the  capacity  of  selective  absorption  of  light-rays  so  that 
when  white  light  falls  on  them,  certain  colors  (light-waves  of  certain  length) 
are  absorbed,  while  certain  others  (light-waves  of  certain  other  lengths)  are 
reflected.  An  object  is  red  because  the  substance  of  which  it  is  (superficially) 
composed  reflects  the  red  rays  and  absorbs  the  others.  Certain  other  objects 
or  substances  may  produce  color  (be  colored)  because  of  their  physical  rather 
than  their  chemical  constitution:  their  surfaces  may  be  so  composed  ol 
superposed  lamellae,  or  so  striated  or  scaled,  that  the  various  component 
rays  of  white  light  are  reflected,  refracted,  and  diffracted  in  such  varying 
manner  (at  different  angles  and  from  different  depths)  that  complex  inter- 
ference effects  are  produced,  resulting  in  the' practical  extinguishing  of  cer- 
tain colors  (waves  of  certain  length),  or  the  reflection  of  some  at  angles  so 
as  not  to  fall  on  the  eye  of  the  observer,  and  so  on.  Such  colors  will  change 
with  changes  in  the  angle  of  observation,  and  are  the  so-called  metallic  or 
iridescent  colors.  These  two  categories  of  color  have  been  aptly  called 
chemical  and  physical:  chemical  color  depending  on  the  chemical  make-up 
of  the  body,  physical  on  its  structural  or  physical  make-up.  As  a  matter 
of  fact  we  shall  find  that  most  insect  colors  are  due  to  a  combination  of  these 
two  kinds. 

Substances  that  produce  color  by  virtue  of  their  capacity  to  absorb  certain 
colors  and  reflect  only  one  or  more  others  we  may  call,  in  our  discussion  of 
color  production,  pigments,  and  pigmental  may  be  used  as  practically  synony- 
mous with  chemical  in  referring  to  colors  thus  produced,  while  structural 
may  be  sometimes  used  as  synonymous  with  physical  in  referring  to  colors 
dependent  on  superficial  structural  character  of  the  insect  body.  For  colors 
produced  by  the  co-operation  of  both  pigment  and  structure,  combination 
or  chemico-physical  may  be  used  as  a  defining  name.  In  a  recent  valuable 
paper  by  Tower  *  the  history  of  and  authority  for  the  adoption  of  these 
various  names  is  given. 

*  Tower,  W.  L.  Colors  and  Color-patterns  of  Coleoptera.  Decennial  Pubs,  of 
Univ.  of   Chicago,  1903,  vol.  X,  pp.  33-70. 


Color  and  Pattern  and  tlieir  Uses  587 

Tower  finds,  on  the  basis  of  his  own  researches  and  those  of  various  other 
investigators  of  insect  colors,  that  among  insects  the  chemical  colors  are 
yellow,  orange,  red,  buff,  brown,  black,  and  rarely  green-blue  and  black; 
physical  colors  are  the  pearly  colors,  almost  all  whites,  and  rarely  violet- 
greens,  reds,  and  some  metallic  and  iridescent  colors;  while  chemico-physical 
colors  are  violet,  greens,  reds,  and  iridescent  and  almost  all  metallic  colors. 
Tower  believes  it  probable  that  but  few  really  pure  physical  colors  will  be 
found  in  insects,  by  far  the  larger  part  of  those  now  classed  as  such  falling 
into  the  category  of  the  chemico-physical.  Tower  finds  white  to  be  the 
only  purely  physical  color  occurring  among  the  Coleoptera  (the  insect  group 
whose  colors  he  has  specially  studied). 

With  regard  to  the  situation  of  the  pigments  on  which  chemical  and, 
partly,  physico-chem  cal  colors  depend,  these  colors  may  be  divided  into 
cuticular  and  hypodermal  (first  defined  by  Hagen)  and  subhypodermal 
(defined  by  Tower).  The  cuticular  colors  are  produced  by  coloring  sub- 
stances situated  in  the  chitinized  cuticle  that  overlies  the  whole  insect  body; 
they  are  permanent  colors,  not  fading  after  death,  and  are  insoluble,  without 
actual  dissolution  of  the  cuticle,  in  water,  acids,  alkalies,  ether,  or  essential 
oils;  they  are  browns,  blackish,  drab,  some  yellows,  and  possibly  some  reds. 
The  hypodermal  colors  are  produced  by  pigments  lying  in  the  hypoderm 
(cellular  layer  of  the  skin,  just  underneath  the  cuticle)  and  are  of  two  sub- 
categories, viz.,  first  some  yellows  and  green  which  are  due  to  xyanthophyll 
and  chlorophyll  taken  from  plant-food,  and  which  are  not  permanent, 
fading  after  death  and  on  exposure,  and  soluble  in  the  usual  organic 
solvents;  and  second,  certain  permanent  colors,  reds  and  chrome  yellows, 
due  to  definite  pigment  granules  imbedded  in  the  cytoplasm  of  the  hypo- 
dermal cells.  The  subhypodermal  colors,  found  practically  only  in  larvae, 
are  due  to  various  substances,  as  derived  plant  pigments  and  others, 
in  the  haemolymph  (blood)  which  show  through  the  skin  (hypoderm  and 
cuticle). 

The  structural  or  physical  colors,  and  the  combination  or  physico-chemical 
colors,  to  which  two  classes  belong  all  white  and  all  metallic,  pearly  and 
iridescent  colors,  including  most  blues,  greens,  violet,  and  golden,  depend 
for  their  production  on  a  superficial  or  surface  structural  condition  of  the 
insect  body  or  part  consisting  either  of  the  superposition  of  one  or  more 
thin  transparent  or  translucent  lamellje  over  a  darker  layer,  or  the  fine 
roughening  of  the  surface  by  means  of  striae,  pits,  or  minute  hair-like  processes. 
Tower  has  offered  a  graphic  classification  of  these  colors  (together  with  the 
one  already  explained  of  chemical  colors)  in  the  table  which  follows.  The 
classification  is  sufficiently  explained  in  the  table  to  make  unnecessary  any 
further  discussion  of  the  various  kinds  of  structures  involved  in  color  pro- 
duction among  insects. 


588 


Color  and  Pattern  and  their  Uses 


TABLE  OF  INSECT  COLORS. 


By  W,  L.  Tower. 


Chemical 
colors 


f  Black 
Cuticular  I  Dark  brown 
colors        I  Brown 

{_  Straw  yellows 


Located 


primary 
cuticula 


Permanent.     Insoluble     in     water, 

alcohol,   ether,   oils,   weak   acids, 

or  alkalies 
Soluble     in      strong      concentrated 

mineral  acids  with  dissolution  of 

the  cuticula 


Hypodermal 
colors 


Chrome 

yellows 
Red 

Vermilion 
Scarlet 
Blue 


Located  in 

hypodermal 

cells  as 

granules 


•J    I 


Green 

Yellow 

White 


Located  in 
or  between 
the  hypo- 
dermal 
cells 


Sub- 
hypodermal 
colors 


Green 

Yellow 

White 


Located  in 
the  body- 
cavity  in 
hsemolymph 
or  fat-body 


Derived 
pigments 


Derived 
pigments 


Permanent.  Insoluble 
in  water,  oils,  alcohol, 
weak  acids,  or  alkalies 

Soluble  in  ether  or  other 
fatty  solvents 

Not  permanent. 
Fade  at  death  or 
on  exposure 

Soluble  in  water,  al- 
cohol, etc. 

Are  chlorophyll  or 
xyanthophyll  de- 
rivatives largely 

Not  permanent.  Fade 
at  death  or  on  e.x- 
posure 

Soluble  in  usual  or- 
ganic solvents 


'  Reflection 
colors 


Physical 
colors 


White 


)  Caused  by  air  included  within  scales,  etc._     The  most 
j      common,  and  perhaps  the  only  true  physical,  color 


Refraction   I   MetalUc     I    Opalescent 
colors  I     colors        I     colors 


Caused  by  combining  white  and 
some  metaUic  refraction  color, 
usually  with  pigment  present. 
Frequently  caused  by  thin  irregu- 
lar lamellae  over  pigment,  giving 
effect  of  Newton's  rings 


Diffraction   j  Iridescent  I  gee  next  class 
colors  I    colors        ) 


Chemico- 
physical 
colors 


Reflection  Colored  surfaces 
pigmental  >  with  polished  ap- 
colors  (a)        pcarance 


Blacks 
Browns 
Yellows 
Reds 


Caused  by  a  polished  lamellar 
surface  over  layer  of  pig- 
ment. 


Refraction    i  Almost  all 
pigmental  -|    metallic 
colors  {b)    (    colors 


Cause— polished    refractive    lamella    overlying    a 
layer  of  pigment 


Diffraction   (  Alniost  all   |  Cause— surface  structures,  pits,  ridges  on  refrac- 
pigmental  -l    iridescent   V      ^j^^  lamella  overiving  a  layer  of  pigment 
colors  (c)    (    colors  ) 


Combination 
colors 


Various  iridescent  metalUc  and 
opalescent  metallic  colors,  etc., 
in  which  colors  of  groups  a,  b, 
and  c  combine  to  produce  color 
effects 


This  class  of  color  is  con- 
fined largely  to  Lepi- 
doptera  and  almost  ex- 
clusively to  scaled  in- 
sects or  areas  bearing 
scales 


Color  and  Pattern  and  their  Uses 


5^9 


That  our  discussion  of  insect  colors  may  be  made  more  explicit  we  may, 
with  the  foregoing  account  of  the  causes  and  kinds  of  colors  in  mind, 
endeavor  to  see  just  how  the  color-pattern  of  a  certain  single  group  of  insects 
is  produced.  This  group  is  that  of  the  moths  and  butterflies,  in  which 
color  and  pattern  obviously  reach  a  maximum  of  development  and  special- 
ization. 

If  the  wing  of  a  moth  or  butterfly  be  rubbed  gently  between  finger  and 
thumb,  a  spot  on  the  wing  will  soon  lose  its  color  and  become  transparent, 
while  on  finger  and  thumb  will  be  found  a  fine  sparkling  powder,  the  "flour" 
of  the  miller-moth,  the  jewel-dust  of  the  butterfly.  This  dust,  rubbed  on 
a  glass  slide  and  examined  under  the  microscope,  will  be  seen  to  be  com- 


FiG.  770. — Single  scale  from  moths  and  butterflies,     a,  from  Tolype  velleda;  h,  from  Casl- 
nia  sp.;   c,  from  Micropteryx  aruncella.     (Greatly  magnified.) 


posed  of  symmetrical  tiny  scales,  each  composed  of  a  flattened  blade  and 
short  stem  or  pedicel  (Fig.  770).  A  considerable  variety  of  shape  will  be 
noticeable  among  these  scales,  and  if  scales  are  rubbed  from  other  moths 
and  butterflies,  many  new  shapes  will  be  found.  But  through  all  this  diver- 
sity of  appearance,  a  fundamental  plan  of  make-up 
may  be  recognized  in  each  of  these  minute  structures. 
Most  commonly  the  scales  are  more  or  less  ovate  in 
outline  with  the  little  stem  projecting  from  the  narrower 
end.  The  broader  end  has  its  margin  entire  or  with 
dentations  of  varying  depth  and  number.  These  den- 
tations may  be  so  deep  that  the  scale  looks  like  a 
several-fingered  little  hand.  In  size  the  scales  vary 
from  .07  mm.  {^^-^  inch)  to  .8  mm.  {-^^  inch)  if  we  Fig.  771.— Scale  of 
exclude  the  long  hair-like  forms  common  near  the  base  epta  us    meg  as  i- 

o  am,     snowing      pn- 

of    each    wing,    and    also    the    slender    elongate    ones       mary  and  secondary 

which  project    from  the  wing-margins.      In  width  the       stnation.     (Greatly 

^      •'  a  !D  magnmed.) 

scales  vary  from  hair-like  to  a  breadth  of  .4  mm.  (^^^  inch). 

Some  scales  are  as  broad  as  long,  or  even  broader  than  long.      Running 

longitudinally  from  base  to  outer  margin  are  many  fine  little  subparallel 


590 


Color  and  Pattern  and  their  Uses 


lines  or  striae.  These  striae  vary  in  distance  apart,  on  different  scales,  from 
.0007  mm.,  as  in  the  scales  of  the  great  blue  Morpho  butterflies,  to  .004  mm., 
as  in  the  sulphur-yellow  butterfly,  Catopsila  eubide. 

The  scales  cover  (in  all  but  the  few  "  clear- winged "  moths)  the  wings 

on  both  upper  and  lower  sides, 
being  insecurely  attached  to  the 
wing  membrane  by  having  their 
short  pedicels  inserted  in  little 
pockets  or  cups  on  the  wing  sur- 
face. They  show  an  interesting 
and  varying  manner  of  arrangement. 
This  arrangement  varies  from  an 
extremely  uniform  one  in  the  but- 
terflies and  higher  moths  to  one 
of  much  less  regularity  of  disposi- 
tion in  the  lower  moths-.  On  the 
wings  of  a  butterfly  the  scales  are 
inserted  with  their  pedicels  directed 

„  ,         „  ,      ,       ,   ,  r  toward   the   base   of   the   wing    in 

I'IG.  772. — A  small,    partly    denuded   part  01  ,  ° 

the  wing  of  a  butterfly,  Lyceita  sp.,  showing  subparallel  rows  runnmg  trans- 
the  scales  and  pits  in  a  wing  membrane,  versely  across  the  wing,  i.e.,  from 
into  which  the  tiny  stems  of  the  scales  are         ^      .        ^  ^     .  .  , 

inserted.  (Photomicrograph  by  George  O.  anterior  to  posterior  margin,  and 
Mitchell;  greatly  magnified.)  the    scales    in    each    row    are    at 

approximately  equal  distances  apart.     Their  distance   is  less  than  the  width 

of    each    scale,   so    that    adjoining    scales 

overlap  laterally  and  thus  make  each  row 

to  be  composed  of  two  tiers  of  scales,  an 

upper  and  an  under  one:  the  insertion- 
cups  of  one  tier  are  very  slightly  but  per- 
ceptibly   advanced    beyond    those    of    the 

other  tier.     The   scales  of   the  upper  tier 

alternate  with  those  of  the  lower  tier,  and 

each  upper    scale    overlaps    laterally   two 

under    ones.       But    in     addition    to    this 

lateral  overlapping,  the   distance  between 

the    rows    of    insertion-cups  is  less    than 

the  length    of    the   scales,   so    that    there 

is    an    overlapping     of    the    tip    of    the 

scales  of  one    row  over  the   bases  of   the 

scales  in  the  next  row  in  front.     By  this 

double  overlapping  there  is  formed  a  complete  shingled  covering  of  scales 

over  each  surface  (upper  and  under)  of  each  wing. 


Fig.  773. — Bits  of  denuded  wing  of  a 
butterfly,  Grapta  sp.,  to  show  rows 
of  insertion-pits  on  upper  and  lower 
sides,  with  three  scales  in  position. 
(Greatly  magnified.) 


Color  and  Pattern  and  their  Uses  591 

This  close  placing  and  overlapping,  and  the  small  size  of  the  scales, 
bring  it  about  that  the  number  of  scales  on  a  single  wing  is  truly  prodigious. 


Fig.  774. — Diagram  to  show  shingled  arrangement  of  scales  over  surface  of  butterfly's 
wing;  the  short  black  bars  indicate  scales  in  cross-section;  the  broad  central  bar, 
the  wing  in  cross-section. 


In  Morpho  sp.,  for  example,  the  distance  apart  of  the  lines  of  insertion-pits 
on  a  bit  of  the  upper  wing  surface  taken  from  the  middle  of  the  fore  wing 
is  .151  mm.;  the  distance  apart  of  the  pits  in  a  line  is  .043  mm.  (on  the 
under  surface  the  pits  are  .05  mm.  apart);  so  that  in  a  space  25  mm.  by 
25  mm.  (i  square  inch  circa)  there  would  be  165  lines  of  scales  with  600  scales 
in  each  line,  or  99,000  scales  to  each  square  inch  of  wing-surface.  As  the 
upper  and  under  surfaces  of  the  fore  and  hind  wings  combined  equal  about 
15  square  inches,  the  total  number  of  scales  on  the  wings  of  Morpho  may 
be  roughly  approximated  at  1,500,000. 

The  pedicels  of  the  scales  are  of  slightly  varying  shapes  and  of  different 
lengths,  corresponding  with  the  pockets  into  which  they  fit.  Those  which 
enter  insertion-cups  which  are  expanded  at  the  base,  or  at  some  point  between 
the  base  and  the  mouth,  present  at  the  tip  or  be- 
tween the  tip  and  the  point  of  merging  into  the 
blade  of  the  scale,  respectively,  a  slight  expan- 
sion, so  that  they  are  pretty  firmly  held  in  the  cup 
by  a  sort  of  ball-and-socket  attachment.  The 
scales  are  held  in  position  by  the  elasticity  of 
the  cups  which  closely  clasp  the  pedicels.      After 

death  of  the  moth  or  butterfly  this  elasticity  is 

1  1       1     i     T.       J     •        i.'  r    xi  •  Fig.  77=;. — Base  of  scales:    a, 

largely   lost,   by   desiccation   of   the  wmg   mem-      ^f  ^^;^^,,,^.^  arizonesis;  h,  of 

brane,  and  the  pedicels  are  more  easily  brushed  Morpho  sp.  (Greatly  mag- 
from  the  wing  than  when  the  insect  is  alive.  mfaed.) 

Now  to  pay  attention  to  the  actual  structure  or  make-up  of  individual 
scales.  When  studied  carefully  under  the  microscope  singly  and  in  cross- 
sections  of  the  wing  the  scales  are  seen  to  be  tiny  flattened  sacs,  composed 
of  two  membrances,  enclosing  sometimes  only  air,  sometimes  pigment 
granules  attached  to  the  inner  face  of  one  of  the  membranes,  and  some- 
times (as  observed  in  cabinet  specimens)  the  dry  remains  of  what  may  have 
been  during  life  an  internal  pulp.  The  striae  are  confined  to  the  outer  mem- 
brane (that  farthest  from  the  wing-membrane)  and  are  probably  folds  in 
this  outer  membrane.      These  striae    are  plainly  elevated   above  the  inter- 


592 


Color  and  Pattern  and  their  Uses 


strial  space.  All  scales,  excepting  some  androconia  (scent-scales  on  male 
butterflies)  (Fig.  777),  possess  these  longitudinal  stride,  which  traverse  the  scale 
from  base  to  outer  margin  and  are  very  sharp,  and  sepa- 
rated from  one  another  by  equal  distances.  The  stride 
sometimes  curve  in  at  the  lower  angles  of  the  blade,  con- 
verging toward  the  origin  of  the  pedicel;  in  other  cases 
they  fade  out  at  these  angles.  In  scales  of  Anosio- 
plexippus  from  33  to  46  striae,  averaging  .002  mm.  apart, 
are  present  on  each  scale.  There  would  thus  be  12,500 
of  these  striae  to  the  inch.  On  transparent  scales  from 
Morpho  sp.  the  striae  were  .0015  mm.  to  .002  mm.  apart; 
on  opaque   (pigment-bearing)   scales  from  the  same   spec- 

FiG.    776. Scale   imen    the    striae    were    from   .0007    to    .00072    mm.    apart, 

of  Lycomorpha  or  at  the  rate  of  about  35,000  to  the  inch. 

constans,  show-  ^.  .  ,  •         t         -i        \        ^     j     a  c 

ins  cross-stricc.         ^^  ^^'^  examme  a  long  series  01  scales  brushed  on  from 

(Greatly   mag-  different    parts    of   a  wing  of  moth   or   butterfly,   we    can 
always  note  a  series  of  gradating  forms  running  from  slender 

The  significance  of  this, 


nified.) 


hair-like  form  to  typical  short,  broad,  flat  scale, 
when  we  come  to  inquire  about  the  origin 
of  scales,  is  plain.  Scales  are  unusual  struc- 
tures among  insects:  besides  the  moths  and 
butterflies,  only  a  few  beetles,  the  mosquitoes, 
the  fish -moths,  and  a  few  other  scattering  insects 
have  them.  But  all  insects  have  hairs.  Hairs 
are  structures  common  throughout  the  class. 
And  it  is  certain  that  scales  are  derived  or  de- 
veloped from  hairs.  They  are  a  specialized,  a 
highly  modified  sort  of  hair.  On  the  lower,  the  a 
more  generalized  moths,  the  hair-like  scales  are 
the  more  abundant.  The  wings  show  a  thick 
intermixing  of  loose,  fluffy  hair-scales  or  scale- 
hairs  with  more  typical  scales  irregularly  ar- 
ranged. In  the  higher  Lepidoptera,  the  spe- 
cialized sort  of  hairs,  namely  the  scales,  com- 
pose almost  exclusively  the  wing-covering,  and 
these  scales  are  arranged  in  the  specialized  -pio 
uniform  shingling  manner  previously  described. 
But  even  on  the  wings  of  a  butterfly  all  the 
gradations  from  hair  to  scale  can  be  found  by 
going  from  base  out  to  discal  area  of  the  wing. 
These  gradation  series  vary  in  character  in  dif- 
ferent families,  as  shown  in  Figs.   778,  779,  780,  and   781 


777.  Androconia  from 
wings  of  male  butterflies,  a, 
from  wing  of  Nymphalid 
butterfly;  h,  from  wing  of 
Pierid  butterfly;  c,  from 
wing  of  I-yca>nid  butterfly. 
(All  greatly  magnified.) 


In   some  the 


Color  and  Pattern  and  their  Uses 


593 


hair    becomes    a    scale    by   shortening  and    broadening,  keeping    its    free 
tip  entire;    in  others  the  hair  splits  distally  and  then  each   branch    splits 


YiG,  778.— Scales  taken  from  a  single  fore  wing  of  Megalopyge  crispata,  showing  grada- 
tions from  true  hair  to  specialized  scale.     (Greatly  magnified.) 

again,  and  so  on,  while  the  base  is  continually  shortening  and  broadening 
so   that    the    scale   form    finally  reached    is   a  fingered   or  deeply-toothed 


Fig.  779. — Scales  from  a  single  fore  wing  of  Gloveria  arizonesis,  showing  gradations  from 
scale-hair  to  speciahzed  hair.     (Greatly  magnified.) 

one.  But  in  all  the  series  the  final  result  is  that  from  a  long,  slender,  sub- 
cylindrical  hair  is  evolved  a  short,  broad,  flattened,  little  scale.  A  study 
of  the  actual  development  of  an  individual  scale  on  the  forming  wing  of  a 
butterfly  during  the  pupal  or  chrysalid  stage  confirms  the  hypothesis  of  the 
evolution  of  the  scales.  In  the  growing  developing  wing  the  scales  begin 
as  hairs,  arising  by  the  extension  of  certain  hypodermal  cells  in  the  wing- 


594 


Color  and  Pattern  and  their  Uses 


membrane  which  gradually  change  in  the  few  or  many  days  of  pupal  develop- 
ment into  typical  scales  (Figs.  782  and  783). 


Fig.  780. — Scales  from  a  single  fore  wing  of  Heliconia  sp.,  showing  gradations  from  scale- 
hair  to  specialized  scale.     (Greatly  magnified.) 

We  have  studied  now  with  some  care  the  general  character  of  the  scale- 
covering  of  moths  and  butterflies,  and  the  actual  structural  make-up  and 

the  origin  of  the  indi- 
vidual scales.  And  we 
learned  at  the  very  begin- 
ning of  our  study  that 
it  is  the  scale  -  covering 
which  is  the  producer  or 
carrier  of  all  the  brilliant 
and  varied  color  and 
pattern  which  character- 
ize the  moths  and  butter- 
flies. When  we  rub  off 
the  myriad  little  scales 
the  wings  themselves  are 
found  to  be  colorless,  transparent.  We  have  now  to  note  how  it  is  that 
the  scales,  the  color-carrying  organs,  actually  produce  the  colors. 

The  scales  in  their  fully 
developed  dry  condition  are 
chiefly  cuticular  in  structure, 
but  they  may  contain  pig- 
ment granules  and  various 
substances  left  by  the  hypo- 
dermal  cell-layer  in  drying. 
The  colors  of  the  scales  are 
to  be  classified  then  as  both 
cuticular  and  hypodermal  in 
character,  and  both  chemical 
and  physical  in  origin.  For 
the  most  part  they  are  strictly 
combination    colors    due    to 


Fig.  781. — Scales  from  a  single  hind  wing  of  the 
goat-moth,  Prionoxystus  robincE,  showing  gra- 
dations from  scale-hair  to  specialized  scale. 
(Greatly  magnified.) 


Fig.  782. — Diagrammatic  figures  showing  the  devel- 
opment of  the  scales  on  a  wing  of  Euvanessa  anti- 
opa;  at  left,  cross-section  of  bit  of  pupal  wing  show- 
ing the  two  wing-membranes  and  intervening  space 
or  wing-cavity;  at  right,  cross-section  of  a  single 
wing-membrane  in  older  pupal  wing.  5.C.,  scale- 
cells;  /i^"/).,  hypodermal  cells;  /.leucocytes;  5,  devel- 
oping scales.     (After  Mayer;    greatly  magnified.) 


Color  and  Pattern  and  their  Uses 


595 


chemical  (pigmental)  substances  within  the  scale  and  to  the  structural 
character  of  the  scale-walls.  The  pigment  granules  within  the  scales  are 
brown,  yellowish,  or  reddish,  and  as  they  mostly  transmit  the  same  colors  as 
they  reflect,  the  colors  of  strongly  pigmented  scales  are  the  same  by  trans- 
mitted light  (light  shining  through   them)  as   by  reflected  light.     But  with 


Fig.  783. — Diagrammatic  figures  showing  late  stages  in  development  of  scales  of  the 
wing  of  Anosia  plexippus;  figure  at  right  showing  older  stage  than  figure  at  left,  s, 
scale;    sc,  scale-cell;   /,  leucocyte.     (After  Mayer;    greatly  magnified.) 


the  physical  colors  this  is  not  the  case.  Scales  which  produce  brilliant 
blues  and  other  colors  are  often  empty,  and  these  when  viewed  by  trans- 
mitted light  are  nearly  colorless.  Or  they  may  contain  pigment  and  then 
when  viewed  by  transmitted  light  show  a  dull  brownish  or  yellowish  color 
entirely  different  from  the  metallic  iridescence  which  they  show  by  reflected 
light. 

The  physical  color  effects  produced  by  scales  are  due  to  their  (a)  lamina- 
tion and  (b)  striation.  Each  scale  is  composed  of  a  pair  of  thin  subtrans- 
parent  laminae  (lamellae),  the  thin  dry  sides  of  the  flattened  sac,  and  when 
arranged  in  the  shingling  sheath  over  the  wing-membrane,  overlapping 
each  other  at  sides  and  ends,  they  produce  a  layer  of  superposed  thin  trans- 
parent lamellae  which  is  exactly  the  structural  condition  necessary  to  the 
production  of  varied  refraction  (interference)  effects  of  color.  This  scale 
layer  produces  color  by  virtue  of  its  structure  just  as  a  piece  of  laminated 
mxa  or  bit  of  old  weathered  glass  or  film  of  soap-bubble  produces  color 
(Newton's  rings).  In  addition  the  striae-bearing  outer  surface  of  each  scale 
is  essentially  the  same  as  a  ruled  surface  or  grating,  producing  color  by 
diffraction  and  interference  just  as  do  the  well-known  Rowland's  and  Ruther- 
ford's gratings,  familiar  to  students  in  physical  laboratories.  In  the  finest 
of  these  artificially  striated  gratings  the  lines  are  about  .0006  mm.  apart: 
in  butterfly  scales  the  striae  are  from  .002  to  .0007  mm.  apart. 


59^  Color  and  Pattern  and  their  Uses 

The  blacks,  browns,  yellows,  and  dull  reds  of  butterflies  and  moths, 
then,  are  produced  chiefly  by  pigment;  while  all  the  brilliant  metallic  colors, 
the  iridescent  blues  and  greens,  and  hosts  of  allied  shades,  are  due  to  the 
structural  or  physical  make-up  of  the  scale-covering.  The  patterns,  varied 
and  intricate,  with  lines  and  spots  and  bars,  sharply  deliminated  or  softly 
merging  into  the  ground  color  or  into  one  another,  depend  on  the  fact  that 
the  color-units,  the  scales,  are  so  small  that  by  the  juxtaposition  of  scales 
containing  different  pigments,  or  varying  slightly  in  structure,  different 
colors  may  be  produced  abruptly  or  gradually,  depending  upon  the  degree  of 
differences  in  pigment  and  structure  of  adjacent  scales.  By  the  extremely 
regular  arrangement,  in  the  higher  moths  and  butterflies,  of  the  short,  rigid, 
little  scales,  definite  lines  and  sharp  limits  to  spots  and  bars  are  possible. 
In  the  lower,  fluffy  moths  where  the  scales  are  hair-like  and  irregularly  ar- 
ranged such  sharp  delimitations  of  pattern  parts  are  not  possible.  Thus 
the  specialization  of  the  scales,  both  as  to  structure  and  arrangement,  in 
the  brilliantly  colored  and  complexly  patterned  day-flying  Lepidoptera  is 
seen  to  be  exactly  connected  with  the  specialization  of  color  and  pattern. 

The  studies  that  have  so  far  been  made  upon  the  character  and  origin 
of  types  of  pattern  have  brought  some  aspect  of  orderliness  into  what  seems 
at  first  glance  a  chaos  of  complexity,  but  our  knowledge  of  this  matter  is 
yet  too  little  organized  to  make  it  available  in  such  a  brief  general  account 
of  insect  color  and  pattern  as  this  one  necessarily  is.     In  the  actual  develop- 


FiG.  784. — Diagrammatic    series    showing  development  of  color-pattern  in  pupal  wings 
of  the  monarch  butterfly,  Anosia  plexippiis.     (After  Mayer;   one-half  natural  size.) 

ment  or  course  of  appearance  of  the  color-pattern  in  the  wings  of  any  individual 
moth  or  butterfly  certain  conditions  regularly  obtain,  as  shown  by  Van  Bem- 
meln,  Urech,  Haase,  Mayer,  and  others.  Mayer's  account  and  figures  of 
the  development  of  color  in  the  fore  wings  of  the  monarch  butterfly,  zl«05m 
plexippHS,  show  a  typical  case.  The  pupal  stage  of  Anosia  lasts  from  one 
to  two  weeks.  "For  the  first  few  days,"  says  Mayer,  "the  wings  are  perfectly 
transparent,  but  about  five  days  before  the  butterfly  issues  they  become  pure 
white.     An  examination  of  the  scales  at  this  period  shows  that  they  are 


Color  and  Pattern  and  their  Uses 


597 


completely  formed  and  merely  lack  pigment.  In  about  forty-eight  hours 
after  this  (see  Fig.  784,  a)  the  ground-color  of  the  wings  changes  to  a  dirty 
yellow.  It  is  interesting  to  note  that  the  white  spots  which  adorn  the  mature 
wings  remain  pure  white.  Fig.  784,  b,  illustrates  the  next  stage,  where  the 
black  has  begun  to  appear  in  the  region  beyond  the  cell.     The  nervures 


Fig.  78:;. — Diagrammatic  series  showing  development  of  color-pattern  in  pupal  wings 
of  the  promethea  moth,  Callosamia  promethea;  female  wings  in  vertical  series  at  left, 
male  at  right.     (After  Mayer;    one-half  natural  size.) 

themselves,  however,  remain  white.  Fig.  784,  c,  shows  a  still  later  condition, 
where  the  dirty  yellow  ground-color  has  deepened  into  rufous,  and  the  black 
has  deepened  and  increased  in  area  and  has  also  begun  to  appear  along  the 
edges  of  the  nervures.  In  Fig.  784.  d,  the  black  has  finally  suffused  the 
nervures,  the  base  of  the  wing  and  the  submedian  nervure  being  the  only 


598 


Color  and  Pattern  and  their  Uses 


parts  that  still  remain  dull  yellow.  It  is  apparent  that  in  Anosia  plexippuSy 
as  in  CaUosamia  promethea,  the  central  areas  of  the  wings  are  the  first  to 
exhibit  the  mature  colors,  and  that  the  nervures  and  costal  edges  of  the 
wings  are  the  last  to  be  suffused." 

The  development  of  the  wing-patterns  in  the  male  and  the  female  of  the 
promethea  moth,  as  worked  out  by  Mayer,  is  shown  by  Fig.  785. 

Other  butterflies  and  moths  which  have  been  thus  followed  through 
the  pupal  life  show  a  similar  possession  of  color-appearance.  Tower  has 
similarly  followed  the  color-development  in  certain  beetles.  Tower's  figures 
illustrating  the  development  in  the  large    blackish-brown  Prionid  beetle, 


Fig.  786. — Diagrammatic  series  showing  development  of  color-pattern  in  pupae  and  young 
adults  of  the  giant  wood-boring  beetle,  Orthosoma  brunnea.  The  first  three  figures  in 
the  upper  line,  counting  from  the  left,  are  pupae  of  successive  ages,  the  rest  of  the 
figures  adults  of  successive  ages.     (After  Tower;    natural  size.) 


Orthosoma  hrimnea,  are  shown  in  Fig.  786.  Tower  finds  that  in  all  the 
insects  so  far  studied  the  chemical  colors  of  the  body  follow  the  general  course 
illustrated  by  Orthosoma.  The  color  begins  to  form  on  the  head  and  anterior 
parts  first  and  gradually  spreads  posteriorly. 


Color  and  Pattern  and  their  Uses  599 

Now  that  we  have  got  in  some  degree  acquainted  with  the  ways  in  which 
colors  are  actually  produced  among  insects,  we  may  come  back  to  the  ques- 
tion asked  in  the  first  paragraph  of  this  chapter,  namely,  "What  is  the  use 
to  the  insect  of  all  this  variety  of  color  and  pattern?"  We  may  attempt  now 
to  get  some  clue  to  the  significance  of  the  color  phenomenon.  So  wide-spread 
and  well  developed  are  color  and  pattern  among  insects  that  the  presump- 
tion is  strong  that  the  utility  of  color-pattern  is  large. 

The  only  hypothesis  that  gives  to  colors  and  markings  a  value  in  the  life 
of  insects  at  all  comparable  with  the  degree  of  specialization  reached  by 
these  colors  and  markings  and  by  the  special  structures  developed  to  make 
them  possible,  is  that  already  referred  to  as  the  theory  of  protective  and 
aggressive  resemblances,  of  warning  and  directive  patterns,  and  of  mimicry. 
These  various  uses  of  color-patterns  are  all  concerned  with  the  relation  of 
the  insect  to  its  environment;  they  are  means  of  protecting  the  insect  from 
its  enemies  or  of  enabling  it  to  capture  its  prey.  They  are  uses  obviously  con- 
cerned with  the  "struggle  for  existence";  they  are  "shifts  for  a  living." 
For  the  sake  of  clearness  in  the  discussion  of  these  various  uses — a  discussion 
which  must  by  the  limitations  of  space  be  most  unsatisfactorily  condensed — 
the  uses  will  be  rather  arbitrarily  classified  into  several  categories  which  in 
Nature  are  not  as  sharply  distinguished  as  the  paragraph  treatment  of  them 
might  suggest. 

General  protective  resemblance. — The  general  harmonizing  in  color  and 
pattern  with  the  color  scheme  of  the  usual  environment  is  a  condition  which 
every  field  student  of  insects  recognizes  as  widely  existing.  The  difficulty 
of  distinguishing  a  resting  moth  from  the  bark  on  which  it  is  resting,  a  green 
caterpillar  or  leaf-hopper  or  meadow  grasshopper  from  the  leaf  to  which  it 
clings,  a  roadside  locust  or  bug  from  the  soil  on  which  it  alights,  is  a  diffi- 
culty which  has  to  be  reckoned  with  by  every  collector.  Now  while  there 
are  few  human  collectors  of  insects,  there  are  hosts  of  bird  and  toad  and  lizard 
insect-hunters,  to  say  nothing  of  the  many  kinds  of  predaceous  insects  them- 
selves who  use  their  own  cousins  for  chief  food.  So  that  where  this  diffi- 
culty of  distinguishing  the  resting  insect  from  its  environment  is  sufficient 
to  postpone  success  on  the  part  of  the  insect-hunting  bird  or  lizard,  the  life 
of  the  protectively-colored  insect  is  obviously  saved,  for  the  time,  by  its  dress. 
This  is  a  utility  of  color  and  pattern  than  which  there  can  be,  from  the  insect 
point  of  view,  nothing  higher. 

Variable  protective  resemblance. — While  v/ith  most  insects  all  the  indi- 
viduals of  one  species  show  a  similar  color  and  pattern,  it  is  noticeable  that 
with  a  few  species  there  is  a  marked  variability  or  difference  in  color  and 
sometimes  in  markings.  Locusts  of  various  species  of  the  genus  Trimero- 
tropis  show  a  variability  in  color  of  individuals  ranging  through  gray,  brown, 
reddish,  plumbeous,  and  bluish,  and  such  accompanying  variablity  in  mark- 


6oo  Color  and  Pattern  and  their  Uses 

ing  as  to  result  in  producing  much  variety  of  appearance  in  a  single 
series  of  collected  individuals.  I  have  noted  in  collecting  these  locusts  in 
Colorado  and  California  that  this  variability  of  coloration  is  directly  associ- 
ated with  the  color-differences  in  the  soil  of  the  localities  in  which  these  locusts 
live;  the  reddish  individuals  are  taken  from  spots  where  the  soil  is  reddish, 
the  grayish  where  it  is  sand-colored,  and  the  plumbeous  and  bluish  from  soil 
formed  by  decomposing  bluish  rock. 

On  the  campus  of  Stanford  University  there  is  a  little  pond  whose  shores 
are  covered  in  some  places  with  bits  of  bluish  rock,  in  other  places  with  bits 
of  reddish  rock,  and  in  still  others  with  sand.  The  toad-bug,  Galgulus  ocula- 
tus,  lives  abundantly  on  the  banks  of  this  little  lake.  Specimens  collected 
from  the  blue  rocks  are  bluish  in  ground-color,  those  from  the  red  rocks 
are  reddish,  and  those  from  the  sand  are  sand-colored.  But  the  colors 
of  these  insects  are  fixed;  they  cannot,  like  the  chameleon  and  certain  other 
lizards,  or  like  numerous  small  fishes  and  some  tree-frogs,  change  color, 
quickly  or  slowly,  with  changes  in  position,  that  is,  movements  from  green 
to  brown  or  to  other  colored  environment.  Variable  protective  resemblance 
in  insects  is,  as  far  as  known,  a  variability  directly  induced,  to  be  sure,  by 
varying  environment,  but  all  acquired  during  the  development  of  the  in- 
dividual insects,  and  fixed  by  the  time  they  reach  the  adult  stage. 

The  well-known  experiments  of  Tr!men,  Miiller,  and  Poulton  with  the 
pupating  larvae  of  swallow-tailed  butterflies,  Papilio  sp.,  and  Poulton  on 
other  butterflies  with  naked  chrysalids,  show  that  the  chrysalids  of  numerous 
butterfly  kinds  take  on  the  color,  or  a  shade  approaching  it,  of  the  substance 
surrounding  the  pupating  larvse,  and  show  also  that  the  result  is  due  to  a 
stimulus  of  the  skin  by  the  enclosing  color,  and  not  to  a  stimulus  received 
through  the  eyes,  and  carried  to  the  skin  by  the  nerves.  Larvae  just  ready 
to  pupate  were  enclosed  in  boxes  lined  with  paper  of  different  colors;  the 
chrysalids  when  formed  were  found  to  be  colored  to  harmonize  with  that 
particular  color  of  paper  by  which  they  were  surrounded  while  pupating.  As 
these  chrysalids  in  Nature  hang  exposed  on  bark  and  in  other  unsheltered 
places,  without  protecting  cocoon  or  cover  of  any  kind,  the  actual  protective 
value  of  this  harmonious  coloration  is  obvious. 

The  larvae  (caterpillars)  of  various  moths,  particularly  Geometrid  and 
Sphingid  species,  often  appear  in  two  color  types,  one  brown  and  the  other 
green.  Poulton  has  shown  by  experiment  and  observation  with  some  of 
these  species  that  those  larvae  reared  among  green  leaves  and  twigs  and 
branches  become  brown.  This  variable  protective  resemblance,  like  that 
of  Trimerotropis,  Galgulus,  and  the  Papilio  chrysalids,  also  is  fixed  after 
being  once  acquired. 

An  interesting  example  of  color  harmony  whxh  may  be  class'fied  under 
the  head  of  variable  protective  resemblance  that  has  come  under  my  obser- 


Color  and  Pattern  and  their  Uses 


601 


vation  while  writing  this  chapter  is  the  case  of  the  larvas  of  Lycana  sp., 
abundant  on  the  flower-heads  of  the  just-blossoming  (May)  California 
buckeye,  .'Esculus  calijornicus.     The  buds  of  the  buckeye  are  green,  or  green 


Fig.    787. — The  dead-leaf  butterfly,  Kallima  sp.,  a  remarkable  case  of  special  protective 
resemblance.     (Natural  size.) 

and  rose,  or  even  all  rose  externally.     The  quiet  slug-like  Lycaenid  larvae 
lie  longitudinally  along  the  buds  and  their  short  stems,  and  are  either  green 


6o2  Color  and  Pattern  and  their  Uses 

with  faint  rosy  tinge,  especially  along  the  dorsi-meson,  or  are  distinctly 
rosy  all  over,  depending  strictly  upon  the  color-tone  of  the  particular  inflo- 
rescence serving  as  habitat  for  the  larva  (PI.  XIII,  Figs.  3,  4,  and  5).  The 
correspondence  in  shade  of  color  is  strikingly  exact:  the  utter  invisibility, 
or  rather  indistinguishability,  of  the  larvae  is  something  that  needs  to  be 
experienced  as  my  artist,  my  students,  and  I  have  experienced  it  in  the  last 
few  vv^eeks,  to  be  fairly  realized.  We  have  watched  the  larvae  through  their 
whole  life,  and  all  the  time  the  safe  position  along  the  bud  and  the  immobility 
are  maintained. 

Special  protective  resemblance. — The  figures  of  Kalhma  (PI.  XIII,  Fig.  i, 
also  text  Fig.  787)  and  of  Phyllium  (PI.  XIII,  Fig.  2,  also  text  Fig.  788), 
referred  to  in   an  early   paragraph  in  this  chapter,  illustrate  extreme  and 

often-referred-lo  examples  of  a  protective 
resemblance  which  may  be  called  "special" 
in  that  the  insect's  appearance  simulates  in 
more  or  less  nearly  exact  way  some  par- 
ticular part  of  the  habitual  environment,  this 
being,  in  the  case  of  Kallima,  a  dead  leaf, 
in  the  case  of  Phyllium  a  green  leaf.  The 
details  of  this  simulation  are  extreme:  in 
%^-'  >    Kallima  the  projections  or  tails  of  the  hind 

wings  represent  the  leaf -stem,  the  long  cen- 

^  /  /  tral  midrib  of   the  leaf   is  represented  by  a 

I  7  brown  line  continuously  across   both  wings, 

1  ''^  j  the   lateral   leaf-veins  corresponding   on  one 

\  '  side  to  the  actual  course  of  the  wing-veins, 

V  ^  ^'  but  on  the  other  being  represented  by  brown 

',  lines  running  at  right  angles,  nearly,  to  the 

\    /  wing-veins;    in  Phyllium   the    flattened  and 

^  expanded  head,  thorax,  legs,   and  abdomen 

Fig.  788. — The    green-leaf   insect,       -^i    .1      u        j  •  1      r       •      j 

Fhylluim^^.  This  insect  is  brigh;  With  the  broad  green  wmg-covers,  leaf -vemed 

green  with  scattered  yellowish  and  spotted  with  yellow  like  a  fungus- 
cltii^gMT'sC""  ''"''*<=d  or  insect-punctured  leaf  compose  a 
make  the  insect  almost  indistin-  false  picture  of  great  effectiveness.  Are 
guishable  when  at  rest  among  ^^^  ^j^ggg  ^g^ails  of  deceit  almost  past 
green  leaves.  ^ 

belief? 

The  slender  grass-green  larvae  of  many  moths  and  butterflies  are  much 
like  green  grass-leaves;  their  shmness  and,  if  Weismann's  interpretation 
be  accepted,  the  few  longitudinal  whitish  lines  which  serve  as  air-lines 
to  divide  the  body  into  two  or  three  (apparent)  grass-blades,  are  special 
characters  of  importance.  The  inch-worms  or  larvae  of  Geometrid  moths 
are    familiar    examples    of    special    protective    resemblance.     Abundant    as 


Color  and  Pattern  and  their  Uses 


60 


these  larvae  are,  they  are  only  occasionally  seen,  and  then  usually  when  "loop- 
ing" along  on  the  ground  or  sidewalk.  When  in  their  habitual  haunts  in 
trees  and  bushes,  the  slightest  disturbance,  as  the  approach  of  bird  or  lizard 
or  human  observer,  causes  them  to  "go  stiff,"  holding  the  body  (Fig.  789) 


Fig.  789. 


Fig.  790. 


Fig.  789. — An  inch-worm,  larva  of  geometrid  moth,  in  protective  position.     (After  Jor- 
dan and  Kellogg;    natural  size.) 
Fig.  790. — The  walking-stick,  or  twig-insect,  Diapheromera  jemorata.     (Slightly  enlarged.) 


rigidly  out  from  the  branch  or  stem  to  which  they  cling  by  the  posterior 
two  pairs  of  prop-legs,  and  looking  so  like  a  short  twig,  or  broken  one,  that 
they  are  only  rarely  recognized  for  what  they  really  are.     The  skin  is  brown  or 


6o4  Color  and  Pattern  and  their  Uses 

green  (variable  resemblance,  depending  on  their  nurture)  and  roughened 
and  tubercled  like  a  bud-scarred  bit  of  twig.  The  absence  of  the  middle 
prop-legs  prevents  the  harm  to  this  illusion  that  would  come  from  their  pres- 
ence. An  interesting  point  in  this  simulation — and  one  which  is  commoner 
in  such  cases  than  has  been  generally  referred  to — is  the  combining  of  a 
habit  or  kind  of  behavior  with  the  structural  and  color  modification  to  make 
the  illusion  successful. 

Another  familiar  and  extreme  case  of  special  protective  resemblance  is 
that  of  the  walking-stick,  or  twig-insect,  Diapheromera  jemoraia  (Fig.  790), 
a  Phasmid  wide-spread  over  the  whole  of  our  country.  The  absence  of 
vdngs,  the  extreme  elongation  and  slenderness  of  body  and  legs,  and  the 
dichromatic  condition,  individuals  being  either  green  or  brown,  all  com- 
bine to  make  this  insect  a  masterpiece  of  deceit.  The  moths  of  the  genus 
Cymatophora  and  their  larvae  also  mostly  harmonize  excellently  with  the 
gray  bark  on  which  they  rest;  the  moths  adding  to  their  general  simulation 
the  curious  habit  of  resting  often  with  folded  wings  at  an  angle  of  45°  with 
the  tree-trunk,  head  downwards,  with  the  curiously  blunt  and  uneven  wing- 
tips  projecting,  so  as  to  imitate  with  great  fideHty  a  short  broken-off  branch 
or  chip  of  bark.  Numerous  other  moths  and  caterpillars  resemble  bark 
and  habitually  rest  on  it.  The  Catocalas,  Schizura,  and  others  are  ex- 
amples famihar  to  the  moth-collector. 

Any  field  student  of  insects  by  paying  attention  to  the  matter  of  special 
protective  resemblance  can  soon  make  up  a  formidable  list  of  examples. 
Some  of  these  may  appeal  more  to  him  than  to  persons  seeing  his  speci- 
mens in  the  collecting-boxes,  and  some  indeed  will  probably  be  questionable 
to  other  naturalists.  But  nevertheless  no  collector  or  field  student  but  has 
noted  many  examples  of  this  clever  artifice  of  Nature  to  protect  her 
children. 

Warning  colors. — If  the  field  student  may  be  relied  on  to  note  and  record 
a  long  list  of  insects  colored  and  marked  so  as  to  harmonize  well  with  their 
general  environment  or  with  some  specific  part  of  it,  he  may  also  be  relied 
on  to  bring  in  a  list  of  opposites:  a  record  of  bizarre  and  conspicuous  forms, 
colored  with  brilliant  blues  and  greens  and  streaked  and  spotted  in  a  man-^ 
ner  utterly  at  variance  and  in  contrast  with  the  foliage  or  soil  or  bark  or 
whatever  is  the  usual  environment  of  the  insect.  The  great  red-brown  mon- 
arch butterfly  and  its  black-striped  green  and  yellowish  larva,  the  tiger- 
banded  swallowtails,  the  black  and  yellow  wasps  and  bees,  the  ladybird- 
beetles  with  their  sharply  contrasting  colors,  the  brilliant  green  blister-beetles, 
the  striped  and  spotted  Chrysomelids — in  all  these  and  many  others  there 
can  be  no  talk  of  protective  resemblance:  if  only  such  a  paradoxical  theory 
as  protective  conspicuousness  could  be  established,  then  these  colors  and 
markings  might  well  be  explained  by  it. 


Color  and  Pattern  and  their  Uses  605 

Exactly  such  an  explanation  of  brilliant  color  and  contrasting  markings 
is  afforded  by  the  theory  of  warning  colors.  It  has  been  conclusively  shown, 
by  observation  and  experiment,  by  several  naturalists,*  that  many  insects 
are  distasteful  to  birds,  lizards,  and  other  predaceous  enemies  of  the  insect 
class. 

The  blood-lymph  or  some  specially  secreted  body  fluid  of  these  insects 
contains  an  acrid  or  ill-tasting  substance  so  that  birds  will  not,  if  they  can 
recognize  the  kind  of  insect,  make  any  attempt  to  catch  or  eat  them.  This 
letting  alone  is  undoubtedly  the  result  of  previously  made  trials,  that  is,  has 
been  learned.  Now  it  would  obviously  be  of  advantage  to  those  species  of 
insects  that  are  ill-tasting  if  their  coloring  and  pattern  were  so  distinctive 
and  conspicuous  as  to  make  them  readily  learned  by  birds,  and  once  learned 


Fig.  791. — Larva  of  the  monarch  butterfly,  Anosia  plexippus,  conspicuously  marked  with 
black  and  whitish  yellow  rings,  and  distasteful  to  birds.     (Natural  size.) 

easily  seen.  A  distasteful  caterpillar  needs  to  advertise  its  unpalatability  so 
effectively  that  the  swooping  bird  will  recognize  it  before  making  that  single 
sharp  cutting  stroke  or  peck  that  would  be  about  as  fatal  to  a  caterpillar 
as  being  wholly  eaten.  Hence  the  need  and  the  utility  of  warning  colors. 
And  indeed  the  distasteful  insects  as  far  as  recognized  are  mostly  of  con- 
spicuous color  and  pattern. 

Such  warning  colors  are  presumably  possessed  not  only  by  unpalatable 
insects,  but  also  by  many  that  have  certain  special  means  of  defence.  The 
wasps  and  bees,  provided  with  stings,  dangerous  to  most  of  their  enemies, 
are  almost  all  conspicuously  marked  with  yellow  and  black.  Many  bugs, 
well  defended  by  sharp  beaks,  possess  conspicuous  color-patterns. 

Terrifying  appearances. — Certain  other  insects  which  are  without  special 
means  of  defence  and  are  not  at  all  formidable  or  dangerous  are  yet  so  marked 
or  shaped  and  so  behave  as  to  present  a  curiously  threatening  or  terrifying 
appearance.  The  large  green  caterpillars  of  the  sphinx-moths  have  a  curious 
rearing-up  habit  which  seems  to  simulate  threatened  attack  (Fig.  792). 
They  have,  too,  a  great  pointed  spine  or  horn  on  the  back  of  the  posterior 

*  A  most  interesting  recent  account  of  a  long  series  of  such  observations  and  experi- 
ments is  presented  in  "The  Bionomics  of  South  African  Insects,"  by  G.  K.  Marshall 
and  E.  B.  Poulton,  Trans.  Ent.  Soc.  Lond.,  1902.  This  paper  contains  the  records  of 
five  years  of  careful  study  in  the  field  of  the  phenomena  relating  to  the  theories  of  warning 
colors  and  mimicry. 


6o6 


Color  and  Pattern  and  their  Uses 


tip  of  the  body  which  has  a  most  formidable  appearance,  but  is,  as  a  matter 
of  fact,  not  at  all  a  weapon  of  defence,  being  quite  harmless.  Numerous 
stingless  insects  when  disturbed  wave  about  the  hind  part  of  the  body  or 
curl  it  over  or  under  much  as  stinging  insects  do,  and  seem  to  be  threatening 
to  sting.  The  striking  eye-spots  of  many  insects  are  believed  by  some 
entomologists  to  be  of  the  nature  of  terrifying  markings.  Marshall  tried 
feeding  baboons  a  full-grown  larva  (about   7  in.  long)  of  the  sphinx-moth, 


Fig.   792. — Larva  of  the  pen-marked  sphinx-moth,  Sphinx  chersis,  showing  threatening 
attitude.     (After  Comstock.) 


Chccrocampa  osiris.  The  larva  has  large  strongly  colored  eye-spots  and 
is  "remarkably  snake-like,  the  general  coloring  somewhat  recalling  that 
of  the  common  puff-adder,  Bitis  arietans.  The  female  baboon  ran  forward 
expecting  a  titbit,  but  when  she  saw  what  I  had  brought  she  flicked  it  out 
of  my  hand  on  to  the  ground,  at  the  same  time  jumping  back  suspiciously; 
she  then  approached  it  very  cautiously,  and  after  peering  carefully  at  it  from 
the  distance  of  about  a  foot  she  withdrew  in  alarm,  being  clearly  much 
impressed  by  the  large  blue  eye-like  markings.  The  male  baboon,  which 
has  a  much  more  nervous  temperament,  had  meanwhile  remained  at  a 
distance  surveying  the  proceedings,  so  I  picked  up  a  caterpillar  and  brought 


Color  and  Pattern  and  their  Uses  607 

it  towards  them,  but  they  would  not  let  me  approach,  and  kept  running 
away  round  and  round  their  pole,  so  I  threw  the  insect  at  them.  Their 
fright  was  ludicrous  to  see ;  with  loud  cries  they  jumped  aside  and  clambered 
up  the  pole  as  fast  as  they  could  go,  into  their  box,  where  they  sat  peering 
over  the  edge  watching  the  uncanny  object  below."  (Marshall.)  Marshall 
also  writes  concerning  the  eye-like  markings  on  the  wings  of  the  mantis, 
Pseudocreohotra  wahlbergi:  "They  are,  I  think,  almost  certainly  of  a  terrify- 
ing character.  When  the  insect  is  irritated  the  wings  are  raised  over  its 
back  in  such  a  manner  that  the  tegmina  stand  side  by  side,  and  the  markings 


Fig.  793. — Larva  of  the  puss-moth,  Centra  sp.;  upper  figure  showing  larva  in  normal 
attitude;  lower  figure  showing  larva  when  disturbed.  (After  Poulton;  enlarged.) 
(See  description  of  this  larva  on  p.  394.) 

on  them  then  present  a  very  striking  resemblance  to  the  great  yellow  eyes 
of  a  bird  of  prey  or  some  feline  animal,  which  might  well  deter  an  insec- 
tivorous enemy.  It  is  noticeable  that  the  insect  is  always  careful  to  keep 
the  wings  directed  towards  the  point  of  attack,  and  this  is  often  done  without 
altering  the  position  of  the  body." 

Directive  coloration. — Still  another  use  is  believed  by  some  entomologists 
to  be  afforded  by  such  markings  as  ocelli  and  other  specially  conspicuous 
spots  and  flecks  on  the  wings  of  butterflies  and  moths,  and  by  such  apparently 
useless  parts  as  the  "tails"  of  the  hind  wings  of  the  swallowtail  and  Lycaenid 
butterflies,  and  others.  Marshall  busied  himself  for  a  long  time  wiih  collect- 
ing butterflies  which  had  evidently  been  snapped  at  by  birds  (in  some  cases 
he  observed  the  actual  attack)  and  suffered  the  loss  of  a  part  of  a  wing. 
Examining  these  specimens  when  brought  together,  Poulton  and  Marshall 


6o8  Color  and  Pattern  and  their  Uses 

noted  that  the  "great  majority  [of  these  injuries  to  the  wings]  are  inflicted 
at  the  anal  angle  and  adjacent  hind  margin  of  the  hind  wing,  a  considerable 
number  at  or  near  the  apical  angle  of  the  fore  wing,  and  comparatively  few 
between  the  points."  In  this  fact,  coupled  with  the  fact  that  the  apical 
and  hind  angles  of  the  fore  and  hind  wings  respectively  are  precisely  those 
regions  of  the  wings  most  usually  specially  marked  and  prolonged  as  angular 
processes  or  tails,  Poulton  sees  a  special  significance  in  the  patterns  of  these 
wing-parts:  he  thinks  they  are  "directive  marks  which  tend  to  divert  the 
attention  of  an  enemy  from  more  vital  parts."  It  is  obvious  that  a  butterfly 
can  very  well  afford  to  lose  the  tip  or  tail  of  a  wing  if  that  loss  will  save  losing 
a  head  or  abdomen.  Poulton  sees  a  "remarkable  resemblance  of  the  marks 
and  structures  at  the  anal  angle  of  the  hind  wing,  under  side,  in  many 
Lycaenidae  to  a  head  with  antennae  and  eyes,"  and  recalls  that  this  has  been 
independently  noticed  by  many  other  observers.  "The  movements  of  the 
hind  wings  by  which  the  '  tails,'  the  apparent  antennae,  are  made  continually 
to  pass  and  repass  each  other  add  very  greatly  to  this  resemblance." 

Mimicry. — Of  all  the  theories  accounting  for  the  utility  of  color  and 
pattern,  that  of  mimicry  demands  at  first  thought  the  largest  degree  of  credulity. 
As  a  matter  of  fact,  however,  the  observation  and  evidence  on  which  it  rests 
are  as  convincing  as  are  those  for  almost  any  of  the  offered  explanations 
of  the  usefulness  of  color-pattern.  Although  the  word  mimicry  could  often 
have  been  used  aptly  in  the  account  of  special  protective  resemblance,  it 
has  been  reserved  for  use  in  connection  with  a  specific  kind  of  imitation, 
namely,  the  imitation  by  an  otherwise  defenceless  insect,  one  without  poison, 
beak,  or  sting,  and  without  acrid  and  distasteful  body  fluids,  of  some  other 
specially  defended  or  inedible  kind,  so  that  the  mimicker  is  mistaken  for 
the  mimicked  form  and,  like  this  defended  or  distasteful  form,  relieved  from 
attack.  Many  cases  of  this  mimicry  may  be  noted  by  any  field  student  of 
entomology . 

Buzzing  about  flowers  are  to  be  found  various  kinds  of  bees,  and  also 
various  other  kinds  of  insects,  thoroughly  bee-like  in  appearance,  but  in 
reality  not  bees  nor,  like  them,  defended  by  stings.  These  bee-mimickers 
are  mostly  flies  of  various  families  (Syrphidae,  Asilidae,  Bombyliidie),  and 
their  resemblance  to  bees  is  sufficient  to  and  does  constantly  deceive  collectors. 
We  presume,  then,  that  it  equally  deceives  birds  and  other  insect  enemies. 
Wasps,  too,  are  mimicked  by  other  insects;  the  wasp-like  flies,  Conopidas, 
and  some  of  the  clear-winged  moths,  Sesiidas  (Fig.  794),  are  extremely  wasp- 
like in  general  seeming. 

The  distasteful  monarch  butterfly,  Anosia  plexippus,  wide-spread  and 
abundant — a  "successful"  butterfly,  whose  success  undoubtedly  largely 
depends  on  its  inedibility  in  both  larval  and  imaginal  stage — is  mimicked 
with  extraordinary  fidelity  of  detail  by  the  viceroy,  Basilarchia  archippus 


Color  and  Pattern  and  their  Uses 


609 


(Plate  XI,  Figs,  i,  4,  also  text  Fig.  795).  The  Basilarchias,  constituting  a 
genus  of  numerous  species,  are  with  but  two  or  three  exceptions  not  at  all 
of  the  color  or  pattern  of  Anosia,  but  in  the  case  of  the  particular  species 
archippiis  not  only  the  red-brown  ground-color  but  the  fine  pattern  details 
in  black  and  whitish  copy  faithfully  the  details  in  Anosia;  only  in  the  addi- 


FlG.  794. — Various  moths  and  wasps,  the  moths  having  the  appearance  of  wasps,  prob- 
ably through  mimicry,  and  protected  by  being  mistaken  for  the  stinging  insects. 
(Photograph  by  author;    natural  size.) 


tion  of  a  thin  blackish  line  across  the  discal  area  of  the  hind  wings  does 
archippus  show  any  noticeable  difference.  Viceroy  is  believed  not  to  be  dis- 
tasteful to  birds,  but  its  close  mimicry  of  the  distasteful  monarch  undoubt- 
edly leads  to  its  being  constantly  mistaken  for  it  by  the  birds  and  thus  left 
unmolested. 

The  subject  of  mimicry  has  not  been  studied  largely  among  the  insects 
of  our  country,  but  in  the  tropics  and  subtropics  numerous  striking  examples 
of  mimetic  forms  have  been  noted  and  written  about.  The  members  of 
two  large  families  of  butterflies,  the  Danaida^  and  Heliconidae,  are  distasteful 
to  birds,  and  are  mimicked  by  many  species  of  other  butterfly  families,  espe- 
cially the  Pieridae,  and  by  the  swallowtails,  PapiUonidae.  Many  plates 
illustrating  such  cases  have  been  published  by  Poulton  and  Marshall,  Haase, 


6io 


Color  and  Pattern  and  their  Uses 


Weismann,  and  others.  Shelford,*  in  an  extended  account  of  mimicry  as 
exemplified  among  the  insects  of  Borneo,  refers  to  and  illustrates  many  striking 
examples  among  the  beetles,  the  Hemiptera,  Diptera,  Orthoptera,  Neurop- 
tera,  and  moths:  distasteful  Lycid  beetles  are  closely  mimicked  by  other 
beetles,  by  Hemiptera,  and  by  moths;  distasteful  ladybird -beetles  are  mim- 
icked by  Hemiptera,   Orthoptera,  and  by  other  beetles;    stinging  Hymen- 


FiG.  795._The  monarch  butterfly,  Anosia  plexippus  (above),   distasteful  to  birds,  and 
the  viceroy,  Basilarchia  archippiis  (below),  which  mimics  it. 

optera  are  mimicked  by  stingless  Hymenoptera,  by  beetles,  flies,  bugs,  and 
moths.  Poulton  and  Marshall,  in  their  account  of  mimicry  among  South 
African  insects,  publish  many  colored  plates  revealing  most  striking  resem- 
blances between  insects,  well  defended  by  inedibility  or  defensive  weapons, 
and  their  mimickers. 

Our  space  unfortunately  prevents  any  specific  consideration  of  these 
various  interesting  cases. 

The  special  conditions  under  which  mimicry  exists  have  been  studied  and 
are  of  extreme  interest.  It  is  obvious  that  the  inedible  or  defended  mimicked 
form  must  be  more  abundant  than  the  mimicker,  so  that  the  experi- 
menting young  bird  or  lizard  may  have  several  chances  to  one  of  getting  an 

*  Shelford,  R.       Observations  on  some  Mimetic  Insects  and  Spiders  from  Borneo 
and  Singapore,  Proc.  Zool.  Soc.  Lond.,  1902,  pp.  230  et  seq. 


Color  and  Pattern  and  their  Uses  6 1  i 

ill  taste  or  a  sting  when  he  attacks  an  insect  of  certain  type  or  pattern.  This 
requirement  of  relative  abundance  of  mimicker  and  mimicked  seems  actu- 
ally met,  as  proved  by  observation.  In  some  cases  only  females  of  a  species 
indulge  in  mimicry,  the  males  being  unmodified.  This  is  explained  on  the 
ground  of  the  particular  necessity  for  protection  of  the  egg-laden,  heavy- 
flying,  and  long-lived  and  hence  more  exposed  females,  as  compared  with 
the  lighter,  swifter,  shorter-lived  males. 

It  has  been  found  that  individuals  of  a  single  species  may  mimic  several 
different  species  of  defended  insects,  this  polymorphism  of  pattern  existing 
in  different  localities,  or  indeed  in  a  single  one.  Marshall  believes  that  the 
seasonal  polychromatism  of  certain  butterfly  species  is  associated  with  the 
mimicry  of  certain  defended  butterflies  of  different  species,  these  different 
species  appearing  at  different  times  of  the  year. 

Criticisms  and  general  consideration  of  the  foregoing  hypotheses  of 
color  use. — It  is  needless  to  say  that  such  hypotheses  and  theories  of  the 
utility  of  color  and  pattern  have  been  subjected  to  much  criticism,  both 
adverse  and  favorable.  The  necessity  for  limiting  results  within  the  working 
range  of  efficient  causes  has  been  the  soundest  basis,  to  my  mind,  for  the 
adverse  criticism  of  the  theories  of  special  protective  resemblance,  warning 
colors,  and  mimicry.  Until  recently  most  of  the  observations  on  which  the 
theories  are  based  have  been  simply  observations  proving  the  existence  of 
remarkable  similarities  in  appearance  or  equally  striking  contrasts  and 
bizarrerie.  The  usefulness  of  these  similarities  and  contrasts  had  been 
deduced  logically,  but  not  proved  experimentally  nor  by  direct  observation. 
In  recent  years,  however,  a  much  sounder  basis  for  these  theories  has  been 
laid  by  experimental  work.  There  is  now  on  record  a  large  amount  of  strong 
evidence  for  the  validity  of  the  hypothesis  of  mimicry.  Certainly  no  other 
hypothesis  of  equal  validity  with  those  of  protective  resemblance  and  mimi- 
cry has  been  proposed  to  explain  the  numerous  striking  cases  of  similarity 
and  the  significant  conditions  of  life  accompanying  the  existence  of  these 
cases,  which  have  been  recorded  as  the  result  of  much  laborious  and  indefati- 
gable study  by  certain  naturalists. 

Plateau  and  Wheeler  have  tasted  so-called  inedible  or  distasteful  insects 
and  found  nothing  particularly  disagreeable  about  them.  But  as  Poulton 
suggests,  the  question  is  not  as  to  the  palate  of  Plateau  and  Wheeler  nor  of 
any  men:  it  concerns  the  tastes  of  birds,  lizards,  etc.  Better  evidence  is 
that  afforded  by  actual  observation  of  feeding  birds  and  lizards;  of  experi- 
mental offering  under  natural  conditions  of  alleged  distasteful  insects  to 
their  natural  enemies.  Marshall's  observations  and  experiments  on  the 
point  are  suggestive  and  undoubtedly  reliable.  Much  more  work  of  the 
same  kind  is  needed. 

The  efficient  cause  for  bringing  color  and  pattern  up  to  such  a  high 


6l2 


Color  and  Pattern  and  their  Uses 


degree  of  specialization  has  been  assumed,  by  nearly  all  upholders  of  the 
use  hypotheses,  to  be  natural  selection.  This  agent  can  account  for  pur- 
posefulness,  which  is  obviously  an  inherent  part  of  all  the  hypotheses.  And 
no  other  suggested  agent  can.  Weismann  makes,  indeed,  of  this  fact,  by 
inverting  the  problem,  one  of  his  most  effective  arguments  for  the  potency 
and  Allmacht  of  natural  selection.  He  declares  that  the  existence  of 
special  protective  resemblance,  warning  colors,  and  mimicry  proves  the 
reality  of  selection.  But  it  must  be  asked,  while  admitting  the  cogency  of 
much  of  the  argument  for  natural  selection  as  the  efficient  cause  of  high 
speciaUzation  of  color  and  pattern  as  we  have  seen  it  actually  to  exist,  how 
such  a  condition  as  that  shown  by  the  mimicking  viceroy  butterfly  has  come 
to  be  gradually  developed,  gradual  development  being  confessedly  selection's 


Fig.  796. — The  owl-butterfly,  Caligo  sp.,  under  side.     (Two-thirds  natural  size;    photo- 
graph by  the  author.) 

only  mode  of  working.  Could  the  viceroy  have  had  any  protection  for  itself, 
any  advantage  at  all,  until  it  actually  so  nearly  resembled  the  inedible  mon- 
arch as  to  be  mistaken  for  it?  No  slight  tinge  of  brown  on  the  black  and 
white  wings  (typical  color  scheme  of  the  genus),  no  slight  change  of  mark- 
ing would  be  of  any  service  in  making  the  viceroy  a  mimic  of  the  monarch. 
The  whole  leap  from  typical  Basilarchia  to  (apparently)  typical  Anosia  had 
to  be  made  practically  at  once.     On  the  other  hand  is  it  necessary  for  Kallima, 


Color  and  Pattern  and  their  Uses 


613 


the  simulator  of  dead  leaves,  to  go  so  far  as  it  has  in  its  modification?  Such 
minute  points  of  detail  are  there  as  will  never  be  noted  by  bird  or  Hzard. 
The  simple  necessity  is  the  effect  of  a  dead  leaf;  that  is  all.  Kallima 
certainly  does  that  and  more.  Kallima  goes  too  far,  and  proves  too  much. 
And  there  are  other  cases  like  it.  Natural  selection  alone  could  never  carry 
the  simulation  past  the  point  of  full  advantage. 

But  v^^hatever  other  factors  or  agents  have  played  a  part  in  bringing 
about  this  specialization  of  color  and  pattern,  exemplified  by  insects  showing 
protective  resemblances,  warning  colors,  terrifying  manners,  and  mimicry, 
natural  selection  has  undoubtedly  been  the  chief  factor,  and  the  basis  of 


Fig.  797. — The  death's-head  sphinx-moth.     (Photograph  by  the  author.) 

Utility  the  chief  foundation,  for  the  development  of  the  specialized  condi- 
tions. 

If  any  readers  of  this  brief  discussion  of  color  and  its  uses  among  the 
insects  care  to  refer  to  more  detailed  accounts  of  the  general  subject  of  color 
and  pattern,  or  to  parts  of  it,  they  will  find  the  following  books  and  papers 
useful:  Poulton's  "  The  Colour  of  Animals" ;  Beddard's"  Animal  Coloration"; 
Newbigin's  "Color  in  Nature";  Wallace's  "Darwinism,"  Chaps.  VIII,  IX, 
and  X;  papers  by  Mayer  on  "The  Development  of  the  Wing-scales  and  their 
Pigment  in  Butterflies  and  Moths"  (Bull.  Mus.  Comp.  ZooL,  Vol.  XXIX, 
No.  5,  1896),  on  "The  Color  and  Color-patterns  of  Moths  and  Butterflies" 
(Bull.  Mus.  Comp.  ZooL,  Vol.  XXX,  No.  4,  1897),  and  on  "Effects  of  Natural 
Selection  and  Race-tendency  upon  the  Color-patterns  of  Lepidoptera  "  (Bull. 


6 14  Color  and  Pattern  and  their  Uses 

Brooklyn  Inst.  Arts  and  Sci.,  Vol.  I,  No.  2,  1902);  a  paper  by  Tower  on 
"Color  and  Color-patterns  of  Coleoptera"  (Decenn.  Pubs.  Univ.  of  Chicago, 
Vol.  X,  1903);  a  paper  by  Kellogg  on  "The  Taxonomic  Value  of  the  Scales 
of  the  Lepidoptera  "  (Kansas  Univ.  Quar.,  Vol.  Ill,  No.  i,  1894);  the  papers 
by  Poulton  and  Marshall  referred  to  on  page  605,  and  that  by  Shelf ord 
referred  to  on  page  610. 


CHAPTER   XVIII 
INSECTS  AND  DISEASE 

IHROUGHOUT  this  book  reference  is  constantly 
made  to  the  injuries  done  by  insects  to  our 
forest-trees,  flowers,  fruits,  vegetables,  and 
grains.  The  millions  of  dollars  lost  annually 
because  of  the  sap-sucking  of  the  San  Jose 
scale,  the  grape-phylloxera,  the  chinch-bug, 
and  the  Hessian  fly,  and  the  biting  and  chewing 
of  beetles  and  caterpillars,  grubs  and  borers, 
are  a  sort  of  direct  tax  paid  by  farmers  and 
fruit-growers  for  the  privilege  of  farming  and  growing  fruit.  If  this  tax 
were  levied  by  government  and  collected  by  agents  with  two  feet  instead 
of  being  levied  by  Nature  and  collected  by  six-footed  agents,  what  a  swift 
revolt  there  would  be!  But  we  have,  most  of  us,  a  curious  inertia  that  leads 
us  to  suffer  with  some  protesting  complaint  but  little  protesting  action  the 
"ways  of  Providence,"  even  when  we  fairly  well  recognize  that  Providence 
is  chiefly  ourselves. 

When  we  reflect  on  the  four  hundred  millions  of  dollars  a  year  lost  to 
our  pockets  by  insect  ravages  we  may  incline  to  believe  that  the  only  kind 
of  insect  study  which  should  claim  our  attention  is  the  study  of  how  to  rid 
our  lands  of  these  pests.  We  may  be  excused  for  affirming  of  bugs,  as  was 
said  of  Indians  by  some  epigrammatist,  that  the  only  good  ones  are  the 
dead  ones.  When,  however,  we  learn,  as  we  are  learning  in  these  present 
days,  that  insects  are  not  simply  serious  enemies  of  our  crops  and  purses, 
but  are  truly  dangerous  to  our  very  health  and  life,  we  must  become  still 
more  extravagant  in  our  condemnatory  expressions  concerning  them. 

W^e  have  long  looked  on  mosquitoes,  house-flies,  and  fleas  as  annoyances 
and  even  torments,  but  that  each  of  these  pests  actually  acts  as  an  inter- 
mediate host  for,  and  is  an  active  disseminator  of,  one  or  more  wide-spread 
and  fatal  diseases  is  knowledge  that  has  been  got  only  recently.  Mosquitoes 
help  to  propagate,  and  are,  almost  certainly,  the  exclusive  disseminating  agents 

615 


6i6  Insects  and  Disease 

of  malaria,  yellow  fever,  and  the  various  forms  of  filariasis;  house-flies  aid 
in  spreading  typhoid  fever  and  other  diseases;  fleas  are  agents  in  distribut- 
ing the  germs  of  bubonic  plague.  Other  insects  are  known  to  spread  other 
diseases.  Howard  says:  "While  in  malaria  and  typhoid  we  have  two 
principal  diseases  common  to  the  United  States  which  may  be  conveyed 
by  insects,  the  agency  of  these  little  creatures  in  the  transfer  of  the  disease-germs 
is  by  no  means  confined  to  human  beings.  In  Egypt  and  in  the  Fiji  Islands 
there  is  a  destructive  eye-disease  of  human  beings  the  germs  of  which  are 
carried  by  the  common  house-fly.  In  our  southern  states  an  eye-disease 
known  as  pinkeye  is  carried  by  certain  very  minute  flies  of  the  genus  Hip- 
pelates.  The  so-called  Texas  fever  of  cattle  is  unquestionably  transferred 
by  the  common  cattle-tick,  and  this  was  the  earliest  of  the  clearly  demonstrated 
cases  of  the  transfer  of  disease  by  insects.  In  Africa  a  similar  disease  of 
cattle  is  transferred  by  the  bite  of  the  famous  biting  fly  known  as  the  tsetse- 
fly.  The  germs  of  the  disease  of  cattle  known  as  anthrax  are  carried  by 
gadflies,  or  horse-flies,  and  when  these  flies  subsequently  bite  human  beings 
malignant  pustules  may  result.  And  other  discoveries  of  this  nature  are 
constantly  being  made.  Even  the  common  bedbug  is  strongly  suspected 
in  this  connection." 

These  statements  are  not  guesses;  they  are  proved  facts  of  science.  It 
will  be  some  time  before  these  facts  and  their  significance  receive  their  full 
recognition  in  medical  practice;  the  knowledge  of  medicine  is  always  in 
advance  of  its  practical  recognition.  But  modern  medical  practice  is  much 
swifter  to  incorporate  the  new  facts  of  biology  than  was  the  practice  of  even 
a  decade  or  two  ago,  and  in  such  lines  of  work  as  army  and  other  govern- 
mental service  the  new  methods  of  preventive  medicine  are  quickly  adopted. 
Already  there  are  organized  movements  all  over  the  world  to  make  use  of 
the  new  knowledge  concerning  the  relation  of  insects  to  human  disease. 
As  I  write  these  pages  comes  the  report  of  the  work  of  Major  Ronald  Ross, 
one  of  the  discoverers  of  the  malaria-disseminating  capacity  of  the  mosquito 
and  one  of  the  leaders  in  the  anti-mosquito  crusade,  in  nearly  stamping  out 
malaria  in  the  long  notorious  pest-hole  of  Ismailia.  Malarial  cases  have  been 
reduced  there  from  300,000  cases  annually  to  300,  by  effective  war  on  mos- 
quitoes. Dr.  Cruz  reports  that  Rio  Janeiro  has  abolished  its  old-fashioned 
quarantine  regulations,  and  vessels  with  yellow  fever  on  board  will  hereafter 
simply  be  disinfected  and  supervised.  In  October,  1903,  Cruz  directed  the 
operations  of  twelve  hundred  men  specially  employed  in  destroying  the 
larvae  of  the  mosquito  in  their  breeding-places  in  and  around  the  city,  and  as 
a  result  only  nine  cases  of  yellow  fever  developed  in  the  midsummer  months 
of  January  and  February  (1904),  as  against  275  cases  in  the  same  months 
in  1903.  In  the  period  from  1850  to  1896,  51,600  deaths  occurred  in  Rio 
Janeiro  from  this  disease,  and  at  times  as  many  as  2000  patients  have  been 


Insects  and  Disease  617 

cared  for  in  the  isolation  hospital,  which  is  now  closed.  The  benefits  of  the 
war  waged  on  the  mosquito  at  Rio  Janeiro  have  been  as  great  as  those  obtained 
at  Havana,  where  the  vigorous  work  of  the  American  authorities  during  our 
occupation  of  the  islands  practically  stamped  out  yellow  fever  in  a  city  long 
notorious  the  world  over  as  a  plague-center. 

Mosquitoes  and  malaria. — First  of  these  known  cases  of  the  dissemina- 
tion of  human  disease  by  insects  to  be  worked  out  in  detail  was  the  relation 
of  mosquitoes  to  the  breeding  and  distribution  of  the  causative  germs  of 
malaria.  Malarial  fevers  occur  the  world  over  and  have  long  been  associated 
in  the  popular  mind  with  low  wet  localities  or  with  localities  near  marsh 
or  swamp.  Mosquitoes  live  in  great  abundance  precisely  in  such  regions, 
but  for  a  long  time  no  association  between  mosquitoes  and  malaria  was 
even  suspected.  Miasma,  the  effluvia  from  low  wet  ground,  was  held  to  be 
the  causative,  or  at  least  carrying,  agent  of  malaria.  It  was  not  until  1880, 
when  Laveran  discovered  and  described  the  actual  parasitic  sporozoon 
(minute  one-celled  amoeba-like  animal)  of  malaria,  that  the  actual  cause  of  the 
disease  was  recognized. 

Malaria  as  we  know  it  in  the  United  States  is  a  wide-spread  and  serious 
disease,  but  not  commonly  a  fatal  one.  But  in  India  five  million  deaths 
occurred  in  a  single  year,  1897,  from  malarial  fever.  Giles  declares  that  the 
malarial  parasite  is  responsible  for  by  far  the  greatest  proportion  of  all  sick- 
ness and  death  in  the  tropics.  "Cholera  and  plague,"  he  says,  "are  the 
indgnificant  enemies  that  perhaps  kill  a  few  thousands  a  year — in  an  impres- 
sive way,  it  is  true;  but  the  quiet  insidious  malaria  sweeps  off  its  millions." 
The  serious  state  of  affairs  in  India,  as  well  as  on  the  Gold  Coast  of  Africa, 
on  the  Roman  Campagna,  and  in  other  notoriously  malaria-stricken  regions, 
finally  led  to  careful  scientific  study  of  the  life -history  of  the  malaria-pro- 
ducing sporozoon  by  well-trained  English  and  Italian  physicians  and  natu- 
ralists, with  the  result  that  we  now  know  in  definite  and  accurate  detail  the 
whole  marvelous  story  of  the  interrelations  of  the  malarial  parasite,  the 
mosquito,  and  the  human  host.  ,^''^^, 

Lankester  was  the  first  to  find  an  amoeba-like  parasite  living  in  the  blood 
of  animals,  Drepanidium  ranarum  of  frog's  blood,  but  since  his  discovery 
numerous  other  similar  protozoon  blood-parasites,  collectively  called  Haema- 
tozoa,  have  been  found  in  reptiles,  birds,  bats,  cattle,  and  monkeys.  The 
haematozoon  infesting  cattle  discovered  by  Theobald  Smith,  an  American 
investigator,  produces  the  disease  known  as  Texas  fever,  and  is  spread  from 
animal  to  animal  by  ticks.  The  particular  blood-parasites,  called  Haema- 
mcebae,  which  produce  malarial  fevers,  are  not  restricted  to  man  alone,  but 
infest  birds,  bats,  and  monkeys  as  well. 

In  1885  Golgi  discovered  that  the  malaria-producing  Hasmamoebae  of  the 
human  body  exist  in  three  varieties,  each  apparently  responsible  for  one 


6i8 


Insects  and  Disease 


of  the  three  well-known  types  of  malarial  fever,  namely,  quartan,  tertian^ 
and  remittent.  And  soon  after  1885,  Golgi  and  other  investigators,  Itahan, 
English,  and  American  (Celli,  Grassi,  Mannaberg,  Bignami,  Danielewsky^ 
Carter,  Osier,  Labbe,  Koch,  Manson,  Councilman,  Thayer,  MacCallum, 
and  others),  succeeded  in  working  out  in  minute  detail  the  behavior,  develop- 
ment, and  pathological  effects,  direct  and  indirect,  of  the  parasites  in  the 
human  blood.  From  these  researches  I  may  summarize  the  life  of  the  malaria- 
producing  Haemamoebae  in  the  human  body  as  follows:  The  youngest  para- 
sites, or  amoebulae,  are  found  living  within  the  red  blood-corpuscles;  here 
they  grow  at  the  expense  of  the  corpuscle  substance.  They  increase  rapidly 
in  size,  while  the  blood-corpuscle  begins  to  degenerate.  From  the  break- 
ing down  of  the  haemoglobin  of  the  corpuscle,  due  to  the  metabolism  of  the 


Fig.  798. — Diagrammatic  figure  of  stages  in  the  development  of  the  malaria-producing 
Hsemamoeba  (Plasmodium)  in  a  red  blood-corpuscle  of  the  human  body. 


parasite,  granules  of  a  blackish  pigment  are  formed;  this  is  the  melanin 
long  known  as  a  regular  diagnostic  characteristic  of  malaria.  After  a  few 
days,  from  one  to  several  depending  on  the  variety  oi  the  Haemamoeba,  the 
amoebulag  reach  maturity.  They  begin  now  to  sporulate;  that  is,  the  nucleus 
and  cytoplasm  divide  into  many  small  parts,  each  nuclear  part  having  aggre- 
gated about  it  part  of  the  cytoplasm.  The  walls  of  the  blood-corpuscle  then 
break,  and  these  many  Haemamoeba  spores  are  released  into  the  blood -plasma. 
Each  of  these  spores  soon  attaches  itself  to  a  fresh  blood-corpuscle,  pene- 
trates it,  and  begins  a  new  life-cycle.     It  is  obvious  that  such  a  parasitic  life 


Insects  and  Disease  6 1 9 

in  the  blood-corpuscles,  using  up  their  substance  and  breaking  them  down, 
must  work  much  harm  to  the  human  body.  This  harm  is  exactly  that  which 
we  recognize  as  the  result  of  malaria.  The  fever  and  other  ills  that  are  a 
part  of  malaria  are  the  direct  and  indirect  pathological  effects  of  the  growth 
and  metabohsm  and  multiplication  of  the  Haemamoebs  in  our  blood.  From 
a  single  infection  the  sporulation  or  escape  of  the  myriads  of  spores  from  the 
breaking-down  corpuscles  into  the  blood-plasma  takes  place  practically  simul- 
taneously and  makes  the  beginning  of  the  malarial  spasm.  This  kind  of 
multiplication  of  the  Ha^mamoebae,  by  sporulation,  is  termed  asexual;  there 
is  no  participation  of  individuals  of  two  kinds,  or  sexes,  in  the  reproduction. 
It  is  a  sort  of  multiplication  common  to  a  great  many  minute,  simple  animals 
and  plants,  but  it  does  not  seem  in  any  of  these  to  be  the  only  mode  of  mul- 
tiplication. Scores,  even  hundreds,  of  successive  generations  may  be  pro- 
duced asexually,  but  finally  there  occurs  another  kind  of  reproduction,  which 
has  for  its  essential  characteristic  the  meeting  and  fusing  of  the  nuclei  or 
parts  of  them,  and  sometimes  the  body  protoplasm  or  parts  of  it,  of  two 
individuals  of  the  species.  In  all  but  the  very  simplest  organisms  these  two 
conjugating  individuals  differ  somewhat  in  size,  shape,  and  manner  of  behavior. 
Scientists  began  to  ask  when  and  how  and  where  conjugation  occurred  in 
the  Haemamoebae  of  malaria;  their  questioning  was  made  more  insistent  by 
the  discovery  that  some  of  the  amoebulae  in  the  blood -corpuscles  did  not  sporu- 
late,  but  continued  to  circulate  in  the  blood  without  any  particular  function 
at  all.  More  than  that,  it  was  noted  that  whenever  they  were  withdrawn 
from  the  circulation,  as  when  a  drop  of  blood  was  taken  out  of  the  skin  with 
a  pipette  for  examination  under  the  microscope,  these  traveling  amoebulae 
would  swell  up  and  liberate  themselves  from  their  enclosing  corpuscle,  and 
that  some  of  them  would  emit  a  number  of  long  motile  filaments;  these  fila- 
ments could  be  seen  lashing  about  strongly,  and  often  succeeded  in  breaking 
away  from  the  parent  cell,  and  darting  away  among  the  corpuscles.  This 
phenomenon  can  always  be  observed  in  the  blood  drawn  from  a  malarial 
patient,  in  from  ten  to  fifteen  minutes  after  its  withdrawal  from  the  circula- 
tion. What  is  the  meaning  of  it  ?  A  further  insistent  question  came  up  at 
this  time.  And  that  is.  If  the  Haemamoebae  are  the  actual  and  sole  cause  of 
malaria,  how  do  they  get  from  man  to  man?  How  is  the  malaria  dissem- 
inated ? 

The  explanation  of  the  significance  of  the  phenomenon  of  the  formation 
of  the  motile  filaments  from  amoebulae  in  blood  withdrawn  from  circulation, 
and  the  answer  to  the  question  as  to  the  mode  of  transmissibility  of  malaria, 
are  closely  connected,  and  were  reached  chiefly  through  the  brilliant  work 
of  Manson  and  Ross,  two  English  investigators  of  tropical  diseases.  Espe- 
cially interesting  is  the  work  of  Ross  in  establishing  the  actual  fact  of  the  carry- 
ing by  the  mosquito  of  the  Haemamoebae  from  man  to  man.      The  following 


620  Insects  and  Disease 

long  quotation  from  Ross,  taken  from  a  lecture  delivered  by  him  on  March  2, 
1900,  before  the  Royal  Institution  of  Great  Britain,  gives  a  detailed  account 
of  this  work,  answers  both  the  questions  asked  above,  and  at  the  same  time 
serves  to  reveal  a  typical  instance  of  the  faith  and  persistence  of  the  men 
to  whom  we  owe  scientific  progress. 

"It  was  reserved  for  Manson,"  says  Ross,  "to  detect  the  ultimate  (though 
not  the  immediate)  functions  of  these  bodies  [the  motile  filaments].  He 
asked  why  the  escape  of  the  motile  filaments  occurs  only  after  the  blood 
is  abstracted  from  the  host  (a  fact  agreed  upon  by  many  observers).  From 
his  study  of  these  filaments,  of  their  form  and  their  characteristic  movements, 
he  rejected  the  Italian  view  that  they  are  regressive  forms;  he  was  convinced 
that  they  are  living  elements.  Hence  he  felt  that  the  fact  of  their  appearance 
•only  after  abstraction  from  the  blood  (about  fifteen  minutes  afterwards) 
must  have  some  definite  purpose  in  the  life-scheme  of  the  parasites.  What 
is  that  purpose  ?  It  is  evident  that  these  parasites,  like  all  others,  must  pass 
from  host  to  host;  all  known  parasites  are  capable  of  not  only  entering  the 
host,  but,  either  in  themselves  or  their  progeny,  of  leaving  him.  Manson 
himself  had  already  pushed  such  methods  of  inductive  reasoning  to  a  bril- 
liantly successful  issue  in  discovering  by  their  means  the  development  of 
Filaria  nocturna  in  the  gnat.  He  now  applied  the  same  methods  to  the 
study  of  the  parasites  of  malaria.  Why  should  the  motile  filaments  appear 
only  after  abstraction  of  the  blood?  There  could  be  only  one  explanation. 
The  phenomenon,  though  it  is  usually  observed  in  a  preparation  for  the 
microscope,  is  really  meant  to  occur  ivithin  the  stomach-cavity  oj  some  suctorial 
insect,  and  constitutes  the  first  step  in  the  life-history  of  the  parasite  outside 
the  vertebrate  host. 

"It  is  perhaps  impossible  for  any  one,  except  one  who  has  spent  years  in 
revolving  the  subject,  to  understand  the  full  value  and  force  of  this  remarkable 
induction.  To  my  mind  the  reasoning  is  complete  and  exigent.  It  was 
from  the  first  impossible  to  consider  the  subject  in  the  light  which  Manson 
placed  it  without  feeling  convinced  that  the  parasite  requires  a  suctorial 
insect  for  its  further  development.  And  subsequent  events  have  proved 
Manson  to  have  been  right. 

"The  most  evident  reasoning — the  connection  between  malarial  fever 
and  low-lying  water-logged  areas  in  warm  countries — suggested  at  once 
that  the  suctorial  insect  must  be  the  gnat  (called  mosquito  in  the  tropics); 
and  this  view  was  fortified  by  numerous  analogies  which  must  occur  at  once 
to  any  one  who  considers  the  subject  at  all,  and  which  it  is  not  necessary  to 
discuss  in  this  place. 

"Needless  to  say,  since  Manson's  theory  was  proved  to  be  the  right 
one  it  has  been  shown  to  be  not  entirely  original.  Nuttall,  in  his  admirable 
history  of  the  mosquito  theory,  demonstrates  its  antiquity.     Eleven  years 


Insects  and  Disease  621 

before  Manson  wrote,  King  had  already  accumulated  much  evidence,  based 
on  epidemiological  data,  in  favor  of  the  theory.  A  year  later  (1884),  Laveran 
himself  briefly  enunciated  the  same  views,  on  the  analogy  with  Filaria  noc- 
turna.  Koch  and,  later,  Bignami  and  Mendini  were  also  advocates  of 
the  theory — partly  on  epidemiological  grounds  and  partly  because  of  a  possible 
analogy  with  the  protozoal  parasites  of  Texas  cattle-fever  which  Smith  and 
Kilborne  had  shown  to  be  carried  by  a  tick.  Hence  many  observers  had' 
independently  arrived  at  the  same  theory  by  different  routes.  .  .  . 

"To  leave  these  interesting  theories  and  to  return  to  actual  observations — 
I  should  begin  by  remarking  that  Manson  thought  the  motile  filaments  to 
be  of  the  nature  of  zoospores — that  is,  motile  spores  which  escape  from  the 
gametocytes  in  the  stomach-cavity  of  the  gnat,  and  then  occupy  and  infest 
the  tissues  of  the  insect.  In  this  he  was  proved,  two  years  later,  to  have 
been  wrong.  The  motile  filaments  are  not  spores,  but  microgametes — that 
is,  bodies  of  the  nature  of  spermatozoa.  I  have  said  that  some  of  the  amoebula? 
in  the  blood-corpuscles  of  the  host  become  sporocytes,  which  produce  asexual 
spores  (nomospores) ;  while  other  amcebulas  become  gametocytes,  which 
have  no  function  within  the  vertebrate  host.  As  soon,  however,  as  these 
gametocytes  are  ingested  by  a  suctorial  insect  they  commence  their  proper 
functions.  As  their  name  indicates,  they  are  sexual  cells — male  and  female. 
About  fifteen  minutes  after  ingestion  (in  some  species)  the  male  gametocytes 
emit  a  variable  number  of  microgametes — the  motile  filaments — which 
presently  escape  and  wander  in  search  of  the  female  gametocytes.  These 
contain  a  single  macrogamete,  or  ovum,  which  is  now  fertilized  by  one  of  the 
microgametes,  and  becomes  a  zygote.  We  owe  this  beautiful  discovery 
to  the  direct  observation  of  MacCallum  (1897),  confirmed  by  Koch  and 
Marchoux,  and  indirectly  by  Bignami.  .  .  .  Directly  MacCallum's  discovery 
was  announced  Manson  saw  the  important  bearing  of  it  on  the  mosquito. 
Admitting  that  the  motile  filaments  themselves  do  not  infect  the  gnat,  he 
at  once  observed  that  it  was  probably  the  function  of  the  zygote  to  do  so — 
and  this  time  he  was  perfectly  right. 

"I  must  now  turn  to  my  own  researches.  Dr.  Manson  told  me  of  his 
theory  at  the  end  of  1894,  and  I  then  undertook  to  investigate  the  subject 
as  far  as  possible.  I  began  work  in  Secunderabad,  India,  in  April,  1895; 
and  should  take  the  present  opportunity  for  acknowledging  the  continu- 
ous assistance  and  advice  which  I  received  from  Dr.  Manson  and  from 
Dr.  Laveran,  and  later  from  the  Government  of  India.  Even  with  the  aid  of 
the  induction  the  task  so  lightly  commenced  was,  as  a  matter  of  fact,  one 
of  so  arduous  a  nature  that  we  must  attribute  its  accomplishment  largely 
to  good  fortune.  The  method  adopted — the  only  method  which  could  be 
adopted — was  to  feed  gnats  of  various  species  on  persons  whose  blood  con- 
tained the  gametocytes,  and  then  to  examine  the  insects  carefully  for  the 


622  Insects  and  Disease 

parasites  which  by  hypothesis  the  gametocytes  were  expected  to  develop 
into.  This  required  not  only  familiarity  with  the  histology  of  gnats,  but  a 
laborious  search  for  a  minute  organism  throughout  the  whole  tissues  of  each 
individual  insect  examined — a  work  of  at  least  two  or  three  hours  for  each 
gnat.  But  the  actual  labor  involved  was  the  smallest  part  of  the  difficulty. 
Both  the  form  and  appearance  of  the  object  which  I  was  in  search  of,  and 
the  species  of  the  gnat  in  which  I  might  expect  to  find  it,  were  absolutely 
unknown  quantities.  We  could  make  no  attempt  to  predict  the  appearance 
which  the  parasite  would  assume  in  the  gnat;  while  owing  to  the  general 
distribution  of  malarial  fever  in  India,  the  species  of  insect  concerned  in  the 
propagation  of  the  disease  could  scarcely  be  determined  by  a  comparison 
of  the  prevalence  of  different  kinds  of  gnat  at  different  spots  with  the  preva- 
lence of  fever  at  those  spots.  In  short,  I  was  forced  to  rely  simply  on  the 
careful  examinations  of  hundreds  of  gnats,  first  of  one  species  and  then  of 
another,  all  fed  on  patients  suffering  from  malarial  fever — in  the  hope  of 
one  day  finding  the  clue  I  was  in  search  of.  Needless  to  say,  nothing  but 
the  most  convincing  theory,  such  as  Manson's  theory  was,  would  have  sup- 
ported or  justified  so  difficult  an  enterprise. 

"  As  a  matter  of  fact,  for  nearly  two  and  a  half  years  my  researches  were 
almost  entirely  negative.  I  could  not  obtain  the  correct  scientific  names  of 
the  various  species  of  gnats  employed  by  me  in  these  researches,  and  con- 
sequently used  names  of  my  own.  Gnats  of  the  genus  Culex  (which  abound 
almost  everywhere  in  India)  I  called  'gray'  and  'brindled'  mosquitoes; 
and  it  was  these  insects  which  I  studied  during  the  period  referred  to*  At 
last,  the  particular  nugatory  results  which  had  been  obtained  with  gnats 
of  this  genus  determined  me  to  try  other  methods.  I  went  to  a  very  mala- 
rious locality,  called  the  Sigur  Ghat,  near  Ootacamund,  and  examined  the 
mosquitoes  there  in  the  hope  of  finding  within  them  parasites  like  those  of 
malaria  in  man.  The  results  were  practically  worthless  (except  that  I 
observed  a  new  kind  of  mosquito  with  spotted  wings);  and  I  saw  that  I 
must  return  to  the  exact  methods  laid  down  by  Manson.  The  experiments 
with  the  two  commonest  kinds  of  Culex  were  once  more  repeated — only  to 
prove  once  more  negative.  The  insects,  fed  mostly  on  cases  containing 
the  crescentic  gametocytes  of  Hcemomenas  prcBcox,  were  examined  cell  by 
cell — not  even  their  excrement  being  neglected.  Although  they  were  known 
to  have  swallowed  Haemamoebidae,  no  living  parasites  like  these  could  be 
detected  in  their  tissues — the  ingested  Haemamoebidae  had  in  fact  perished  in 
the  stomach-cavity  of  the  insects.  I  began  to  ask  whether  after  all  there 
was  not  some  flaw  in  Manson's  induction;  but  no — I  still  felt  his  conclusion 
to  be  an  inevitable  one.  And  it  was  at  this  moment  that  good  fortune  gave 
me  what  I  was  in  search  of. 

"  In  a  collecting-bottle  full  of  larvae  brought  in  by  a  native  from  unknown 


Insects  and  Disease  623 

source  I  found  a  number  of  newly  hatched  mosquitoes  like  those  first  observed 
by  me  in  Sigur  Ghat — namely,  mosquitoes  with  spotted  wings  and  hoat-sha ped 
eggs.  Eight  of  these  were  fed  on  a  patient  whose  blood  contained  crescentic 
gametocytes.  Unfortunately  I  dissected  six  of  them  either  prematurely  or 
otherwise  unsatisfactorily.  The  seventh  was  examined,  on  August  20,  cell 
by  cell ;  the  tissues  of  the  stomach  (which  was  now  empty  owing  to  the  meal 
of  malarial  blood  taken  by  the  insect  four  days  previously  being  digested) 
were  reserved  to  the  last.  On  turning  to  this  organ  I  was  struck  by  observ- 
ing, scattered  on  its  outer  surface,  certain  oval  or  round  cells  of  about  two 
or  three  times  the  diameter  of  a  red  blood-corpuscle — cells  which  I  had  never 
before  seen  in  any  of  the  hundreds  of  mosquitoes  examined  by  me.  My 
surprise  was  complete  when  I  next  detected  within  each  of  these  cells  a  jew 
grannies  of  the  characteristic  coal-black  melanin  of  malarial  Jever — a  substance 
quite  unlike  anything  usually  found  in  mosquitoes.  Next  day  the  last  of  the 
remaining  spotted-winged  mosquitoes  was  dissected.  It  contained  precisely 
similar  cells,  each  of  which  possessed  the  same  melanin;  only  the  cells  in 
the  second  mosquito  were  somewhat  larger  than  those  in  the  first. 

"These  fortunate  observations  practically  solve  the  malarial  problem. 
As  a  matter  of  fact,  the  cells  were  the  zygotes  of  the  parasite  oj  remittent  jever 
growing  in  the  tissues  oj  the  gnat;  and  the  gnat  with  spotted  wings  and  boat- 
shaped  eggs  in  which  I  had  found  them  belonged  (as  I  subsequently  ascer- 
tained) to  the  genus  Anopheles.  Of  course  it  was  impossible  absolutely 
to  prove  at  the  time,  on  the  strength  of  these  two  observations  alone,  that  the 
cells  found  by  me  in  the  gnats  were  indeed  derived  from  Hasmamcebidae 
sucked  up  by  the  insects  in  the  blood  of  the  patients  on  whom  they  had 
been  fed — this  proof  was  obtained  by  subsequent  investigations  of  mine; 
but,  guided  by  the  presence  of  the  typical  and  almost  unique  melanin  in  the 
cells,  and  by  numerous  other  circumstances,  I  myself  had  no  doubt  of  the 
fact.  The  clue  was  obtained;  it  was  necessary  only  to  follow  it  up — an 
easy  matter.  .  .  . 

"Early  in  1898,  mainly  through  the  influence  of  Dr.  Manson,  Sir  H.  W. 
Bliss,  and  the  United  Planters'  Association  of  Southern  India,  I  was  placed  by 
the  Government  of  India  on  special  duty  in  Calcutta  to  continue  my  inves- 
tigations. Unable  to  work  with  human  malaria — chiefly  on  account  of  the 
plague-scare  in  Calcutta — I  turned  my  attention  to  the  Hgemamoebidae  of 
birds.  Birds  have  at  least  two  species  of  Haemamoebidaj.  I  subjected  a 
number  of  birds  containing  one  or  the  other  of  these  parasites  to  the  bites 
of  various  species  of  mosquitoes.  The  result  was  a  repetition  of  that  pre- 
viously obtained  with  the  human  parasites.  Pigmented  cells  prec  sely  simi- 
lar to  those  seen  in  the  Anopheles  were  found  to  appear  in  gnats  of  the  species 
called  Culex  jatigans  Wiedemann,  when  these  had  been  fed  on  sparrows  and 
larks  containing  Hcemamceba  relicta.     On  the  other  hand,  these  cells  were 


624  Insects  and  Disease 

never  found  in  insects  of  the  same  species  when  fed  on  healthy  birds  or  on 
birds  containing  the  other  parasite,  called  Hmnamoeba  danilewskii . 

"  It  will  be  evident  that  this  fact  was  the  crucial  test  both  as  regards  the 
parastic  nature  of  these  cells  and  as  regards  their  development  from  the 
hsemocytozoa  of  the  birds;  and  it  was  not  accepted  by  me  without  very  close 
and  laborious  experiment.     The  actual  results  obtained  were  as  follows: 

"Out  of  245  Culex  jatigans  fed  on  birds  containing  il.  relicta  178,  or  72 
per  cent.,  contained  'pigmented  cells.'  But,  out  of  41  Cuhx  jatigans 
fed  on  a  man  containing  crescentic  gametocytes,  5  on  a  man  containing  imma- 
ture tertian  parasites,  154  on  birds  containing  H.  danilewskii,  25  on  healthy 
sparrows,  and  24  on  birds  with  immature  H.  relicta — or  a  total  of  249  insects,, 
all  carefully  examined — not  one  contained  a  single  'pigmented  cell.' 

"Another  experiment  was  as  follows:  Three  sparrows,  one  containing 
no  parasites,  another  containing  a  moderate  number  of  H.  relicta,  and  the 
third  containing  numerous  H.  relicta,  were  placed  in  separate  cages  within 
three  separate  mosquito-curtains.  A  number  of  Culex  Jatigans,  all  bred 
simultaneously  from  larvae  in  the  same  breeding-bottle,  were  now  liberated 
on  the  same  evening  partly  within  the  first  mosquito-netting,  partly  within 
the  second,  and  partly  within  the  third.  Next  morning  many  of  these  gnats 
were  found  to  have  fed  themselves  on  the  birds  during  the  night.  Ten  of 
each  lot  of  gnats  were  dissected  after  a  few  days,  with  the  following  result: 

"The  ten  gnats  fed  on  the  healthy  sparrow  contained  no 'pigmented 
cells.'  The  ten  gnats  fed  on  the  sparrow  with  a  moderate  number  of  para- 
sites were  found  to  contain  altogether  202  'pigmented  cells,'  or  an  average 
of  29  in  each  gnat.  The  ten  gnats  fed  on  the  sparrow  with  numerous  parasites 
contained  1009  'pigmented  cells,'  or  an  average  of  100  cells  in  each  gnat. 
These  thirty  specimens  were  sent  to  Manson  in  England,  who  made  a  similar 
count  of  the  cells. 

"  I  may  mention  one  more  out  of  several  experiments  of  the  same  kind. 
A  stock  of  Culex  jatigans,  all  bred  from  the  larva,  were  fed  on  the  same 
night  partly  on  two  sparrows  containing  H.  relicta,  and  partly  on  a  crow 
containing  H.  danilewskii  (placed,  of  course,  under  separate  mosquito- 
nettings).  Out  of  23  of  the  former  lot,  22  were  found  to  have  pigmented 
cells;   while  out  of  16  of  the  latter,  none  had  them. 

"Hence  no  doubt  remained  that  the  'pigmented  cells'  really  constitute 
a  developmental  stage  in  the  mosquito  of  these  parasites;  and  this  view 
was  accepted  both  by  Laveran  and  Manson,  to  whom  specimens  had  been 
sent.  In  June,  1898,  Manson  published  an  illustrated  paper  concerning 
my  researches,  and  showed  that  the  pigmented  cells  must  in  fact  be  the 
zygotes  resulting  from  the  process  of  fertilization  discovered  by  MacCallum. 

' '  It  remained  to  follow  out  the  life-history  of  the  zygotes.  For  this  purpose 
it  was  immaterial  whether  I  worked  with  the  avian  or  the  human  parasites^ 


Insects  and  Disease  625 

since  these  are  so  extremely  like  each  other.  I  elected  to  work  with  the 
avian  species,  chiefly  because  the  plague-scare  in  Bengal  still  rendered  obser- 
vations with  the  human  species  almost  impossible.  By  feeding  Culex 
jatigans  on  b^rds  with  H.  relicla  and  then  examining  the  insects  one,  two, 
three  or  more  days  afterwards,  it  was  easy  to  trace  the  gradual  growth  of 
the  zygotes.  Their  development  briefly  is  as  follows:  After  the  fertilization 
of  the  macrogamete  has  taken  place  in  the  stomach-cavity  of  the  gnat,  the 
fertilized  parasite  or  zygote  has  the  power  of  working  its  way  through  the 
mass  of  blood  contained  in  the  stomach,  of  penetrating  the  wall  of  the  organ, 
and  of  affixing  itself  on,  or  just  under,  its  outer  coat.  Here  it  first  appears 
about  thirty-six  hours  after  the  insect  was  fed,  and  is  found  as  a  'pigmented 
cell' — that  is,  a  little  oval  body,  about  the  size  of  a  large  red  corpuscle,  and 
containing  the  granules  of  melanin  possessed  by  the  parent  gametocyte 
from  which  the  macrogamete  originally  proceeded.  In  this  position  it  shows 
no  sign  of  movement,  but  begins  to  grow  rapidly,  to  acquire  a  thickened 
capsule,  and  to  project  from  the  outer  wall  of  the  stomach,  to  which  it  is 
attached,  into  the  body-cavity  of  the  insect-host.  At  the  end  of  s  x  days,  if 
the  temperature  of  the  air  be  sufficiently  high  (about  80°  F.),  the  diameter 
of  the  zygote  has  increased  to  about  eight  times  what  it  was  at  first;  that  is, 
to  about  60  microns.  If  the  stomach  of  an  infected  insect  be  extracted  at 
this  stage,  it  can  be  seen,  by  a  low  power  of  the  microscope,  to  be  studded 
with  a  number  of  attached  spheres,  which  have  something  of  the  appear- 
ance of  warts  on  a  finger.  These  are  the  large  zygotes,  which  have  now 
reached  maturity  and  which  project  prominently  into  the  mosquito's  body- 
cavity. 

"All  this  could  be  ascertained  with  facility  by  the  method  I  have  men- 
tioned: and  it  should  be  understood  that  gnats  can  be  kept  alive  for  weeks 
or  even  months  by  feeding  them  every  few  days  on  blood,  or,  as  Bancroft 
does,  on  bananas.  But  a  most  important  point  still  required  study.  What 
happens  after  the  zygotes  reach  maturity?  I  found  that  each  zygote  as 
it  increases  in  size  divides  into  meres,  each  of  which  next  becomes  a  hlastophore 
carrying  a  number  of  blasts  attached  to  its  surface.  Finally,  the  blastophore 
vanishes,  leaving  the  thick  capsule  of  the  zygote  packed  with  thousands 
of  the  blasts.  The  capsule  now  ruptures,  and  allows  the  blasts  to  escape 
into  the  body-fluids  of  the  insect. 

"These  blasts,  when  mature,  are  seen  to  be  minute  filamentous  bodies, 
about  i2-6fi  in  length,  of  extreme  delicacy,  and  somewhat  spindle-shaped — 
that  is,  tapering  at  each  extremity.  Prof.  Herdman  and  I  have  adopted 
this  word  'blast'  for  these  bodies  after  careful  consideration,  but  others 
prefer  other  names.  They  are,  of  course,  spores;  but  spores  which  have 
been  produced  by  a  previous  sexual  process,  and  are  in  fact  the  result  of 
a  kind  of  polembryony.      Just  as  a  fertilized  ovum    gives  rise  to  blasts, 


626  Insects  and  Disease 

which  produce  the  cluster  of  cells  constituting  a  multicellular  animal,  so, 
in  this  case,  the  fertilized  ovum,  or  zygote,  gives  rise  to  blasts,  each  of 
which,  however,  becomes  a  separate  animal.  Prof.  Ray  Lankester  suggests 
for  the  blasts  of  the   Haemamoebidae  the  simple  term  'fiUform  young.' 

"At  this  point  the  investigations  took  a  turn  of  extreme  interest  and 
importance,  scarcely  second  even  to  that  attached  to  the  first  study  of  the 
zygotes.  Since  the  blasts  are  evidently  the  progeny  of  the  zygotes,  they 
must  carry  on  the  life-history  of  the  parasites  to  a  further  stage.  How  do  they 
do  so?  What  is  their  function?  Do  they  escape  from  the  mosquito,  and 
in  some  manner,  direct  or  indirect,  set  up  infection  in  healthy  men  or  birds? 
Or,  if  not,  what  other  purpose  do  they  subserve?  It  was  evident  that  our 
knowledge  of  the  mode  of  infection  in  malarial  fever — and  perhaps  even 
the  prevention  of  the  disease — depended  on  a  reply  to  these  questions. 

"As  I  have  said,  the  zygotes  become  ripe  and  rupture  about  a  week 
after  the  insect  was  first  infected — scattering  the  blasts  into  the  body-cavity 
of  the  host.  What  happens  next?  It  was  next  seen  that  by  some  process, 
apparently  owing  to  the  circulation  of  the  insect's  body-fluids  (for  the  blasts 
themselves  appear  to  be  almost  without  movement),  these  little  bodies  find 
their  way  into  every  part  of  the  mosquito — into  the  juices  of  its  head,  thorax, 
and  even  legs.  Beyond  this  it  was  difficult  to  go.  All  theory — at  least  all 
theory  which  I  felt  I  could  depend  upon — had  been  long  left  behind,  and 
I  could  rely  only  on  direct  observation.  Gnat  after  gnat  was  sacrificed  in 
the  attempt  to  follow  these  bodies.  At  last,  while  examining  the  head  and 
thorax  of  one  insect,  I  found  a  large  gland  consisting  of  a  central  duct  sur- 
rounded by  large  grape-like  cells.  My  astonishment  was  great  when  I 
found  that  many  of  these  cells  were  closely  packed  with  the  blasts  (which 
I  may  add  are  not  in  the  least  like  any  normal  structures  in  the  mosquito). 
Now  I  did  not  know  at  that  time  what  this  gland  was.  It  was  speedily 
found,  however,  to  be  a  large  racemose  gland  consisting  of  six  lobes,  three 
lying  in  each  side  of  the  insect's  neck.  The  ducts  of  the  lobes  finally  unite 
in  a  common  channel  which  runs  along  the  under  surface  of  the  head  and 
enters  the  middle  stylet,  or  lancet,  of  the  insect's  proboscis. 

"It  was  impossible  to  avoid  the  obvious  conclusion.  Observation  after 
observation  always  showed  that  the  blasts  invariably  collect  within  the  cells 
of  this  gland.  It  is  the  salivary  or  poison  gland  of  the  insect,  similar  to  the 
salivary  gland  found  in  many  insects,  the  function  of  which,  in  the  gnat, 
had  already  been  discovered — although  I  was  not  aware  of  the  fact.  The 
function  is  to  secrete  the  fluid  which  is  injected  by  the  insect  when  it  punc- 
tures the  skin — the  fluid  which  causes  the  well-known  irritation  of  the  punc- 
ture, and  which  is  probably  meant  either  to  prevent  the  contraction  of  the 
torn  capillaries  or  the  coagulation  of  the  ingested  blood.  The  position  of 
the  blasts  in  the  cells  of  this  gland  could  have  only  one  interpretation — 


Insects  and  Disease  627 

wonderful  as  that  interpretation  is.  The  blast  must  evidently  pass  down 
the  ducts  of  the  salivary  gland  into  the  wound  made  by  the  proboscis  of 
the  insect,  and  thus  cause  infection  in  a  fresh  vertebrate  host. 

"  That  this  actually  happens  could,  fortunately,  be  proved  without  difficulty. 
As  I  had  now  been  studying  the  parasites  of  birds  for  some  months,  I  possess 
a  number  of  birds  of  different  species,  the  blood  of  which  I  had  examined 
from  time  to  time  (by  pricking  the  toes  with  a  fine  needle).  Some  of  them 
were  infected,  and  some,  of  course,  were  not.  Out  of  in  wild  sparrows 
examined  by  me  in  Calcutta,  I  had  found  H.  relicta — the  parasite  which  I 
had  just  cultivated  in  Culex  jatigans — in  15,  or  13.5  per  cent.  As  a  rule, 
non-infected  birds  were  released;  but  I  generally  kept  a  few  for  the  control 
experiments  mentioned  above,  and  the  blood  of  these  birds  had  consequently 
been  examined  on  several  occasions,  and  had  always  been  found  free  from 
parasites.  At  the  end  of  June  I  possessed  five  of  these  healthy  control  birds — 
four  sparrows  and  one  weaver-bird.  All  of  them  were  now  carefully  examined 
again  and  found  healthy.  They  were  placed  in  their  cages  within  mosquito- 
nets,  and  at  the  same  time  a  large  stock  of  old  infected  mosquitoes  were 
released  within  the  same  nets.  By  'old  infected  mosquitoes'  I  mean 
mosquitoes  which  had  been  previously  repeatedly  fed  on  infected  birds, 
and  many  of  which  on  dissection  had  been  shown  to  have  a  very  large  number 
of  blasts  in  their  salivary  glands.  Next  morning  numbers  of  these  infected 
gnats  were  found  gorged  with  blood,  proving  that  they  had  indeed  bitten 
the  healthy  birds  during  the  night.  The  operation  was  repeated  on  several 
succeeding  nights,  until  each  bird  had  probably  been  bitten  by  at  least  a 
dozen  of  the  mosquitoes.  On  July  9  the  blood  of  the  birds  was  examined 
again.  I  scarcely  expected  any  result  so  complete  and  decisive.  Every 
one  of  the  five  birds  was  now  found  to  contain  parasites — and  not  merely 
to  contain  them,  but  to  possess  such  immense  numbers  of  them  as  I  had 
never  before  seen  in  any  bird  (with  H.  relicta)  in  India.  While  wild  sparrows 
in  Calcutta  seldom  contain  more  than  one  parasite  in  every  field  of  the  micro- 
scope, those  which  I  had  just  succeeded  in  infecting  contained  ten,  fifteen, 
and  even  more  in  each  field — a  fact  due  probably  to  the  infecting  gnats 
having  been  previously  fed  over  and  over  again  on  infected  birds,  a  thing 
which  can  rarely  happen  in  nature. 

"The  experiment  was  repeated  many  times — generally  on  two  or  three 
healthy  birds  put  together.  But  now  I  improved  on  the  original  experiment 
by  also  employing  controls  in  the  following  manner :  A  stock  of  wild  sparrows 
would  be  examined,  and  the  infected  birds  eliminated.  The  remainder 
would  then  be  kept  apart,  and  at  night  would  be  carefully  excluded  from 
the  bites  of  gnats  by  being  placed  within  mosquito-nets.  These  constituted 
my  stock  of  healthy  birds.  From  time  to  time  two  or  three  of  these  would 
be  separated,   examined  again  to  insure  their  being  absolutely   free  from 


628  Insects  and  Disease 

parasites,  and  then  subjected  to  the  bites  of  'old  infected  mosquitoes,' 
and,  of  course,  kept  apart  afterwards  for  daily  study.  Thus  my  stock  of 
healthy  birds  was  also  my  stock  of  control  birds.  Until  they  were  bitten 
by  gnats,  I  found  that  they  never  became  infected  (except  in  a  single  case 
in  which  I  think  I  had  overlooked  the  parasites  on  the  first  occasion),  although 
large  numbers  of  healthy  birds  were  kept  in  this  manner.  The  results  in 
the  case  of  the  sparrows  which  were  subjected  to  the  bite  of  the  infected  gnats 
were  different,  indeed.  Out  of  28  of  these,  dealt  with  from  time  to  time, 
no  less  than  22,  or  79  per  cent.,  became  infected  in  from  five  to  eight  days. 
And,  as  in  the  first  experiment,  all  the  infected  birds  finally  contained  very 
numerous  parasites. 

' '  It  was  most  interesting  to  watch  the  gradual  development  of  the  parasitic 
invasion  in  these  birds;  and  this  development  presented  such  constant 
characters  that,  apart  from  other  reasons,  it  was  quite  impossible  to  doubt 
that  the  infection  was  really  caused  by  mosquitoes.  The  course  of  events 
was  always  as  follows:  The  blood  would  remain  entirely  free  from  parasites 
for  four,  five,  six,  or  even  seven  days.  Next  day  one  or  perhaps  two  parasites 
would  be  found  in  a  whole  specimen.  The  following  day  it  was  invariably 
observed  that  the  number  of  organisms  had  largely  increased;  and  this 
increase  continued  until  in  a  few  days  immense  numbers  were  present — so 
that,  finally,  I  often  observed  as  many  as  seven  distinct  parasites  contained 
within  a  single  corpuscle!  Later  on  many  of  the  birds  died;  and  their 
organs  were  found  to  be  loaded  with  the  characteristic  melanin  of  malarial 
fever. 

"I  also  succeeded  in  infecting  on  a  second  trial  one  of  the  six  sparrows 
which  had  escaped  the  first  experiment;  and  also  a  crow  and  four  weaver- 
birds;  and,  lastly,  gave  a  new  and  more  copious  infection  to  four  sparrows 
which  had  previously  contained  only  a  few  parasites. 

"These  experiments  completed  the  original  and  fundamental  observa- 
tions on  the  life-history  of  the  Hsemamoebidae  in  mosquitoes.  The  parasites 
had  been  carried  from  the  vertebrate  host  into  the  gnat,  and  had  finally 
been  carried  back  from  the  gnat  to  the  vertebrate  host.  The  theories  of 
King,  Laveran,  Koch,  and  Bignami,  and  the  great  induction  of  Manson, 
were  justified  by  the  event :  and  I  have  given  a  detailed  historical  and  critical 
account  of  these  theories,  and  of  my  own  difficulties,  in  the  hope  of  bringing 
conviction  to  those  who  might  perhaps  otherwise  think  the  story  to  be  too 
wonderful  for  credence." 

Since  Ross's  work,  a  host  of  new  observations  and  facts  have  been  made 
known  by  various  investigators.  All  of  these  studies  only  add  to  the  cer- 
tainty that  the  malaria  parasite  depends  absolutely  upon  mosquitoes  for 
its  full  development  and  for  its  dissemination.  Many  of  these  observations 
and  experiments  have  to  do  with  actual  tests  of  malaria  prevention.     Con- 


Insects  and  Disease  629 

spicuous  among  these  tests  was  that  of  two  EngHsh  physicians,  Sambon  and 
Low,  in  1900,  in  the  "  malaria- house "  in  the  Roman  Campagna.  This  ex- 
periment is  described  by  Howard  as  follows:  "Doctors  Sambon  and  Low  had 
constructed  a  comfortable  little  five-roomed  wooden  house  about  three  hours' 
drive  from  Ostia,  in  one  of  the  most  malarious  portions  of  the  Campagna. 
The  house  was  tightly  built  and  was  thoroughly  screened.  The  experi- 
menters lived  in  this  house  through  the  period  when  malaria  is  most  prevalent. 
They  took  no  quinine  and  no  health  precautions  beyond  the  fact  that  at 
sundown  each  day  they  entered  the  house  and  remained  there  until  day- 
light the  next  morning.  Dr.  Rees,  of  the  London  School,  visited  them 
and  occupied  the  house  with  them  for  a  portion  of  the  time,  and  all  three 
conducted  laboratory  work  in  one  of  the  rooms,  which  was  fully  equipped 
for  such  a  purpose,  and  led  a  busy  and  contented  life.  They  visited  the 
neighboring  villages  and  investigated  outbreaks  of  the  fever  in  men  and 
cattle.  They  received  and  entertained  many  visitors  who  were  interested 
in  the  experiment.  They  turned  indoors  before  six  o'clock  and  then  stood 
at  the  windows  and  timed  the  first  appearance  of  Anopheles,  which  would 
come  at  a  certain  hour  each  evening  and  try  to  enter  the  screened  windows 
and  doors.  As  Dr.  Rees  expressed  it,  'It  must  have  been  very  tantalizing 
for  them  to  be  unable  to  get  at  us.'  When  the  rains  set  in,  every  one  said 
that  that  was  the  critical  time  of  the  experiment.  The  people  in  the  sur- 
rounding country  generally  became  feverish  and  ill,  which  meant  simply 
that  they  were  all  full  of  malaria,  and  the  chilling  caused  by  the  rain  brought 
about  an  explosion  of  the  fever.  The  experimenters,  however,  went  out 
into  the  rain  and  got  soaked  to  the  skin,  but  their  health  remained  perfect. 
Not  the  slightest  trace  of  malaria  developed  in  either  of  them;  as  above 
stated,  the  spot  where  the  house  was  built  was  probably  the  most  malarious 
one  in  the  whole  Campagna,  and  it  was  situated  on  the  banks  of  one  of  the 
canals,  which  was  literally  swarming  with  Anopheles  larvae.  The  prevalent 
idea  that  the  night  air  of  the  Campagna  is  in  itself  so  dangerous  was  included 
in  the  experiments,  and  the  windows  were  always  left  open  at  night,  so  that 
if  the  marsh  air  had  anything  to  do  with  malaria  they  would  have  contracted  it 
"  A  check  experiment  was  carried  on  at  the  same  time.  Anopheles 
mosquitoes  which  had  been  fed  on  the  blood  of  a  sufferer  from  malaria  in 
Rome,  under  the  direction  of  the  Italian  authority  Bastianelli,  were  sent 
to  London  early  in  July.  A  son  of  Dr.  Patrick  Manson,  the  famous  inves- 
tigator who  first  proved  the  transfer  of  filariae  by  mosquitoes,  offered  himself 
as  a  subject  for  experiment,  and  allowed  himself  to  be  bitten  by  the  mosquitoes. 
He  had  never  been  in  a  malarious  country  since  he  was  a  child,  but  in  due 
time  was  taken  with  a  well-marked  malarial  infection  of  the  double  tertian 
type,  and  microscopical  examination  showed  the  presence  of  numerous  para- 
sites in  his  blood." 


630  Insects  and  Disease 

Another  test  in  the  same  year  was  made  by  Professor  Grassi  near  Salerno. 
"The  objects  of  this  experiment  were,"  writes  Howard,  "(i)  to  afford 
absolute  proof  of  the  fact  that  malaria  is  transmitted  exclusively  by  the 
bite  of  Anopheles  mosquitoes;  (2)  to  found,  on  the  results  of  recent  research^ 
a  code  of  rules  to  be  adopted  for  freeing  Italy  from  malaria  in  a  few  years. 
The  experiment  consisted  in  protecting  from  malaria  railway  employees 
and  their  families,  living  in  ten  cottages,  at  the  stations  of  St.  Nicolo,  Var- 
co,  and  Albanella,  situated  along  the  Battipaglia-Reggio  Railway,  They 
numbered  one  hundred  and  four  persons,  including  thirty-three  children 
under  ten  years  of  age.  Of  these  one  hundred  and  four  individuals,  at 
least  eleven,  including  four  children,  had  never  suffered  from  the  disease, 
not  having  previously  lived  in  a  malarious  district;  a  certain  number,  it 
appeared,  had  not  suffered  from  it  in  two  or  three  years,  and  all  the  others, 
that  is  to  say,  the  large  majority,  had  suffered  from  it  during  the  last  malarial 
season,  some  of  them  even  in  the  winter.  During  the  malarial  season  the 
health  of  the  protected  individuals  was  good,  with  the  exception  of  a  few 
cases  of  bronchitis  and  a  case  of  acute  gastro-enteritis.  None  of  these  cases 
was  treated  with  quinine.  The  one  hundred  and  four  persons,  with  three 
exceptions,  had  remained  free  from  malaria  up  to  September  i6th,  the  date 
of  the  report." 

These  two  experiments  alone  would  be  conclusive.  Since  1900,  however, 
the  brilliantly  successful  results  of  actual  practical  measures  undertaken 
on  a  large  scale  in  Africa  under  the  supervision  of  English  experts,  and  in 
many  European  and  American  localities  by  army,  governmental,  and  munici- 
pal authorities,  have  settled  the  matter  of  malaria  infection  for  all  time. 
It  only  remains  now  to  adopt  in  medical  practice  everywhere  and  in  the  work 
of  boards  of  health,  other  municipal  and  country  boards  of  supervision,  the 
efficacious  methods,  well  proved,  of  fighting  malaria  by  fighting  mosquitoes. 
An  account  of  some  of  these  methods,  together  with  the  facts  of  the  life-history 
of  mosquitoes,  and  information  regarding  the  distinguishing  characters 
of  the  malaria-bearers  (Anopheles)  and  the  non-malarial  kinds  (Culex  and 
others),  are  given  on  pp.  305  et  seq.  of  this  book.  In  addition  I  may  simply 
say,  when  in  malarial  regions  avoid  the  bite  of  a  mosquito  as  you  would  that 
of  a  rattlesnake.     One  can  be  quite  as  serious  in  its  results  as  the  other. 

Mosquitoes  and  yellow  fever. — So  much  space  has  been  given  to  the 
account  of  the  relation  of  mosquitoes  to  the  propagation  and  dissemination 
of  malaria  that  we  can  do  only  scant  justice  to  the  mosquitoes  in  their  role 
as  disseminators  of  other  diseases. 

Although  yellow  fever  is  a  plague  long  known  and  one  much  studied, 
so  that  its  diagnosis  and  its  treatment  are  well  understood  and  are  the  neces- 
sary knowledge  of  every  physician  practicing  in  tropical  regions,  and  although 
we  know  certainly  that  it  is  the  result  of  the  growth  in  the  body  of  a  parasitic 


Insects  and  Disease  631 

organism,  and  that  this  organism  is  disseminated  by  mosquitoes,  infection 
being  accomplished  only  by  the  puncture  of  a  mosquito,  it  is  a  curious  fact 
that  the  causative  germ  or  parasite  has  not  yet  been  isolated ;  in  other  words, 
is  not  yet  specifically  known.  Whether  bacterium  or  sporozoon,  whether 
inhabiting  the  blood  solely  or  occurring  also  in  other  tissues,  answers  to 
these  questions  remain  to  be  discovered.  Numerous  claims  have  been  made 
by  various  physicians  of  the  discovery  of  the  parasite;  the  latest  claim  has 
been  published  within  the  last  few  months,  but  so  far  none  of  these  reputed 
determinations  of  the  yellow-fever  parasite  has  been  proved  to  the  satisfac- 
tion of  scientific  men.  That  the  yellow-fever  germ,  whatever  it  is,  is  how- 
ever actually  carried  by  mosquitoes,  and  apparently  in  no  other  way,  and  that 
the  dissemination  of  the  disease  thus  depends  upon  the  intervention  and  aid 
of  mosquitoes,  are  facts  that  have  been  proved  largely  through  the  able  and 
courageous  work  of  American  investigators. 

An  early  suggestion  that  mosquitoes  might  be  the  agents  in  spreading 
yellow  fever  came  from  an  Havana  physician.  Dr.  Carlos  Finlay.  His 
theory  was  based  chiefly  on  observations  of  the  correspondence  between 
an  abundance  of  mosquitoes  and  a  period  of  increase  of  yellow  fever.  In 
1900  an  Army  Yellow  Fever  Commission,  composed  of  Major  Walter  C.  Reed, 
surgeon,  U.  S.  A.,  and  three  acting  assistant  surgeons  was  appointed  by 
Surgeon- General  Sternberg  to  investigate  the  disease.  Two  members  of 
the  Commission,  Major  Reed  and  Dr.  Lazear,  lost  their  lives  from  the  attacks 
of  the  disease  they  were  studying.  The  Commission  was  soon  able  to  report 
that  yellow  fever  followed  the  bite  of  mosquitoes  of  the  species  Stegoniyia 
jasciata,  after  the  mosquitoes  had  first  been  allowed  to  suck  blood  from 
yellow-fever  patients.  Soon  after  it  was  able  to  report  that  yellow  fever  did 
not  follow  as  a  result  of  exposing  non-immune  subjects  to  contact  with  clothes 
or  bedding  or  other  belongings  of  patients  actually  suffering  and  dying  from 
yellow  fever.  On  the  basis  of  these  discoveries  the  Commission  made  certain 
crucial  experiments  whose  outcome  is  convincing  proof  of  the  facts  of  the 
transmission  of  the  disease  by  mosquitoes,  and  that  it  is  transmitted  in  no 
other  way. 

A  small  house  was  built,  thoroughly  screened  against  mosquitoes.  In 
this  house  seven  non-immune  persons  lived  during  sixty-three  days;  three 
of  them  occupied  the  room  each  night  for  twenty  days,  sleeping  on  sheets, 
pillow-cases,  and  blankets  brought  from  beds  occupied  by  yellow-fever  patients 
in  Havana,  soiled  by  their  discharges.  Some  of  the  bedding  and  clothing  worn 
by  the  subjects  in  the  yellow-fever  house  were  purposely  infected  with  the 
discharges  of  a  fatal  case  of  yellow  fever.  During  all  the  sixty-three  days  the 
average  temperature  of  the  house  was  kept  at  76.2°  F.,  a  considerable  amount 
of  humidity  was  maintained,  and  little  sunlight  or  freely  circulating  air  was 
admitted,  all  of  these  conditions  being  highly  favorable  for  the  development 


632  Insects  and  Disease 

of  yellow  fever.     Not  a  single  one  of  the  seven  inhabitants  of  the  house  was 
attacked  by  the  disease. 

Another  similar  building  was  erected  near  by,  well  provided  with  doors 
and  windows  for  thorough  ventilation.  It  was  divided  into  two  rooms 
by  a  wire-screen  partition  extending  from  floor  to  ceiling.  All  articles 
admitted  to  the  building  were  carefully  disinfected  by  steam  before  being 
placed  therein.  Into  the  large  room  of  this  building  mosquitoes  which  had 
been  previously  contaminated  by  biting  yellow-fever  patients  were  admitted. 
Non-immunes  were  placed  in  both  rooms.  In  the  room  in  which  mosquitoes 
were  not  admitted  the  experimentalists  remained  in  perfect  health.  In 
the  other  room  six  out  of  seven  persons  bitten  by  infested  mosquitoes  came 
down  with  yellow  fever.  In  all,  of  persons  bitten  by  infested  mosquitoes 
that  had  been  kept  twelve  days  or  more  after  biting  yellow-fever  patients 
before  being  allowed  to  bite  them,  80  per  cent,  were  taken  with  the  disease. 

Other  similar  crucial  tests  were  made  by  the  Commission  and  have  been 
made  by  other  investigators  working  in  other  places.  The  conclusions  are 
positive.  Yellow  fever  is  caused  by  a  germ,  as  yet  undetermined,  which 
lives  for  part  of  its  life  in  the  blood  of  human  beings,  and  is  carried  from 
man  to  man  by  mosquitoes,  being  sucked  up  with  blood  by  mosquitoes  which 
find  access  to  yellow-fever  patients,  and  transmitted  to  the  blood  of  new 
subjects  from  the  beak  during  puncturing.  An  interval  of  about  two  weeks 
after  the  mosquito  is  affected  is  necessary  before  the  mosquito  is  capable 
of  conveying  the  infection,  which  means  that  the  yellow-fever  germ  is  under- 
going a  certain  necessary  part  of  its  development  in  the  mosquito's  body. 

As  I  have  already  mentioned  (p.  308),  the  mosquito  species  Stegomyia 
jasciata,  the  carrier  of  the  yellow  fever  in  the  West  Indies,  is  the  most  abundant 
mosquito  species  in  the  Hawaiian  Islands  and  also  in  the  Samoan  Islands. 
In  neither  of  these  groups  of  tropic  islands  has  yellow  fever  yet  found  a 
footing,  but  is  it  not  possible  that  with  the  cutting  of  the  Panama  Canal  and 
the  direct  passage  of  ships  from  the  West  Indies  to  these  islands,  the  whole 
passage  being  made  within  tropical  regions,  yellow-fever-infested  mosquitoes 
will  be  carried  alive  to  the  Pacific  islands?  It  is  certainly  a  matter  which 
must  receive  scientific  attention. 

Mosquitoes  and  filariasis. — Filariasis  is  the  rather  generic  term  for  a 
number  of  diseases,  or  for  one  disease  which  manifests  itself  in  several  ways, 
due  to  the  presence  in  the  body  of  the  infected  patient  of  filariae  or  thread- 
worms. 

These  organisms  are  of  much  higher  organization  than  the  minute  unicel- 
lular Haemamoebse  that  cause  malaria;  they  belong  to  the  group  of  round- 
worms, the  Nematoda,  and  in  fully  developed  condition  some  species  of 
filariae  are  very  long,  the  notorious  guinea-worm,  Filaria  medinensis,  which 
parasitizes  the  human  body  in  the  tropics  of  the  Old  World,  attaining  a 


Insects  and  Disease  633 

length  of  three  feet.  Other  species  vary  from  an  inch  to  a  foot  in  length. 
All  the  species  of  the  genus  Filaria  are  parasites  of  other  animals  living 
mostly  in  the  stomach  and  intestine,  sometimes  in  the  connecting  tissue  and 
elsewhere  in  the  body.  One  species  lives  in  the  heart  of  dogs,  another  in 
the  body-cavity  of  the  horse,  donkey,  and  ox,  still  another  in  the  eyes  of 
negroes  in  West  Africa,  while  Filaria  hancrojti,  the  particular  species 
which  is  the  cause  of  filariasis,  lives  in  the  blood  and  lymphatic  vessels  of 
men  in  tropic  lands  of  both  Old  and  New  World.  The  young  or  larval 
filariae  (sometimes  called  F.  sangtiinis-hominis)  live  in  the  blood,  but  they 
finally  lodge  in  the  lymphatic  glands  and  there  mature. 

The  most  common  form  of  filariasis  is  called  elephantiasis.  The  presence 
of  the  parasite  in  the  lymphatic  glands  and  vessels  leads  to  a  subcutaneous 
hypertrophy  of  tissue  which  often  results  in  a  most  frightful  malformation 
of  parts  of  the  body.  The  legs  and  arms  are  particularly  affected,  and  such 
a  member  may  become  of  enormous  size  and  be  hideously  repulsive  in  appear- 
ance. A  single  leg  may  come  to  weigh  as  much  as  all  the  rest  of  the  body. 
An  arm  may  become  a  foot  thick,  the  fingers  being  mere  papillar-like  processes 
at  the  end  of  it.  In  Samoa  fully  one-third  of  the  natives  are  attacked  by  this 
disease,  which  is  incurable,  and,  though  slow  in  development  and  nearly 
painless,  certainly  fatal. 

Manson,  to  whose  keen  inductions  much  of  the  credit  for  the  discovery 
of  the  relation  between  the  mosquito  and  malaria  is  due,  was  the  first  to 
suggest,  on  a  basis  of  some  observation  and  special  investigation,  that  the 
mosquito  is  the  secondary  or  intermediate  host  of  the  elephantiasis-producing 
filariae  and  that  the  mosquito  is  probably  responsible  for  the  dissemination 
of  the  disease. 

The  subsequent  researches  of  Manson,  Bancroft,  and  others  have  proved 
that  the  filariae  actually  do  live  in  the  bodies  of  mosquitoes,  being  taken  into 
the  alimentary  canal  with  the  blood  sucked  from  men  affected  by  the  disease. 
These  filariae  work  their  way  through  the  walls  of  the  alimentary  canal  and 
gather  in  the  thoracic  muscles.  Here  they  live  for  some  time,  two  or  three 
weeks  probably,  and  are  then  ready  for  their  further  development  in  the 
blood  and  lymph  of  man.  Exactly  how  this  transfer  is  made  is  not  definitely 
proved  as  yet,  although  much  evidence  has  been  secured  to  show  that  the 
transmission  is  made  by  the  mosquito-bite.  Manson  suggested  that  the 
female  mosquitoes  coming  to  reservoirs,  ponds,  or  puddles  of  water  to  lay 
their  eggs  would  often  die  there  so  that  their  bodies  would  fall  on  to  the  sur- 
face of  the  water.  As  they  disintegrated  by  rapid  decay,  the  larval  filariae  in 
the  thoracic  muscles  would  escape  into  the  water,  and  live  there  until  taken  into 
the  alimentary  canal  of  people  drinking  some  of  the  water  from  the  reservoir 
or  pond.  Bancroft  believes,  however,  that  the  filariae  are  transmitted  by 
the  bite  or  puncture  of  the  mosquito,  and  has  actually  observed  the  migration 


634  Insects  and  Disease 

of  the  filariae  from  the  thoracic  muscles  forward  into  the  head  and  "beak" 
of  the  mosquito.  He  has  seen  a  filaria  larva  issuing  from  a  fine  opening 
near  the  tip  of  the  labium.  According  to  Bancroft's  theory  the  filaria 
escapes  from  the  beak  of  a  puncturing  mosquito  into  the  skin  of  a  man, 
finishes  its  development  and  growth  in  the  skin,  becomes  adult,  pairs  and 
produces  embryos  which  get  into  the  lymphatic  spaces  or  vessels,  and  are 
carried  by  the  lymph  into  the  blood.  Here  they  circulate  over  the  body, 
finally  lodging  in  the  lymphatic  glands  and  causing  the  characteristic  hyper- 
trophy of  tissue.  Further  investigation  is  necessary,  however,  before  the 
question  of  transmission  is  fully  understood.  That  the  mosquito  is  the 
actual  disseminating  agent  of  the  disease  is,  however,  certain. 

The  species  of  mosquito  which  acts  as  intermediate  host  and  distributing 
agent  of  the  filariae  in  Australia  is  Culex  fatigans,  var.  skusii.  Anopheles 
rossii  is  also  known  to  carry  the  filariae.  In  Samoa,  where  elephantiasis 
is  more  prevalent  than  anywhere  else  in  the  world,  I  have  found  the  most 
abundant  mosquito  to  be  Stegomyia  fasciata,  the  same  species  that  spreads 
yellow  fever.  This  species  is  also  the  most  abundant  mosquito  in  the  Hawaiian 
Islands,  and  is  indeed  wide-spread  over  the  tropics  and  subtropics  of  the 
whole  world.  If,  as  is  probable,  it  is  the  principal  carrier  in  Samoa  of  the 
filariae  that  cause  elephantiasis,  it  is  the  most  formidable  single  species  among 
all  the  insect  scourges  of  mankind. 

In  this  brief  account  of  the  role  played  by  certain  insects  in  the  propa- 
gation and  dissemination  of  certain  human  diseases  only  a  small  part  of  the 
story,  as  already  known,  has  been  told.  Cockroaches,  bedbugs,  and  other 
household  insects  are  being  found  to  be  hosts  for  the  germs  of  other  familiar 
diseases.  A  host  of  investigators  is  at  work;  reports  of  discoveries  are  being 
published  constantly,  and  in  a  few  years  our  knowledge  of  this  causal  rela- 
tion of  insects  to  human  disease  will  fill  books  instead  of  chapters. 


APPENDIX 
COLLECTING  AND  REARING  INSECTS 


The  simpler  the  equipment  the  better  for  the  beginning  collector  of 
insects.  A  net,  collecting-bottle,  box  for  pinning  specimens,  papers  for 
"papered"  ones,  a  few  empty  vials  and  pill-boxes,  and  a  few  vials  contain- 
ing 85  per  cent,  alcohol — this  is  outfit  enough  for  general  work.  For  special 
visits  to  ponds  and  brooks,  a  water-  or  dredging-net,  and  a  jar  or  tin  pail  for 
carrying  home  living  specimens,  are  needed.  A  large-bladed  jack-knife 
for  digging  and  prying  under  stones,  cutting  into  logs  and  stumps,  and  split- 
ting canes  and  galls  is  always  useful.  A  pair  of  forceps,  for  handling  sting- 
ing specimens,  and  very  small  or  delicate  ones,  is  convenient. 

The  net  (Fig.  799)  should  be  of  some  strong  non-tearing  cloth  netting — 
bobinet  is  excellent — 12  to  14  inches  in  diam- 
eter at  the  mouth  and  about  24  inches  deep, 
tapering  to  a  rounded  bottom  about  4  to  6  inches 
in  diameter.  The  handle  should  be  light  and 
about  3^  feet  long.  The  wire  ring  supporting 
the  net  should  be  strong — No.  3  galvanized  iron 


Fig.  799.  Fig.  800. 

Fig.  799. — Collecting-net.     (After  Packard.) 

Fig.  800. — Insect-killing  bottle;   cyanide  of  potassium  at  bottom  covered  with  plaster  of 
Paris.     (After  Jenkins  and  Kellogg.) 

wire  is  good — and  firmly  fixed  in  the  handle.     For  a  water-net  the  meshes 
should  be  coarse  and  the  handle,  wire,  and  netting  all  extra  strong. 

The  killing-bottle  (Fig.  800)  is  prepared  by  putting  a  few  small  lumps 
(about  a  teaspoonful)  of  cyanide  of  potassium  into  the  bottom  of  a  wide- 

635 


636  Collecting  and  Rearing  Insects 

mouthed  bottle  from  three  to  six  inches  high  (a  quinine  or  quassia  bottle  is 
good)  and  covering  this  with  wet  plaster  of  Paris.  WTien  the  plaster  sets 
it  will  hold  the  cyanide  in  place,  and  allow  the  fumes  given  off  by  its  gradual 
volatilization  to  fill  the  bottle.  Or  the  cyanide  may  be  covered  with  damp 
sawdust  over  which  is  placed  a  cardboard  disk  cut  so  as  to  fit  tightly  into 
the  bottle.  The  advantage  of  the  sawdust  covering  instead  of  plaster  of 
Paris  is  that  it  allows  one  to  clean  out  the  bottle  after  the  cyanide  is  used 
up  and  to  recharge  it.  The  plaster  of  Paris  is  broken  out  of  a  used-up  bottle 
only  with  difficulty.  The  disadvantage  of  the  sawdust  and  cardboard  cover 
is  that  it  is  likely  to  be  loosened  if  the  bottle  is  jarred  often.  Insects  dropped 
into  a  cyanide  bottle  will  be  killed  in  from  two  to  six  or  seven  minutes.  Keep 
a  little  tissue-paper  in  the  bottle  to  soak  up  moisture  and  to  prevent  the 
specimens  from  rubbing.  Also  keep  the  bottle  well  corked.  Label  it 
"poison,"  and  do  not  breathe  the  fumes  (hydrocyanic  gas).  Insects  may 
be  left  in  it  overnight  without  injury  to  them. 

Butterflies  or  dragon-flies  too  large  to  drop  into  the  killing-bottle  may 
be  killed  by  dropping  a  little  chloroform  or  benzine  on  a  piece  of  cotton, 
to  be  placed  in  a  tight  box  with  them.  Larvae  (caterpillars,  grubs,  etc.) 
and  pupae  (chrysalids)  should  be  dropped  into  the  vials  of  alcohol. 

When  the  collected  insects  are  killed  they  may  be  "pinned  up"  or 
"papered"  in  the  field;  or  if  not  many  have  been  taken,  may  be  brought 
home  in  the  killing-bottle  and  cared  for  after  arriving. 

To  "paper"  specimens — and  only  insects  with  large  wings,  as  butterflies, 
moths,  dragon-flies,  etc.,  are  papered — they  should  have  the  wings  folded 
over  the  back  and  the  specimen  then  laid  on  one  side  on  a  rectangular  piece 
of  smooth  paper,  not  too  soft,  which  is  then  folded  so  as  to  form  a  triangle 
with  the  margins  narrowly  folded  over  to  prevent  its  opening.  A  very  success- 
ful professional  collector  of  my  acquaintance  "papers,"  in  a  sense,  small 
insects  in  the  following  way:  In  the  bottom  of  a  small  tin,  wooden,  or  paste- 
board box  he  puts  a  thin  layer  of  glazed  cotton;  over  it  he  lays  a  sheet  of 
paper,  and  on  this  a  layer  of  small  insects  just  as  they  are  poured  out  of  the 
cyanide  bottle;  then  a  covering  sheet  of  paper,  and  over  this  a  layer  of  cotton, 
another  sheet  of  paper,  a  layer  of  insects,  and  so  on.  In  this  way  he  rapidly 
cares  for  hundreds  or  thousands  of  specimens  in  the  field.  When  these 
specimens  are  brought  home  he  either  pins  them  up  immediately  while 
fresh  and  flexible,  or  stores  them  away  to  be  worked  over  and  pinned  up 
at  leisure.  Before  dried  insects  can  be  pinned,  however,  they  must  be  re- 
laxed. This  may  be  effected  by  steaming  them,  or  simply  by  putting  them 
for  a  day  or  two  into  a  closed  glass  jar  with  a  soaked  sponge.  In  my  lab- 
oratory we  keep  one  or  two  jars  with  a  layer  of  wet  sand  in  the  bottom; 
into  these  relaxing  jars  dried  insects  can  be  put  at  any  time,  and  made  ready 
for  pinning. 


Collecting  and  Rearing  Insects 


637 


To  "pin  up"  specimens  special  insect  pins  are  used.  These  pins  can 
be  bought  of  any  dealer  in  naturalists'  supplies  at  from  ten  to  fifteen  cents 
a  hundred.  Order  Klaeger  pins  No.  3  or  Carlsbaeder  pins  No.  5.  These 
are  the  most  useful  sizes.  For  larger  pins  order  Klaeger  No.  5  (Carls- 
baeder No.  8);  for  smaller  order  Klaeger  No.  i  (Carlsbaeder  No.  2). 
Pin  each  insect  straight  down  through  the  thorax  (Fig.  801)  (except  beetles, 
which  pin  through  the  right  wing-cover  near  the  middle  of  the  body  (Fig. 
802)).  On  each  pin  below  the  insect  place  a  small  label  with  date  and  locality 
of  capture.     If  many  specimens  are  going  to  be  collected  in  one  locality,  small 


Fig.  801.  Fig.  802.  Fig.  803. 

Fig.  801. — Insect  properly  pinned  up.     (Aftei  Jenkins  and  Kellogg.) 
Fig.  802. — Mode  of  pinning  beetle.     (After  Packard.) 
Fig.  803. — Pinning  a  bug.     (After  Packard.) 

"locality  and  date"  labels  printed  in  diamond  or  agate  type  on  paper  not 
too  stifif  for  the  pin  and  yet  not  so  thin  and  weak  as  to  fold  on  the  pin  should 
be  got.  The  following  is  the  kind  of  label  in  use  by  the  students  in  my 
laboratory:  ^*funi9o'^'  For  each  specimen  the  day  of  the  month  and 
year  is  filled  in.  We  have  such  labels  for  each  month  in  the  year.  Insects 
too  small  to  be  pinned  may  be  gummed  on  to  small  slips  of  cardboard,  which 
should  be  then  pinned  up. 

The  box  for  pinned  specimens  which  is  to  be  carried  on  the  collecting 
trip  should  be  small :  a  cigar-box  with  its  bottom  covered  with  sheet  cork 
or  compressed  cork  is  excellent.  Corn  pith  can  be  used;  on  the  Pacific 
coast  the  pith  of  the  flowering  stalk  of  the  century-plant  is  much  used,  under 
the  name  of  pita-wood,  and  is  unusually  good  for  the  purpose.  For  con- 
taining the  specimens  permanently  cigar-boxes  are  only  to  be  used  when 
more  carefully  made  boxes  cannot  be  afforded.  Certain  small  insects, 
especially  beetles  of  the  family  Dermestidse,  have  a  particular  liking  for 
dried  insects  and  work  their  way  into  any  but  the  tightest  of  specimen  boxes. 
If  cigar-boxes  have  to  be  used,  a  small  naphthaline  cone  fastened  on  a  pin 
should  be  kept  in  each  box.  It  will  be  much  safer  to  obtain  tight  boxes 
or  trays,  either  of  the  glass-topped  sort  used  for  display  collections,  or  of 
the  book-shaped  sort,  used  by  the  National  Museum  and  many  other  museums 


638 


Collecting  and  Rearing  Insects 


and  collectors.     These  boxes  may  be  bought  of  dealers  in  naturalists'  sup- 
plies. 

Butterflies,  dragon-flies,  and  other  larger  and  beautiful-winged  insects 
should  be  "spread,"  that  is,  should  be  allowed  to  dry  with  wings  expanded. 
To  do  this  spreading — or  setting — boards  (Figs.  St>4  and  805)  are  necessary. 

Such  a  board  consists  of  two  strips  of  wood 
fastened  a  short  distance  apart  so  as  to 
leave  between  them  a  groove  for  the  body 
of  the  insect,  and  upon  which  the  wings 
are  held  in  position  until  the  insect  is  dry. 
A  narrow  strip  of  pith  or  cork  should  be 
fastened  to  the  lower  side  of  the  two  strips 
of  wood,  closing  the  groove  below.  Into 
this  cork  is  thrust  the  pin  on  which  the 
insect  is  mounted.  Another  strip  of  wood 
is  fastened  to  the  lower  sides  of  the  cleats 
to  which  the  two  strips  are  nailed.  This 
serves  as  a  bottom  and  protects  the  points 
of  the  pins  which  project  through  the  piece 
of  cork.  The  wings  are  held  down,  after 
having   been   outspread   with    the    hinder 


Fig.  804.  Fig.  805. 

Fig.  804.— Setting-board  with  butterflies  properly  spread.     (After  Comstock.) 
Fig.  805.— Setting- board  in  cross-section  to  show  construction.     (After  Comstock.) 

margins  of  the  fore  wings  about  at  right  angles  to  the  body,  by  strips  of  paper 
pinned  down  over  them. 

"Soft  specimens,"  such  as  insect  larvas,  myriapods,  and  spiders,  should 
be  preserved  in  bottles  of  alcohol  (85  per  cent.).  Specimens  which  the 
collector  may  desire  to  preserve  in  condition  fit  for  future  dissecting  should 
be  killed  in  boiling  water,  into  which  they  should  be  dropped  and  allowed 
to  remain  for  a  minute  or  two  until  thoroughly  stiffened,  and  then  removed 
to  50  per  cent,  alcohol  for  six  hours,  and  finally  to  85  per  cent,  alcohol  for 


Collecting  and  Rearing  Insects  639 

preservation.     Nests,  galls,  stems,  and  leaves  partly  eaten  by  insects,  and 
other  dry  specimens  can  be  kept  in  small  pasteboard  boxes. 

Where  and  how  to  collect. — The  principal  points  about  where  and  how- 
to  collect  will  be  obvious  even  to  the  veriest  novice.  Go  where  the  insects 
chiefly  congregate,  and  collect  them  in  the  most  effective  way.  But  some  of 
the  insect  haunts  may  not  be  known  to  the  beginner  nor  at  first  catch  his 
eye,  and  there  are  little  tricks  about  collecting  in  the  most  effective  way. 
"The  most  advantageous  places  for  collecting  are  gardens  and  farms,  the 
borders  of  woods,  and  the  banks  of  streams  and  ponds.  The  deep,  dense 
forests  and  open,  treeless  tracts  are  less  prolific  in  insect  life.  In  winter 
and  early  spring  the  moss  on  the  trunks  of  trees,  when  carefully  shaken 
over  a  newspaper  or  white  cloth,  reveals  many  beetles  and  Hymenoptera. 
In  the  late  summer  and  autumn,  toadstools  and  various  fungi  and  rotten  fruits 
attract  many  insects ;  and  in  early  spring,  when  the  sap  is  running,  we  have 
taken  rare  insects  from  the  stumps  of  freshly  cut  hard-wood  trees.  Wollaston 
says:  'Dead  animals,  partially  dried  bones,  as  well  as  the  skins  of  moles 
and  other  vermin  which  are  ordinarily  hung  up  in  fields,  are  magnificent 
traps  for  Coleoptera;  and  if  any  of  these  be  placed  around  orchards  and 
inclosures  near  at  home,  and  be  examined  every  morning,  various  species 
of  NitiduliE,  Silphidffi,  and  other  insects  of  similar  habits,  are  certain  to  be 
enticed  and  captured.' 

"Planks  and  chippings  of  wood  may  be  hkewise  employed  as  successful 
agents  in  alluring  a  vast  number  of  species  which  might  otherwise  escape 
our  notice;  and  if  these  be  laid  down  in  grassy  places,  and  carefully  inverted 
every  now  and  then  with  as  little  violence  as  possible,  many  insects  will  be 
found  adhering  beneath  them,  especially  after  dewy  nights  and  in  showery 
weather.  Nor  must  we  omit  to  urge  the  importance  of  examining  the  under 
sides  of  stones  in  the  vicinity  of  ants'  nests,  in  which  position,  during  the 
spring  and  summer  months,  many  of  the  rarest  of  our  native  Coleoptera 
may  be  occasionally  procured.  Excrementitious  matter  always  contains 
many  interesting  forms  in  various  stages  of  growth. 

"  The  trunks  of  fallen  and  decaying  trees  offer  a  rich  harvest  for  many 
wood-boring  larvae,  especially  the  Longicorn  beetles; 
and  weevils  can  be  found  in  the  spring,  in  all  stages. 
Numerous  carnivorous  coleopterous  and  dipterous 
larvae  dwell  within  them,  and  other  larvae  which  eat 
the  dust  made  by  the  borers.  The  inside  of  pithy  Fig.  806.— Water  -  net. 
plants,    like   the   elder,    raspberry,    blackberry,   and 

syringa,  is  inhabited  by  many  of  the  wild  bees,  Osmia,  Ceratina,  and  the 
wood-wasps,  Crabro,  Stigmus,  etc.,  the  habits  of  which,  with  those  of  their 
Chalcid  and  Ichneumon  parasites,  offer  endless  amusement  and  material  for 
study. 


640  Collecting  and  Rearing  Insects 

"Ponds  and  streams  shelter  a  vast  throng  of  insects,  and  should  be  dUigently 
dredged  with  the  water-net,  and  stones  and  pebbles  should  be  overturned 
for  aquatic  beetles,  Hemiptera,  and  Dipterous  larvae." 

Much  collecting  may  be  done  at  night.  Many  nocturnal  moths  and 
beetles  are  attracted  by  bright  Hghts:  the  city's  lamp-posts  or  your  own 
briUiant  bicycle-lamp  of  acetylene  gas  may  be  reUed  on.  "Sugaring" 
for  moths  on  warm  nights,  a  favorite  trick  of  moth-collectors,  consists  of 
smearing  a  mixture  of  stale  beer  and  sirup  in  patches  a  foot  square  on  the 
trunks  of  various  trees,  and  then  making  repeated  rounds  of  these  trees 
with  a  dark  lantern.  Throw  the  light  on  the  smeared  spot  and  any  feed- 
ing moth  there  will  tarry  long  enough  to  be  covered  with  a  wide-mouthed 
bottle  or  swooped  up  with  the  net. 

Numerous  small  insects  may  be  found  in  galls,  in  roUed-up  leaves,  and 
in  bored  canes.  Where  a  plant  shows  leaves  ragged  or  full  of  holes,  there 
look  for  the  hole-makers.  In  this  kind  of  insect-hunting  one  is  Hkely  to 
get  the  immature  stages  of  insects  rather  than  the  adult.  So  much  the  better. 
A  collection  should  not  be  limited  to  grown-up  insects  alone,  but  should 
include  eggs,  larvae,  chrysalids,  cocoons,  nests,  and  specimens  of  insect  archi- 
tecture and  industry,  and  specimens  showing  the  character  of  the  injuries 
to  plants  caused  by  insects.  Any  specimen  which  illustrates  anything  of 
the  life,  the  biology,  of  insects  should  go  into  the  collection.  And  everything 
should  be  labeled,  accurately  and  fully.  Locality  and  date,  notes  telling 
of  such  evanescent  conditions  as  color  or  of  such  ecologic  relations  as  character 
of  the  surroundings  should  be  put  on  the  specimen,  or  written  into  a  "  collec- 
tions" book  under  a  number  corresponding  with  one  on  the  specimen.  The 
collecting  of  immature  stages  of  insects  leads  naturally  to  attempts  to  rear 
these  caterpillars,  etc.,  at  home  or  in  the  schoolroom  or  laboratory. 

Rearing  insects. — While  in  ordinary  collecting  the  insects  are  killed 
immediately  after  being  caught,  the  collector  going  afield  to  obtain  specimens 
to  keep  alive  and  rear  must  bring  back  his  trophies  unharmed.  It  is  neces- 
sary that  he  modify  his  field  equipment  somewhat.  He  needs  empty  boxes 
and  little  jars,  more  than  kiUing-bottles  and  cork-lined  pinning-boxes.  Do 
not  trouble  to  punch  air-holes  in  box-lids;  enough  air  will  get  in  through 
cracks  and  loose-fitting  covers.  Aquatic  specimens,  however,  are  easily 
suffocated  by  filling  the  water- jar  too  full  and  then  screwing  a  tight  cover 
on  to  prevent  splashing.  The  jars  and  pails  should  be  carried  uncovered 
if  possible,  and  they  should  be  broad  and  shallow  rather  than  narrow  and 
deep.  Do  not  try  to  bring  too  many  water-insects  back  in  one  jar;  crowd- 
ing is  always  fatal  to  them.  With  log-burrowing  grubs  and  larvae  bring  in 
some  chips  and  dust  of  the  home  log;  with  underground  larvas  bring  in 
some  soil.  Simply  because  you  find  such  larvae  in  a  certain  place  is  sufficient 
proof  that  their  surroundings  are  of  the  right  sort  for  them. 


Collecting  and  Rearing  Insects 


641 


When  brought  home  the  live  specimens  must  be  transferred  to  "cages" 
or  rearing-boxes  or  jars  in  which  proper  food  is  kept  and  which  enables 
the  insect  to  live  as  nearly  as  possible  in  its  normal  way.  We  want  our 
caterpillars  not  merely  to  provide  us  with  fine  "unrubbed"  fresh  moths  and 
butterflies  for  our  collection,  but  want  them  to  go  through  under  our  eyes 
their  usual  life-history:  we  wish  to  see  them  eat  and  crawl  and  moult 
and  spin  and  transform.  We  wish  to  get  acquainted  with  the  details  of 
their  living;    to  watch  them  grow  and  develop;    and  to  see  them  display 


Fig.  807.— Breeding-cage.     (After  Packard.) 


their  instincts  and  insect  wits.  We  may  go  so  far  in  our  scientific  curiosity 
as  to  be  led  to  experimenting  with  them:  to  note  how  they  react  or  behave 
toward  light  and  darkness,  toward  moisture  or  dryness,  heat  or  cold;  to 
see  if  they  may  be  induced  to  modify  their  inherited  instincts  to  the  extent 
of  doing  new  and  unusual  things,  or  old  things  in  new  ways;  to  see  if  their 
life  is  pure  mechanism  or  in  a  simpler  and  more  generalized  way  somethmg 
like  ours,  in  which  consciousness  and  memory  and  choice  play  so  important 

a  part. 

Particularly  available  and  interesting  kinds  of  insects  to  rear  m  home 
cages  and  aquaria  are  the  larvae  (caterpillars)  of  moths  and  butterflies,  various 
leaf-eating,   wood-boring,   and   ground-burrowing  beetle  larvae,  honey-bees 


642 


Collecting  and  Rearing  Insects 


and  ants,  and  many  still-water  insects,  as  water-beetles  and  bugs,  mosquitoes, 
May-flies,  dragon-flies,  etc.  For  these  various  kinds  of  insects  with  their 
various  kinds  of  habitat  and  habit  several  different  kinds  of  cages  are  neces- 
sary. 

For  moths  and  butterfly  larvae  very  simple  cages  are  sufficient.  It  is 
only  necessary  that  they  admit  light  and  air,  that  they  keep  the  insects  in, 
and  that  food,  green  leaves  of  the  favorite  food-plant,  may  be  kept  fresh 
in  them,  or  readily  repeatedly  supplied.  For  small,  or  a  few,  caterpillars  an 
excellent  rearing-cage  is  shown  in  Fig.  808.  It  is  made  by  combining  a 
flower-pot  and  a  lamp-chimney  or  lantern-globe.  When  practicable,  the 
food-plant  of  the  insects  to  be  bred  is  planted  in  the  flower-pot;  in  other 
cases  a  bottle  or  tin  can  filled  with  wet  sand  is  sunk  into  the  soil  in  the  flower- 
pot, and  the  stems  of  the  plant  are  stuck  into  this  wet  sand.  The  top  of 
the  lantern-globe  is  covered  with  Swiss  muslin.  These  breeding-cages 
are  inexpensive,  and  especially  so  when  the  pots  and  globes  are  bought  in 
considerable  quantities. 


Fig. 
Fig. 


Fig.  808. 
808. — Lamp-chimney  and  floor  of  breeding-cage. 
809. — Bell-jar  live-cage. 


Fig.  809. 
(After  Jenkins  and  Kellogg.) 


In  our  laboratory  we  have  made  much  use  of  bell-jars  of  the  kind  with 
a  hole  in  the  top  for  a  cork,  which  can  be  closed  with  netting  instead  of  a 
cork,  so  that  the  air  may  enter  (Fig.  809).  Small  branches  of  the  food- 
plant  are  kept  in  glass  bottles  of  water,  whose  mouth  is  closed  around  the 
branches  by  loose  cotton  so  as  to  prevent  the  caterpillars  from  getting  in 
and  drowning.  For  larger,  airier  cages  in  which  many  caterpillars  or  trans- 
forming pupae  can  be  kept  we  make  much  use  of  common  wire-screened 


Collecting  and  Rearing  Insects 


643 


meat-safes  (Fig.  810),  which  can  be  got  at  the  grocer's  for  about  a  dollar  apiece. 
Comstock  describes  a  good  home-made  cage  built  by  fitting  a  pane  of  glass 
into  one  side  of  an  empty  soap-box.  A  board,  three  or  four  inches  wide, 
should  be  fastened  below  the  glass  so  as  to  admit  of  a  layer  of  soil  being 


Fig.  810. — Meat-safe  live-cage. 

placed  in  the  lower  part  of  the  cage,  and  the  glass  can  be  made  to  slide,  so 
as  to  serve  as  a  door  (Fig.  8ii).  The  glass  should  fit  closely  when  shut, 
to  prevent  the  escape  of  the  insects. 

We  have  even  made  use  in  our  laboratory  of  pasteboard  shoe-boxes 
with  the  middle  part  of  the  cover  cut  out  (leaving  but  an  inch  or  so  around 
the  edges),  and  mosquito  netting  pasted 
over  the  hole.  Into  such  a  box  fresh 
leaves  must  be  put  often,  but  beyond 
the  trouble  it  serves  very  well.  Specially 
made  rearing-cages  (Fig.  807)  of  various 
kinds  can  be  bought  of  dealers  in  natural- 
ist's supplies,  but  they  are  mostly  rather 
expensive. 

For  larvae  that  live  underground 
cages  with  soil  in  must  be  provided. 
The  principal  difficulty  of  rearing  such 
insects  is  to  keep  the  right  degree  of 
moisture  in  the  soil.     If  too  damp,  fungi 

grow  and  envelop  the  insects;  if  too  dry,  the  larvae  soon  die.  For  the  study 
of  insects  that  live  on  the  roots  of  live  plants  Comstock  has  devised  a  special 
form  of  breeding-cage  known  as  the  root-cage.  "In  its  simplest  form  this 
cage  consists  of  a  frame  holding  two  plates  of  glass  in  a  vertical  position 


Fig.    811.— Soap-box   breeding  -  cage. 
(After  Comstock.) 


644  Collecting  and  Rearing  Insects 

and  only  a  short  distance  apart.  The  space  between  the  plates  of  glass, 
is  filled  with  soil  in  which  seeds  are  planted  or  small  plants  set.  The  width 
of  the  space  between  the  plates  of  glass  depends  on  the  width  of  two  strips 
of  wood  placed  between  them,  one  at  each  end,  and  should  be  only  wide 
enough  to  allow  the  insects  under  observation  to  move  freely  through  the 
soil.  If  it  is  too  wide,  the  insects  will  be  able  to  conceal  themselves.  Im- 
mediately outside  of  each  glass  there  is  a  piece  of  blackened  zinc  which  slips 
into  grooves  in  the  ends  of  the  cage,  and  which  can  be  easily  removed  when 
it  is  desired  to  observe  the  insects  in  the  soil." 

Many  caterpillars  and  other  larvae  which  live  above  ground  in  the  larval 
stage  when  ready  to  pupate  crawl  down  to  the  ground  and  burrow  into  it. 
For  these  soil  must  be  provided  in  the  rearing-cages,  or  the  larvai  when 
ready  to  pupate  must  be  removed  from  the  meat-safe  and  bell-jar  cages 
to  boxes  containing  soil.  This  soil  must  not  be  allowed  to  dry  out  entirely, 
nor  yet  must  it  be  too  moist.  Experience  is  the  only  teacher  that  will  deter- 
mine for  the  novice  the  "just  right"  condition. 

It  may  be  necessary  to  keep  pupae,  in  cocoons  or  in  underground  cells,  o\-er 
winter,  for  many  insects,  especially  in  the  eastern  and  northern  states,  pass 
the  winter  in  the  pupal  stage.  "  Hibernating  pupae  may  be  left  in  the  breed- 
ing-cages or  removed  and  packed  in  moss  in  small  boxes.  Great  care  should 
be  taken  to  keep  moist  the  soil  in  the  breeding-cages,  or  the  moss  if  that 
be  used.  The  cages  or  boxes  containing  the  pupae  should  be  stored  in  a 
cool  cellar,  or  in  an  unheated  room,  or  in  a  large  box  placed  out  of  doors 
where  the  sun  cannot  strike  it.  Low  temperature  is  not  so  much  to  be  feared 
as  great  and  frequent  changes  of  temperature.  Hibernating  pupae  can 
be  kept  in  a  warm  room  if  care  be  taken  to  keep  them  moist,  but  under  such 
treatment  the  mature  insects  are  apt  to  emerge  in  midwinter."  Eggs  of 
insects,  laid  in  the  fall,  may  also  be  kept  over  winter,  but  one  must  be  careful 
to  preserve  them  in  a  cold  place — as  an  unheated  attic  or  cellar. 

Directions  for  making  and  maintaining  observation  beehives  and 
formicaries  (artificial  ant's  nests)  are  given  on  pp.  532  et  seq.  and  pp.  54S 
et  seq.  of  this  book. 

Aquarium. — Many  accounts  of  how  to  make  and  keep  up  aquaria  have 
been  published.  The  following  directions  have  been  written  by  Miss  Isabel 
McCracken,  an  assistant  in  my  laboratory,  who  has  made  and  successfully 
maintained  many  small  aquaria  in  schools: 

To  make  the  aquarium  get  a  board  17X13X1^^  inches  thick,  grooved  all 
around  about  i  inch  from  the  edge  with  a  half-inch  groove,  and  painted 
white.  This  is  for  the  base.  Get,  two  pieces  of  double-thick  glass  15X9 
inches  for  sides  and  two  pieces  11  X9  inches  for  ends.  Set  the  glass  into 
the  grooves  of  the  wooden  base,  bind  the  corners  where  the  edges  of  the 
glass  come  together  with  strips  of  coarse  muslin  or  cambric  glued  on  the 


Collecting  and  Rearing  Insects 


645 


outside.     (Bicycle-tape  is  good.)     Place  an  oblong  strip  of  glass  8^X1  inch 
across  the  inside  of  each  corner.     Fill  the  space,  thus  formed,  with  cement. 


Fig.  812. — Battery-jar  aquarium.     (After  Jenkins  and  Kellogg.) 

Fill  in  the  grooves  of  the  bottom  board  with  cement  before  pressing  down 
the  panes  of  glass.  Where  the  glass  sides  join  the  bottom  board  use  cement 
carefully  both  inside  and  out,  filling  all  the  cracks. 

The  cement  should  be  made  according  to  the  following  formula: 

White  sand i  part. 

Plaster  of  Paris i      " 

Litharge i      " 

Powdered  resin ^    " 

Make  into  a  stiff  paste  with  boiled  linseed-oil.  Use  as  little  oil  as  possible 
and  take  proper  care  in  mixing.  Leave  for  several  days  to  harden  the 
cement.     Then  fill  slowly  and  pour  off  the  water  several  times  before  using. 

Place  an  inch  and  a  half  of  sand  on  the  bottom  of  the  box.  This  sand 
should  be  previously  baked  or  boiled  to  rid  it  of  bacteria.  Its  main  purpose 
is  as  an  anchorage  for  growing  plants.  Over  this  place  a  layer  of  variously 
sized  pebbles  treated  in  the  same  way.  These  form  hiding-places  for  the 
aquatic  fauna.  Fill  with  water  to  the  depth  of  five  or  six  inches.  Stock 
with  water-plants,  the  streams  or  ponds  of  the  neighborhood  to  determine 
the  kind.  Watercress,  water-crowfoot,  Potamogeton,  Chara,  and  eel- 
grass  are  good  kinds.     Parrot's-feather  can  usually  be  obtained  at  nurseries. 


646  Collecting  and  Rearing  Insects 

Tradescantia  (wandering-jew  or  inch-plant)  is  also  useful.  Avoid  the 
use  of  algae  (pond-scum).  The  function  of  the  plants  is  chiefly  to  oxygenate 
the  water.  The  roots  of  cress  will  furnish  food  for  some  vegetable-feeding 
animals. 

An  aquarium,  to  be  in  good  condition,  must  be  kept  aerated,  must  be 
kept  clean,  and  its  temperature  mvist  not  be  suddenly  changed.  Sufficient 
air  is  sometimes  maintained  by  plant-life  alone.  Unless  this  proves  to  be  so, 
shown  by  the  healthy  condition  of  both  plants  and  animals,  dip  up  a  few 
cups  of  water  everyday  and  let  it  fall  back  into  the  aquarium.  All  uneaten 
food,  dead  animals,  or  decaying  leaves  must  be  removed  at  once.  An 
apparatus  for  removing  such  is  described  in  a  later  paragraph. 

The  aquarium  should  be  in  the  light  to  enable  the  plants  to  produce 
oxygen,  but  not  in  direct  sunlight.  If  it  stands  in  a  sunny  window,  it  should 
be  screened  from  the  sun.  Water  lost  by  evaporation  must  be  replaced, 
but  the  fresh  water  must  not  differ  materially  in  temperature  from  that  in 
the  aquarium.  If  a  film  appears  on  the  surface  of  the  water,  it  is  due  to 
bacteria  and  dust.  It  prevents  absorption  of  air  at  the  surface  of  the  water. 
It  may  be  removed  by  absorbent  paper  (newspaper  or  blotting-paper).  It 
may  be  prevented  by  thorough  cleanliness  and  by  using  a  coarse  cheese- 
cloth cover  when  not  under  observation.  Never  give  more  food  than  is 
eaten. 

Implements  for  use  in  connection  with  the  aquarium  are  the  following: 
A  small  dip-net  made  by  twisting  a  wire  about  a  bottle  for  the  ring  and  the 
ends  about  each  other  for  a  handle, — the  net  to  be  made  of  coarse  cheese- 
cloth or  bobinet,  used  for  removing  certain  objects ;  a  piece  of  flannel  wrapped 
about  a  stick  for  cleaning  the  sides  of  algae,  which  are  bound  to  accumulate. 
For  removing  small  particles  from  the  bottom,  a  ^-inch  glass  tube  long 
enough  to  reach  to  the  bottom  is  useful.  Close  the  upper  end  with  the  finger, 
hold  the  other  end  over  the  object  to  be  removed,  Hft  the  finger,  and  the 
water  will  rush  up  the  tube,  carrying  out  the  object.  Replace  the  finger  on 
the  upper  end  and  Hft  the  tube  out  of  the  water.  For  removing  a  quantity 
of  sediment,  a  long  narrow  chimney  tightly  fitted  at  each  end  with  a  cork 
is  required.  Insert  through  the  center  of  the  corks  a  short  piece  of  glass 
tubing,  and  use  as  described  for  the  simple  glass  tube. 

To  stock  the  aquarium  choose  animals  that  are  adapted  to  life  in  still 
water,  and  keep  cannibals  by  themselves.  A  wire  netting  will  keep  in  flying 
insects. 

Of  the  insects  that  may  be  kept  in  an  aquarium  some  spend  their  entire 
life  in  the  water,  while  others  are  aquatic  during  one  stage  of  existence  only. 
Among  the  insects  easily  kept  in  aquaria  are  the  predaceous  diving-beetles, 
the  young  of  which  are  known  as  water-tigers  and  feed  on  small  earthworms 
and  other  insects,  as  mosquito-wrigglers,  May-fly  nymphs,  etc.;   the  water- 


Collecting  and  Rearing  Insects  647 

scavenger  beetles;  back-swimmers;   water-boatmen;   dragon-fly  and  May-fly 
nymphs;  mosquito  larvae,  etc. 

Other  animals  may  of  course  be  kept  in  the  aquarimn.  Common  pond- 
snails  will  live  easily,  feeding  on  green  slime,  roots  of  water-plants,  bits  of 
cabbage,  etc.;  minnows  will  eat  bits  of  fresh  meat,  and  also  the  insects; 
quarrelsome  little  sticklebacks  will  eat  the  pond-snail  eggs  and  small  crusta- 
ceans, as  Cyclops,  etc. ;  frog  and  salamander  larvae  feed  at  first  on  vegetable 
matter,  later  on  bits  of  meat,  tiny  earthworms,  mosquito  larvae,  etc. 

Remember  that  an  aquarium  needs  daily  care  to  keep  it  in  good  condition 
The  foregoing  account  of  collecting,  preserving,  and  rearing  insects  has 
been  made  short  and  only  a  general  course  of  procedure  indicated,  with  the 
hope  in  mind  of  avoiding  the  confusion  to  the  beginner  likely  to  result  from 
a  longer  account,  including  many  "specialties"  and  refinements  in  collect- 
ing methods.  Numerous  excellent  extended  directions  for  collecting,  pre- 
serving, and  rearing  have  been  published.  Two  such  accounts  are  those 
by  Comstock  in  "Insect  Life"  (Appletons),  pp.  284-335,  ^^^  by  Packard  in 
"Entomology  for  Beginners"  (Holt  &  Co.),  pp-  224-288. 


INDEX 


Illustrations  are  indicated  by  an  asterisk.  Page  references  in  black  face 
type  are  to  definitions  of  technical  terms.  Etymologies  are  given  for  the 
order,  suborder,  superfamily,  and  family  names.  In  etymologies  of  names 
derived  from  the  Greek,  the  Greek  is  followed  by  the  transliteration  (in 
italics)  of  the  Greek  letters  into  Latin  letters,  and  that  by  the  English 
meaning;  in  those  derived  from  the  Latin,  the  Latin  (in  italics)  and  the  Eng- 
lish meaning  are  given;  in  those  derived  from  other  languages,  the  nativity 
of  each  word  is  specifically  indicated.  Each  of  the  family  names  has  been 
derived  by  adding  -idee  (having  the  force  of  a  patronymic)  to  the  name  of 
the  type-genus,  which,  in  the  index,  immediately  follows  the  family  name. 
The  family  termination  is  not  repeated  throughout  the  etymologies  and 
should  be  supplied  by  the  reader. 


Abbott-sphinx,     larva     of, 
*437;  tufted-bodied,  437 
Abdomen,  parts  of,  7 
Acalyptrate  Muscidse,  341 
Acanthaclisis,  232 
Acanthia  Jiirundinis,  206 
Acanthiidas,       A  c  a  n  t  h  a 
(aKavOa,  acantha,  thom) , 
195.  205 
Achemon       sphinx -moth, 

larva  of,  *43i 
Achorntcs  nivicola,  *64 
AcliunDii  brevipcnne,  142 
Acoloithns  falsarius,  387 
Acridiidse,       A  c  r  i  d  i  u  m 
{aKpi6iov,acridium,  dim.  of 
a/cp/f,    locust),    126,    133; 
auditory  organ  of,  *I34, 
135-,  impaled  by  shrike, 
*I34;      life-history      of, 
136;  key  to  subfamilies 
of,   136;   migratory  spe- 
cies of,   133 ;  sounds  of, 

Acridiinse,  136. 

Acronycta  americana,  404; 

impressa,  *405 ;  occiden- 

talis,  *404 ;   occidentalis, 

larvae  of,  *404 
Adalia  bipunctata.  287 
Adephaga      {uSriv,        aden, 

enough ;    (payelv,  phagen, 

eat),  251 
Admiral,  red,  454 
^cilius  sulcatus,  stages  in 

development  of  nervous 

system  of,  *25 
Mschna    constricta,    head 

of,  *93 


yEschnidse,  ^schna  (prob. 
alaxpog,  aischrus,  ugly), 
91,92 

Agamic,  173 

Agaristidae,  Agarista 
(etym.  uncertain),  407 

Agenius,  499 

Aglais  milberti,  456 

Agonoderus  pallipes,  255 

Agrilus,  266 ;  ruficollis, 
267 

Agrionidae,  Agrion  ( aypiog, 
agrius,  wild),  89,90 

Agrotis  ypsilon,  402;  vena- 
tion of,  *404 

Ailanthus-worm  moth,  421 

Air-bush  bug,  205 

Akidoproctus,  118 

Alaus  oculatus,  *268 

Alder-blight,   180. 

Aletia  argillacea,  404 

Aleyrodes,  respiratory  sys- 
tem of,  *I9 

Aleyrodes  iridescens,  *I92 ; 
nierlini,  enlarged  details 
of  pupa,  *I93  ;  pupa-case 
of,  *I93;  pruinosa,  *I92; 
tcntacu  latus,  *ig2 

Aleyrodidae,  Aleurodes 
(aXevp(j67jg,  aleurodes, 
floury),  166,  190 

Alimentary  canal.   13 

Alimentary  canal  of  cock- 
roach, *I4;  of  dobson- 
fly,  *i6;  of  harlequin- 
fly,  *I5 ;  of  locust,  *I4; 
of  thrips,  *I5 

Allantus  basillaris,  *4,64 

Allorhina  nitida,  276 


Alternation  of  generations 

of  gall-flies,  469 
Alulet,  327 

Alypia  8-maculata,  *4o8 
Amber-wing       dragon-fly, 

*95 
Amblychilia         cylindri- 

formis,  253 
Amblycera     ( afi3}.vq,     am- 

blys,  blunt ;    Kepag,  ceras, 

horn),  key  to  genera  of, 

118 
Amblycorpha  oblongifolia, 

*i5i ;  rotundifolia,  151 
Ambrosia-beetle,  299 
Ambush-bugs,  195 
American  blight,  179 
American      locust,      *I39, 

141  _ 
American       tortoise-shell, 

455 
Ammophila,    nest-building 

of,  *494;  nest-burrow  of, 

*494 ;  nesting-ground  of, 

*492;  nesting  habits  of, 

492 ;    putting    inchworm 

into  nest-burrow,  *493 
Amnion,  38 
Ampelophaga  myron,  434, 

435  ;  zrr.ytVo/or,  435 
Amphibolips  coccinea;, 

471  ;  spongiiica.  471 
Aniphiccrns  bicaudatus, 271 
Amphientomum,   112 
Amphigerontia,  113 
Amphion  nessus,  *438 
Anal  veins  (see  venation) 
A  n  a  b  r  u  s  purpurascens, 

*i56,  157 


650 


Index 


Ancea  andria,  455 
Anaphothrips  striatus,  221 
Anarsia  lineatclla,  2>7A 
Anasa  tristis,  *2i3 
Anatis  15-punctata,  287 
Anatomy,   internal,   13;   of 
larva  of  giant  crane-fly, 
*2i ;  of  monarch  butter- 
fly, *I3 ;  of  silkworm,  430 
Anax  jttnitis,  head  of,  *93  ; 
stages  in  development  of, 
*83 
Ancistrona,   119;  gig  as, 

*i2i,  122 
Ancyloxypha  numitor,  443 
Andrena,    517;    nest    of, 

*5i6 
Andrenidse,       Andrena 
{avSprjvT),    andrene,  bee), 

Andriciis  calif  amicus,  472 ; 

gall  of,  *473 
Androconia  from  wings  of 

butterflies,  *592,  445 
Angerona   crocotaria,   398, 

*399 
Angle-wings,  452 
Angoumois        grain-moth, 

375 

Angular-winged  katydid, 
*i5i 

Anisolahis  annulipcs,   162 

Anisomorpha,   133 

Anisoptera  {aviaog,  anisus, 
unequal ;  Trrepoi',  ptcrurn, 
wing),  89;  key  to  fami- 
lies of,  91 

Anisopteryx    pomctaria, 

397 

Anisota  ruhicunda,  427; 
senatoria,  *428,  429; 
stigma,  428 ;  virginiensis, 
428 

Anobium,  113,  271 

Anoniiopsyllus  nudatus, 
356 

Anopheles,  305,  307;  ma- 
culipcnnis,  *3o8;  sp., 
eggs  of,  *3o6 

Anosia  plcxippus,  *45i ; 
arrangement  of  pharynx, 
cesophagus,  etc.,  in  head 
of,  *36i  ;  complete  meta- 
morphosis of,  *44 ;  cross- 
section  of  sucking  pro- 
boscis of,  *36i  ;  devel- 
opment of  color-pattern 
in  pupal  wings  of,  *596 ; 


development  of  scales  of 
wing  of,  *59S ;  external 
parts  of,  *6;  internal 
anatomy  of,  *I3 ;  larva 
of,  *6os ;  mimicry  of,  by 
viceroy  butterfly,  *6io; 
part  of  maxillary  pro- 
boscis of,  showing  ar- 
rangement of  muscles, 
*36i ;  part  of  wing  of, 
showing  scales,  *36o ; 
venation  of,  *ii;  vena- 
tion of  wings  of,  *37i 

Ant,  California  black, 
*535  ;  driver,  543  ;  honey, 
545;  little  black,  *536; 
red,  541 ;  slave,  547 ; 
slave-maker,  547 ;  velvet, 
497 ;  Western  agricultu- 
ral, mound-nest  of,  *542 

Antelope-beetle,  273 

Antenna,  *3 ;  of  carrion- 
beetle  showing  olfactory 
pits,  *2y ;  of  beetles,  *2So 

Ant-guests,  *553 

Anthidium,   514 

Anthomyiinse,   341.   345 

Anthonomus  grandis,  296; 
quadrigibhtis,  296 ;  sig- 
natus,  296 

Anthophora,  515;  pilipes, 
mouth-parts  of,  *5i2 ; 
stanfordiana,   516 

Anthophoridas,  Anthophora 
(^av6o(p6pog,  anthophorus, 
flower  bearing),  515    . 

Anthrax,  334 ;  fiilviana, 
venation     of     wing     of, 

""32,2, 

Anthrenus  museorum,  263 ; 
scrophularice,  *26s,  264; 
varius,  263 

Ant-lions,  55,  30 

Ants,  56,  _  463,  533 ;  and 
rose-aphids,  *I74;  arti- 
ficial nests  for,  548 ;  com- 
munal life  of,  537;  dia- 
grams of  lateral  aspect 
of  abdomen,  *540 ;  in- 
stincts of,  554 ;  key  to 
families  of,  540 ;  relation 
to  aphids,   175 

Apanrcsis  virgo,  413 

Aphidiidas,  Aphis  ( cKbEiSeT?, 
aphides,  lavish),  166, 
171 

Aphids,  171 ;  as  ants'  cat- 
tle,   175 ;  honey-dew  of, 


175,   180;  killed  by  Hy- 

menopterous      parasites, 

*I73 ;  wax  of,  175 
Aphis-lion,  228,  229,  230 
Aphis  mali,  174 
Aphodius   Hmctarius,    274; 

oblongus,      275 ;      tcrmi- 

nalis,  275 
Aphoruridae,     Aphrophora 

{u(l>po(p6po(; ,    aphrophorus, 

foam-bearing),  63 
Aphrophora  4-notata,  171 ; 

signoreti,  171 
Apidae,      Apis  {apis,  bee), 

Apina,  (see  Apidae),  463 
Apis  Horca,  comb  of,  *520; 
mellHica,  520,  521  ;  inclli- 
Hca,    hind   leg   of,    *52i ; 
mellifica,  stages  in  devel- 
opment of  nervous   sys- 
tem   of,    *24 ;    mclliiica, 
varieties  of,  *S2i 
Apoidea  (see  Apidse),  511 
Apple  aphids,  174,  179 
Apple     bucculatrix-moths, 
376 ;    pupal    cocoons    of, 

*375.  *37^ 
Apple     tent-caterpillars, 

*359 
Apple-tree   borer,    *266, 

*285 
Aphodius,  274 
Aptera      (a,     a,    without; 

nTepov,pterum,  wing).  52, 

58 ;  ovarial  tubes  of,  *59 ; 

respiratory     system     of, 

*59 
Aquarium,      battery-jar, 

*645 ;     for     dragon-fly 

nymphs,     *88 ;     how     to 

make     and    maintain, 

644 
Aquatic  muscid,  *348,  *350 
Arachnida,  3 
Arachnis  picta,  413 
Aradidoe,    Aradus  {apa<)oq, 

aradus,   rumbling),    195, 

207,  208 
Aradus  cinnamomeiis,  208. 

*209 

Aramigcs  fiillcri,  295 
Arctiidse,      Arctia  (arktos, 

bear),  370,  411 
Areoles,  232 
Argia  putrida,  84 
Argynnis  cybele,  456 
Arista    (antcnnal   bristle) 


Index 


651 


Aristolochia         clematitis, 

flower  of,  *575 
Aristolochia,  specialization 

of,  for  insect  pollination, 

575 
Army-worms,     325,     *403, 

404 ;   ichieumon  parasite 

of,  *482 
A  rp  1 1  ia     su  Iphurca,     *  1 44 ; 

tcncbrosa,  *I44 
Arthasia  gallcata,  *i6g 
Arthropoda,  classes  of,  2 ; 

defined,   2 
Arums,    specialization    of, 

for     insect     pollination, 

575 
Ascalaphinse,   232 ;   key   to 

genera  of,  233 
Asclepias,     catching     cab- 
bage-butterfly, *574 ;  cor- 
tinti,     specialization     of, 
for    insect    pollination, 
573  ;  incarnata,  visited  by 
insects,  571 ;  vcrticillata, 
visited    by    insects,    569, 
571 ;    visited    by    honey- 
bee, *574 
Ash-tree  borer,  *392 
Asilidge,      Asilus  {asiliis,  a 
gad-fly,  a  horse-fly),  330 
Asparagus-beetle,  278 
Aspidiotiphagus      citrinus, 

*479 

Aspidiotns  aurantii,  188, 
*i89,  *i9o;  Hens.  188; 
pcniiciosus,  *i8i,  *i82, 
*i84 

Assassin-bugs,  195,  203; 
incomplete  metamorpho- 
sis of,  *43 

Astata,  499;  unicolor,  nest- 
burrow  of,  *500 

Aster  paniculatus,  visited 
by  insects,  571 

Ateuclms  sacer,  274 

Aflious  scapularis,  268 

Atlanticus  dorsalis,  156; 
pacJiynicnis,  *I55 

Atropidje,  AtroposCArpOTrof, 
a  t  r  n  p  u  s  ,  one  of  the 
Fates),  112;  key  to  gen- 
era of,  113 

Atro^os  divinatoria,  113; 
sp.,  *II2 

Attagcnus  piceiis,  *263, 
264 

Auditory  organ  in  antenna 
of     mosqtiito,     *29 ;     of 


Acridiidae,  *i34,  135;  of 
locust,  *28 ;  of  Locus- 
tidae,  150 

Australian  lady-bird  bee- 
tle, 186,  *i87 

Autoiiicris  io,  424,  ^425 ; 
larva  of,  426;  pamina, 
424;  zelleri,  424;  zephy- 
ria,  424 

Bacillus,  132 

Back-swimmers,   194,   198 

Bacunculus,   133 

Bag-worm,  369,  *388 ; 
moth,  386,  *387;  moth, 
venation  of  wing  of, 
*389 

Balancers,  302 

Balanintis  caryatrypes , 
*295,  296;  nasicus,  296; 
qiicrcus,  296 ;  restus,  296 

Baltimore  butterfly,  456 

Banded  footman,  410  ;  pur- 
ple, 452 

Bark-lice,   11 1 

Barren-ground  locust,  *I46 

Basilarchia  archippus,  452 ; 
artheiuis,  452 ;  astyanax, 
452 ;  astyanax,  venation 
of,  *440 ;  Horidensis,  452  ; 
lorqiiini,  452 

Basilona  iinpcrialis,  426 

Battery- jar  aquarium,  *645 

Bat-tick,  351,  *352 

Beak  of  mosquito,  *302 

Bean-weevil,  277,   *28i 

Bedbugs,  195,  205,  *2o6 ; 
hunter,  masked,  203 

Bee-flies,  222,  232, 

Bee-fly,  *334 ;  mouth-parts 
of,  *334 

Beehive,  observation,  *53i, 
*532 

Bee-lice.  351 

Bee-louse,  *3S2,  353 

Bee-moth,  379 

Bees,  56,  463,  510;  carpen- 
ter, 513  ;  gregarious,  516  ; 
long-tongued,  511;  ma- 
son, 514;  mining,  513; 
mining,  nest-burrows  of, 
*5i6;  potter,  514;  short- 
tongued,  511 ;  social, 
517;  solitary,  513 

Beetles,  55,  246;  antennae 
of,  *250 ;  development 
of,  250 ;  eyes  and  tarsi 
of,   *25o;   mode  of  pin- 


ning, "^627",  tracheal  sys- 
tem of,  *i8 

Bell-jar  formicary,  *55o; 
live-cage,   *642 

Bclostouia  amcricana,  *2oo 

Belostomatidse,  Belostoma 
{piXog,  bcltis,  dart ;  aro/Mi, 
stoma,  mouth),  194,  200 

Bembccia  marginata,  391 

Bembecidae,  Bembex(/-^f/^/i/^, 
bembix,  buzzing  insect), 
500 

Beiiibex  spinoloe,  500 

Bcnactis  griscus,  200 

Berytidse,  Berytus  (Bery- 
tus,  a  seaport  town  of 
Phoenicia),   195,  214 

Bibio  albipcnnis,  *326;  ve- 
nation of  wing  of,   '^'326 

Bibio  fcmorata,  326 ;  fra- 
ternns,  326 ;  tristis,  326 

Bibiocephala  comstocki, 
heads  of  male  and  fe- 
male of,  *3i6;  larva  of, 
*3i5;  pupa  of,  *3i5;  ve- 
nation of  wing  of,  *3I7; 
doanci,  head  of  larva  of, 
showing  formation  of 
adult  head-parts,  *3i8 ; 
doanci,  mouth-parts  of, 
*9,  *3i6;  doanci,  mouth- 
parts  of  larva  of,  *3i7; 
clegantiiliis,  female,  *3i6 

Bibionidae,  Bibio  {bibis, 
an  insect,  from  bibo, 
drink),  304,  325 

Bilateral  symmetry  (halves 
of  body  similar) 

Bill-bugs,  294 

Bird-lice,  55,  113;  biting, 
III ;   remedies  for,    114 

Bird-ticks,  351 

Biston  ypsilon,   *3,g8 

Bittacus,  236 ;  ap terns,  238 ; 
strigosus,  *237 

Black  beetle,  *I28 

Black-bordered  orange, 
446 

Black-flies,  313 

Black-fly,  *3i2;  female, 
mouth-parts  of,  *3i3; 
head  of  larva  of,  show- 
ing developing  mouth- 
parts  of,  *3i4:  mouth- 
parts  of  larva  of,  *3i3; 
venation     of     wing     of, 

*3I2 

Black  scale,  187 


652 


Index 


Black  swallowtail,  450 
Blastoderm,  ^38 
Blastophaga       grossorum, 

*487 
Blattidae,     Blatta     (blatta, 

insect  that  shuns  light), 

126 
Blepharocera  capitata, 

cross-section  of  eyes  of, 

*3I7 
Blepharoceridse,  Blepharo- 
cerus  (probably  jil-f^apov, 
blepharus,     eye ;      Ktpaq, 
ceras,      divided),      304, 

314- 
Blissus    leucopterus,    211, 

*2I2 

Blister-beetle,  288 
Blood, 17 
Blow-flies,  343 
Blow-fly,    *344 ;    complete 

metamorphosis   of,   *45 ; 

compound   eye   of,   *3S ; 

larva,    pupa,    and    adult 

of,   *302 
Bluebottles,    343 
Blue-striped  looper,  ^398 
Body-louse,    *2i6 
Body-wall,  section  of,  *4 
Bolcototherus        bifurcus, 

289 ;  larva  of,  *289 
Boll-worm,  cotton,  404 
Bombidge,  Bombus  (fi6fi(iog, 

b  0  m  b  II  s  ,     a     buzzing 
•  noise),  518 
Bombus,  518;  aMnis,  519; 

calif  ornicus,     519;      sd- 

wardsii,   519;    ferviotus, 

519;   sp.,  nest  of,  *5i9; 

sp.,    worker   and   queen, 

*5i8;  tcrricola,  519 
Bombycidse,        B  o  m  b  y  x 

(bomby.v,  silk),  369 
Bombyliidse,       Bombyllius 

(fSofJtivhuc,       bombylius, 

humble-bee),  332,  2,33 
Bombylius,     2>32)  \     major, 

*334 ;    sp.,    mouth-parts 

of,  *334 
Bombyx  mori,  429;  larvae 

of.  428 ;  venation  of,  *420 
Book-lice,  55 ;  iii 
Book-louse,  *ii2 
Book-worm,   271 
Borcus  brumalis,  236;  cali- 

f  ornicus,  236  ;   nivoriun- 

dus,  236 ;  unicolor,  236 
Bot-flies,  232,  337 


Bot-fly,  larva  of,  *337;  of 
horse,  *338 

Box-elder  bug,  *2i3 

Brachycera  {Ppaxvq,  bra- 
cliys,  short;  i^epag,  ceras, 
horn),  303,  327;  division 
into  groups,  327 ;  keys 
to  families  of,  327,  332 

Brachynemurus,  232 

Braconidse,  Bracon  (Fa- 
bricius,  etym.  uncertain), 

463 

Brain  of  locust,  *22 

Braula  cceca,  353 ;  sp.,  *352 

Braulidse,  Braula  {jipavla, 
braula,  louse),  351,  353 

Breathing  of  aquatic  in- 
sects,  20 

Breeding-cage,  *64i ;  lamp- 
chimney,  *642 ;  s  o  a  p  - 
box,    *643 

Breeding-cages  how  to 
make,   642 

Broad-winged  katydid, 
*I50,   *i5i 

Brood-comb  of  honey-bee, 
with  young  stages,  *46 

Bruchidse,  Bruchus 
{ppovxog,  bruchus,  a  lo- 
cust without  wings), 
277,   281 

Bruchus  obtectus,  *28i ; 
pisi,  *28i 

Brush-footed  butterflies, 
450 

Bucculatrix  pomifoliclla, 
*376;  pupal  cocoons  of, 

*375 

Buckeye  butterfly,  455 

Bud-moth,  381 

Buffalo-gnats,   304,  313 

Buffalo-moth,   *263 

Buffalo  tree-hopper,  169 

Bug,  pinning  a,  *637 

Bugs,  55,  163 

Buprestidae,  Buprestis 
{povg,  bos,  ox;  'Kpijdeiv, 
prethen,  swell),  265,  266 

Buprestis,   267 

Burrower-bugs,  195,  215 

Burying-beetle,  *26i 

Bumblebee,  at  clover-blos- 
som, *5i8;  guest,  519; 
nest  of,  *5I9 

Bumblebee-like  robber-fly, 
*33i 

Bumblebees,  517 

Butterflies,   358,   439;   key 


to     families     of,     441 ; 
scales  of,  their  structure 
and  arrangement,  589 
Butterfly,  part  of  wing  of, 
*590 

Cabbage-bug,  harlequin, 
214,    *2I5 

Cabbage-butterfly,  caught 
by  Asclepias,  *S74;  Eu- 
ropean, 445 ;  northern, 
445 ;  southern,  445 

Cabbage  maggot-fly,  345 

C  a  c  oe  c  i  a  cerasivorana, 
*3%0',   venation  of,   *38o 

Caccccia  parallcla,  *38o ; 
pcrvadana,  380 ;  rosa- 
ceana,  380;  obsoletana, 
larva  of,  *364;  obsole- 
tana, pupa  and  adults  of, 

*365 

Csecilius,   113 

Caddis-flies,  23,  55,  240; 
keys  to  families  of,  244 

Caddis-worms,  case-build- 
ing of,  240 ;  fishing-net 
of,  *243 ;  halDits  of,  241 ; 
pupation  of,  242 ;  cases 
of,  *24i ;  key  to  families 
of,  244 

Ccenonympha     calif  ornica, 

457 

Calandra  granaria,  297; 
oryccc,  297 

Calandridae,  Calandra  (F. 
calandre,  weevil),  294, 
297 

Calephilis  cccnius,  /[^i^A, 

California  flower-beetle, 
279,  *28o ;  parasitic  fun- 
gus of,  *346 ;  tachinid 
parasite  of,  *346 

California  honey-ant,  un- 
derground nest  of,  *546 

California  oak-worm  moth, 
*4o6 

California  ringlet,  457 

California  shield-backed 
grasshopper,  *r55 

Caligo  sp.,  *6i2 

Callimorphas,  414 

Calliphora  erythrocephala, 
344 ;  complete  metamor- 
phosis of,  *45 ;  com- 
pound eye  of,  *33  ;  larva, 
pupa,  and  adult  of,  *302 

Callosamia  angulifera,  co- 
coons  of,   *423 ;  prome- 


Index 


653 


thea,  422,  *424;  cocoons 
of,  *423 ;  development  of 
color-pattern  in  pupal 
wings  of,  *597 
Calocalpe  undulata,  *299 
Calopterygidae,  Calopteryx 
(KaAof,  caliis,  beautiful ; 
nripv^,     pteryx,     flight), 

89 

Calopteryx,  89;  maculata, 
89,  *90 

Calosoma  calidum,  *254 ; 
frigidum,  *254  ;  larva  of, 
*253 ;   scrutator,  254 

Calotermes,  102 ;  casta- 
neus,  104 

Calyptrate  Muscidae,  key 
to  subfamilies  of,  341 

Camel-crickets,   155 

Camniila  pellucida,  133, 
*I45 

Campodca  sp.,  *6i ;  staphy- 
liniis,  60 

Campodeidse,  Campodea 
(KdfiKTi,  campe,  caterpil- 
lar; eU^oc,  cidiis,  form), 
60 

Camponotidse,  Camponotus 
(KafiTTT),  campc,  curve; 
vij-oc,    notus,  back),  540, 

545 
Camponotus     pcnnsylvani- 

cus,  545 
Canker-moths,      lime-tree, 

*397 

Canker-worms,  *395,  397 

Canthon,  274 

Capitate,   *250 

Capnia,  7;i ;  pygmaa,  74 

Caprification,  488 ;  figures 
showing  effect  of  non- 
caprification  and,  *489 

Capsidae,  Capsus  (prob. 
KanTEiv,  cap  ten,  gulp 
down),    195,    207,    209 

C  a  r  a  b  i  d  se,  Carabus 

(Kdpafioc,  carabus, 
horned  beetle),   252 

Carneadcs  scandens,  402 

Carolina  locust,  *i4i,   143 

Carpenter-bees,  513 ;  nest- 
tunnel  of,  *5i3 

Carpenter-moths,  369,  385 

Carpenter-wasps,  nest-tun- 
nels of,  *502 

Carpocapsa  pomonella, 
381 ;  larva  or  worm  of, 
*382 ;  pupse  of,  *383 


Carpocapsa  saltitans,  382, 
*383 

Carrion-beetle,  *26i ;  larva 
of,  *262 ;  smelling-pits 
on  antenna  of,   *27 

Cases,  for  insect  collec- 
tions, 637 

Cassida  bicolor,  281 

Castes,  503 

Cat-  and  dog-flea,  356 

Catcrva  catcnaria,  399 

Catocala  cpiorc,  401 ;  gry- 
nea,  *400,  401 ;  nupta, 
ommatidia  of,  *32 ;  pala- 
ogama,  *400 ;  relicta, 
401 ;   ultronia,  *400,  401 

Catopsila  eubule,  446 

Caudal   (tailward) 

Cave-crickets,   156 

Ccanothus  americanus,  vis- 
isted  by  insects,  569 

Cccidomyia  destructor,  323 

Cecidomyiidas,  Cecidomy- 
ia  (nr/Kig,  cecis,  gallnut ; 
fivla,  niyia,  fly),  304, 
322 

Cecropia-moth,  418,  *4I9 

Celery  leaf-hopper,  *I70 

Cclithemus  epomina,   *g6 

Cell  of  wing  {space  bound- 
ed  by  veins) 

Cephalic   (hcadward) 

Cephus,  grain,  European, 
467 

Cephus  pygmceus,  467 

Cerambycidse,  Cerambyx 
(Kepafil3v^,  cerambyx, 
beetle),  277,  282 

Cerasa  bubalus,  i6g 

Ceratocampidse  (prob. 
«fp«f,  ccras,  horn  ;  KafiTrij, 
campc,  a  bend),  426 

Ceratophyllus  stylosus,  356 

Ceratopogon  sp.,  mouth- 
parts  of,  *3ii 

Cerceris  dcserta,  locality 
study  of,  *S0i ;  tuber cu- 
lata,  dragging  weevil  to 
nest,  *495 

Cerci,  73 

Cercopidse,  Cercopis  {kbpkoq, 
cercus,  tail ;  ut/",  ops,  ap- 
appearance),  166,  170 

Ccrcyonis  alope,  457 ;  pc- 
gala,  457 

Cerococcus  ehrhorni,  *igi ; 
quercus,  *ig2 

Ceruchus  piceus,  273 


Cerura,  394;  sp.,  larva  of, 

*6o7 
Ceutophilus       lapidicolus, 

*i55;    maculatus,    *IS4, 

155 
Chccrocampa  tersa,  435 
Chalcedon,  457 
Chalcid  fly,  *479 
Chalcididje,  Chalcis  (;iraA/c/f, 

chalcis,  copper),  463 
Chalcidoidea     (see     Chal- 

cididse),  477 
Chalcophora    liberta,    267; 

virginiensis,  267 
Chauliodes,  224 ;  serricor- 

nis,      adult     depositing, 

*225 

Chauliognathiis     margina- 

tus,  270;  pennsylvanicus, 

270 
Checkered  beetles,  265,  270 
Cheese-skipper  fly,  ^348 
Chelymorplia  argus,  281 
Cherry  aphis,  174 
Cherry-bug,  214 
Cherry-fruit  fly,   larva   of, 

*349;  puparia  of,  *350 
Cherry-tree  leaf  -roller, 

*38o 
Chicken-flea,  355 
Chickweed  geometer,    144, 

399 

Chigoe,  355 

Chilocorus  bivulnerus,  287 

Chinch-bug,  211,  *2I2; 
family,   195 

Chionaspis  pinifolicc,  188 

Chironomidse,  Chironomus 
(xEipovofioc,  chironomus, 
one  who  moves  hands  in 
gesticulation  [symmetri- 
cal spreading  of  feet 
when  at  rest]),  304,  310 

Chironomus,  alimentary 
canal  of,  *I5;  dorsalis, 
part  of  sympathetic  ner- 
vous system  of,  *24 ; 
nervous  system  of,  *22; 
pupa  of,  *3ii ;  sp.,  *3io; 
larva  of,  *3ii 

Chitin,  4 

Chloealtis  conspersa,  *I40, 
142 

Chloroperla,  yj,,  74 

Chlorops  similis,  350 

Chorion,  37 

Chortophaga  viridifasciata, 
144,  *I45 


654 


Index 


Chrysalid,  44 

Chrysididse.  Chrysis  (.rP'^ff'f . 
chrysiSj  a  vessel  of 
gold),  463,  498 

Chrysohothris  fcmorata, 
*266 

Clirysochus  aurahis,  280; 
cobaltinus,  280 

Chrysomelidse,  C  h  r  y  s  o  - 
m  e  1  a  (jcpvaofirjTi.o'kovdLov. 
chrysomclolonthium,  lit- 
tle golden  beetle),  277, 
286 

Chrysopa  sp..  *228 

Chrysophamis  tlioc,  444 ; 
venation  of,  ^440 

Chrysophila  thoracia,  ve- 
nation of  wing  of,  *330 

Chrysopidae,  Chrysopa 
{xpvouxp,  chrysops,  gold- 
en eyes),  224,  228 

Chrysops  sp.,  venation  of 
wing  of,  *328 

Cicada,  mouth-parts  of, 
*q;  scpjtcndccim,  mouth- 
parts  of,  *9;  scptcndc- 
ciin,  166,  *i67;  tibicen, 
167;  seventeen-year,  166, 
167 

Cicida-killer,  500 

Cicadids,  Cicada  (r/carfa), 
166 ;  sound-making  or- 
gan of,  *i67 

Cicadula  exitiosa,  170 ;  4- 
lincata,  *I70 

Cicindela  hybrida,  larva 
of,    *252 

Cicindelidse,  Cicindela 
(candcia,  light),  252 

Ctcuta  macnlata,  visited 
by  insects,  571 

Cigarette-beetle,  271 

Circotettix  vcrruculatus, 
*i46 

Circulatory  system,  16;  of 
young  dragon-fly,   *I7 

Cisthene  uni fascia,  410 

Citheronia  rcgalis,  426, 
*427;  larva  of,  *366, 
*427 

Class,  2 

Classification,   52 

Clastoptera  pini,  171 ;  pro- 
teus,  171 

Clavate,  *250 

Clavicornia  (clava,  club; 
cornu,  horn),  251,  264; 
key  to  families  of,  258 


Claytonia  virginica,  visited 
by  insects,  569 

Clear-winged  moths,  368, 
388;   sphinxes,  438 

Cleridse,  Clerus  {n/S/pnc, 
clcrus,  mischievous  in- 
sect, so  named  by  Aris- 
totle), 265,   270 

Clerus  dubius,  270;  nigri- 
fons,  270;  nigripes,  270; 
sanguineus,  270 

Click-beetle.  265,  267 ; 
larva  of,  *268 ;  snapping 
apparatus  of,  *267 

Climacia,  229 

Clisiocampa  amcricana, 
415;  larva  of,  *359;  ve- 
nation of,  *4i8;  disstria, 
stages  of,  *4i7 

Close-wings,  277 

Clothes-moth,  *373,  374 ; 
case-bearing,  374 

Clothilla,  113 

Clouded   locust,    *I45,    146 

Clouded-sulphur,  446 

Cob(ra  scandcns,  visited  by 
insects,  567 

Coccidse,  Coccus  (  k6kko^, 
coccus,  berry  or  kermes 
insect),  166,  180 

Coccinella  abdominalis, 
*286 ;  californica,  *286 ; 
calif ornica,  stages  of, 
*287;  novcmnotata,  2^7; 
oculata,  *286 :  sanguinca, 
*286;   trifasciata,  *286 

Coccinellidse,  Coccinella 
(dim.  of  coccinus,  scar- 
let  garments),   282,   286 

Coccotorns  Scutellaria,  296 

Cockroach,  alimentary  ca- 
nal of,  *I4;  egg-case  of, 
*i27  ;  tracheae  in  head  of, 
*I9;  wood.  *I28 

Cockroaches,  53,  126 

Cockscomb  gall-louse,   180 

Codlin-moth,  381  ;  larva  or 
worm  of,  *382 ;  pupae  of, 
*383 

Cccnis  dimidiata,  *69 

Coleoptera  (ko^ieo^,  co- 
leus,  sheath  ;  Trrepdv, 
pterum,  wing),  55,  246; 
genuina,  251  ;  key  to  sec- 
tions and  tribes  of,  251 

Collecting  insects,  direc- 
tions for,  635 

Collecting-net,  *635 


Collembola     (koaao,     colla, 
glue ;  kjijioHi  embole,  in- 
sertion,   i.  e.,    closely 
joined,  well  framed),  60, 
62 ;    key   to   families   of, 
63 
Colletes,  513 
Colobopterus,  233 
Colopha  ulmicola,  180 
Colorado       potato  -  beetle, 

*278 
Coloration,   directive,   607 
Color-pattern,  develop- 
ment  of,  in  giant  wood- 
boring  beetle,   *598 ;   de- 
velopment   of,    in    pupal 
wings    of    monarch-but- 
terfly,     *596 ;     develop- 
ment of,  in  pupal  wings 
of  promethea-moth,  *597 
Colors,  analytical  table  of, 
of  insects,  588 ;  chemical, 
how  produced,  586 ;  hy- 
podermal,   587  ;  of  flow- 
ers,   developed    for    at- 
traction of  insects,  566 ; 
of     insects,     advantages 
of,  584 ;    of  insects,   de- 
velopment of,  596;  of  in- 
sects,   their    causes    and 
uses,  583 ;  physical,  how 
produced,  586 ;  produced 
by  scales,  594;  warning, 
604 ;  cuticular,  587 
Colpocephalum,   119 
Comma-butterfly,    *453 
Communal     life     of    ants, 
537 ;    of    the    honey-bee, 

Compsomyia       macellaria, 

344 
Compton   tortoise,   456 
Cone-nose,    blood-sucking, 

203,  *204 
Coniopterygldae,   C  o  n  i  o  - 

p  t  e  r  y  X    (  kuvic,    conis, 

dust ;  TTTepv^,   p  t  e  r  y  X  , 

wing),  224,  235 
Conocephalus,      154;      cn- 

sigcr.  *I53 
Conopidae,  Conops  (kwpwV. 

conops,  gnat),  332,  336 
Conops,  ZZ7 
Co  no  rh  in  us  sanguinisugus, 

203.    *204 

Conotraclielus      nenuphar, 

*2g6 ;  cratcrgi,  *297 
Copris  Carolina,  274 


Index 


6J5 


Coptocyla  aiirichalcca, 
*28o ;  clavata,  281 

Coral-winged  locust,  *I42, 
144 

Corbiculum,  514,  *52i 

Cordate      {heart    shaped) 

Cordulegaster,  92 

Cordulegasteridifi,  Cor- 
dulegaster (prob. 
liopilvXjj,  cordylc,  a  club ; 
yaarr/p,  gastcr,  belly), 
92 

Coreida:,  Coreus  {k^'piq, 
coris,  bedbug),   195,  207 

Corcthra  sp.,  *309;  pupa 
and  larva  of,  *309 

CorimclcEtia  publicaria,  215 

Corimelasnids,  Corimelrena 
(  Kupig,  coris,  bedbug  ; 
ue^avla,  mclaina,  f.  of 
mclas,  black),   195,  207, 

215 

Corisa  sp.,  *I99 

Coriscnm  cuculipcnncllum, 
moth  and  leaf  rolled  by 
larva  of,  *378 

Corisciis  subcoleoptratus, 
204 

Corisidse,  Corisa  (x^pic, 
coris.    bug),    194,    198 

Corn-bill  bug,  297 

Cornroot-louse,  and  shep- 
herds of,  175 

Corn-worm,   404 

Corrodentia,  (corrodere, 
gnaw  to  pieces),  55,  iii ; 
life-history  of,  in;  oe- 
sophageal sclerite  o  f , 
112;  structure  of,  in, 
112;  table  of  families  of, 
112 

Corydalis,  224 

Corydalis  cornuta,  *226; 
alimentary  canal  of,  *i6; 
development  of  mouth- 
parts  of,  *227 ;  habits  of, 
227 ;  head  of,  showing 
mouth-parts,  *6 

Corymbctcs  hamatus,  268; 
hicroglyphiciis,   268 

Corythuca,  sp.,  *2o8;  ar- 
ciiata,  208 

Cos)iiopepla   carnifex,   214 

Cosmosoma  auge,  41G 

Cossid,  venation  of  a,  *385 

Cossidse,  Cossus  {cossus, 
a  larva  under  bark  of 
trees),  369,  385 


Cossus  populi,  385 
Costa   {sec  venation) 
Costal,  460 
Cotalpa  lanigcra,  276 
Cotton-stainer,  210 
Cotton-worm,  404 
Cow-ants,   498 
Cow-killer,  *497,  498 
Coxa,  *3,  *6,  *247 
Crab-louse,   *2i7;   egg  of, 

*2I7 

Crabro  stirpicola,   502 

Crabronidse,  Crabro  {cra- 
bro, hornet),  502 

Crambidae,  C  r  a  m  b  u  s 
{Kpafi,8og,  crainbus,  dry, 
shriveled),  277 

Crainbidia  cephalica,  410; 
pallida,  410 

Cranberry  leaf-roller, 
*38o;  spittle  insect,  171; 
worm-moth,  *38i 

Crane-flies,  304,  321 

Crane-fly,  giant,  anatomy 
of  larva  of,  *2i  ;  degen- 
erating muscle  from  pu- 
pa of,  *5o;  development 
of  wing-buds  of,  *48 ; 
salivary  glands  of,  be- 
fore and  after  degenera- 
tion, *5i ;  stages  of, 
*T,^2 ;  venation  of  wing 
of,   *32I 

Creinastogastcr  lincolata, 
544;   shed-nest  of,  *543 

Crcophihis  villosiis,   *26o 

Crepidodera  cucumeris, 
281 

Crickets,  53,  126,  157; 
ant-loving,  161 ;  burrow- 
ing, 161  ;  degenerate 
forms,  162 ;  sound-mak- 
ing file  of,  *IS7 ;  wing- 
less striped,  chirping  of, 
159 

Crioceris  asparagi,  278 

Cross-pollination,  564;  of 
flowers  by  insects,  how 
developed,  581 

Croton-bug,  128,  *I28 

Crustacea,  3 

Ctcnoccphaliis  canis,  *354, 
356 

Ctenucha  multifaria,  410 ; 
ruberoscapus,  410 ;  ve- 
nosa,  411;  virginica, 
410;  venation  of,  *4il 

Cubitus  {see  venation) 


Cuckoo-flies,  463,  498 

Cucujidse,  Cucujus  (Bra- 
zilian cuciijo,  a  bu- 
prestid  beetle),  258,  262 

Cucujus  Aavipes,  263 

Cucumber-beetle,  279,  *28o 

Cucumber    flea-beetle,    281 

Culex,  305,  307 

Culcx  fatigans,  scales  on 
wings  of,  *3io;  head  of, 
*7 ;  incidcns,  eggs  of, 
306;  life-history  of-, 
*305 ;  mouth-parts  of, 
*30i 

Culicidse,  Culex  {culex. 
gnat),  304,  305 

Curculionidse,  Curculio 
{curculio,  weevil),  294, 
295 

Curculios,  294 

Cucullia,  402 

Currant-angerona,  *399 

Currant-borer,   390 

Currant  endropia,  *399 

Currant-slug,  *465 

Currant-stem  girdler,  *465 

Currant-worm,  imported, 
466 ;  native,  466 

Cuterebra  cuniculi,  338; 
larva  of,  *237 

Cuticle,  4;  chitinized,  *S 

Cutworm,  *402 ;  climbing, 
402 

Cyaniris  pseudargiolus,  443 

Cybister,  255,  257 

Cydnidse,  Cydnus  {KV(h6(, 
cydnus,  famous),  195, 
207,  216 

Cyllcnc  pictus,  284 

Cvinatopliora  pampinaria, 
"*3?8 

Cynipidse,  Cynips  ( Kviip, 
cnips,  name  of  several 
insects),  463,  467;  al- 
ternation of  generations 
of.  469 

Cynipoidse  (see  Cynipi- 
d£e),   478 

Cynips  quercus-saltatrix, 
_  *474  ;  galls  of,  *473 

Cyrtophylliis  c  oncavus , 
*i5o,  *i5i 

Dagger-moth,  gray,   *404; 

larvas  of,   *404 ;   r  a  s  p  - 

berry,  *40S 
Damsel-bug,  195,  204,  *205 
Damsel-flies,  53,  75,  *78 


656 


Index 


Damsel-fly,  nymph  of,  *84 ; 

ruby-spot,  *90 
Dance-flies,  332,  334 
Dance-fly,  mouth-parts  of, 
*335 ;  venation  of  wing 
of,  *335 
Darkling      ground-beetles, 

288 
Dasyllis  soceata,  *33i 
Datana  angusii,  394;  min- 

istra,  393 
Datura    stramonium,    spe- 
cialization of,  for  insect 
pollination,  571 
Daunus  swallowtail,  449 
Dead-leaf  butterfly,  *6oi 
Death's-head  sphinx-moth, 

*438,  *6i3 
Death-watch,  271 ;  beetles, 

265 
Deer-flies,  328 
Degeneration,        among 

scale-insects,    180,    188 
Deilephila  lineata,  435 
Dejeania  corpulenta,  *346 
Dendroctonus   valens,   299 
Dendroleon,  232 
Dermatobia     cyaniventris, 

339;  noxialis,  339 
Dermestes  lardarius,  *264 
Dermestidse,  Dermestes 
( Sspua,  derma,  skin; 
eaSietv,  esthien,  eat),  258, 
263 
Desmia  maculalis,  378 
Desmocerus  palliatus,  284 
Development,  35 ;  of  bee- 
tles, 250;  of  color-pat- 
tern in  giant  wood-bor- 
ing beetle,  *598 ;  of  color- 
pattern  in  pupal  wings  of 
monarch  butterfly,  *596 ; 
of  color-pattern  in  pupal 
wings  of  promethea 
moth,  ■  *597  ;  of  egg  of 
fish-moth,  *4o;  of  egg 
of  saw-fly,  *39;  of  egg 
of  water  scavenger-bee- 
tle, *38 ;  of  honey-bee, 
522 ;  of  malaria-produc- 
ing Haemamoeba  in  hu- 
man blood-corpuscle, 
*6i8;  post-embryonic,  of 
locust,  *42 ;  of  scales  on 
wing  of  Anosia  plexip- 
pus,  *595 ;  of  scales  on 
wing  of  Euvanessa  anti- 
opa,  *594 ;  of  wing-buds 


of  giant  crane-fly,   *48; 

of  wings  of  locust,  *42    I 
Devil's  darning-needle,  76 
Dexia,  346  : 

Dexiinse,  341,  346 
Diabrotica         12-punctata, 

279 ;     longicornis,     279 ; 

soror,  279,  *28o;  vittata, 

279 
Diapheromera       femorata, 

*i3i,  132,  *6o3 
Diaspis  rosce,  *I90 
Diastrophus     nebulosus, 

473 
Dicerca  divaricata,  267 
Dichelia  siilfureana,  ^380 
Dicromorpha  viridis,  *I4I 
Dictyopteryx,  73 
Diedrocephala    mollipes , 

170 
Diestrammena  marmorata, 

Differential     locust,     *I37. 

Digestive  epithelium,  cells 
of,  of  crane-fly,  *I7 

Digger-wasps,   463 

Dimorphic,  469 

Dineutes  emarginata,  *257 

Diopsidse,  Diopsis  (<^i,  di, 
two;    o-tf-'ic:   opsis,  eyes), 

347 

Dioptidse  (  p  r  o  b .  "if, 
dis,  twice ;  oi/'if,  opsis, 
seen,  referring  to  the 
two  generations  per  year 
in  some  forms),  407 

Diplosis  pini-radiata,  *324 

Diptera  (f^t,  di,  two; 
nrepov,  ptcrum,  wing), 
56,  301 ;  genuina,  303 ; 
life-history  o  f  ,  302 ; 
mouth-parts  of,  302 

Dipterous  larvae,  histo- 
blasts  or  imaginal  discs 
of,  47 

Directive  coloration,  607 

Discal  area  or  spot  or  cell 
(near  center  of  base  of 
wing) 

Diseases,  insects  in  rela- 
tion to,  615 

Dissostcira  Carolina,  *i4i, 
143 ;  brain  of,  *22 ;  ner- 
vous system  of,  *22 ; 
pericardial  membrane  of, 
*i8;  respiratory  system 
of,  *i8 


Diverse-land  geometer, 
*399 

Dixa-flies,  304 

Dixa  sp.,  *3i9;  larva  of, 
*3i8;  mouth-parts  of, 
*3i9;  pupa  of,  *3i9;  ve- 
nation of  wing  of,  *320 

Dixidas,  Dixa  (prob.  f^'sof, 
dixus,  double,  or  ^cl^ii, 
dixis,  a  showing,  dis- 
play), 304,  319 

Dobson-fly,  *326;  alimen- 
tary canal  of,  *i6;  head 
of,  showing  mouth-parts, 
*6 

Dobsons,  55 

Docophorus  calif orniensis, 
116;  communis,  116, 
*i20,  122;  cursor,  116; 
excisus,  116;  icterodes, 
116,  *ii9;  lari,  116;  per- 
tusus,  117;  platystoy- 
nius,   116 

Dog-  and  cat-flea,  *354 

Dog-day  locusts,  167 

Dog-louse,   sucking,   *2i7 

Dolichopodid,  venation  of 
wing  of,  *336 

Dolichopodidae,  Dolicho- 
pus  (fSoAfjoTTotjf,  doliclio- 
pus,  with  long  feet),  332, 
335 

Dolichopus  lobatus,  *335 

Dorcus  parallclus,  273 

Dorsal  (backward,  oppo- 
site of  ventral) 

Dorsal  vessel,  valves  of, 
*i8;  of  locust,  *i7 

Doryphora  lo-lincata,  *278 

Dorypteryx,  113 

Double-eyed  sphinx,  *435, 
437 

Dragon-flies,  S3,  75 ;  col- 
lecting nymphs  of,  87; 
colors  of,  80 ;  distribu- 
tion of,  78;  egg-laying 
of,  82;  food  of,  81;  life- 
history  of,  84;  preserv- 
ing adults,  88;  rearing 
nymphs  of,  87 ;  struc- 
ture of,  79 ;  table  for 
classification,  89 

Dragon-fly,  *76 ;  circula- 
tory system  of,  *i7; 
giant,  stages  in  develop- 
ment of,  *83  ;  hero,  93  ; 
nymph  of,  *76,  *77 ;  ve- 
nation of  wing  of,  *89; 


Index 


657 


water-prince,  *9S ;  wind- 
sprite,  *96 
Drosophila       ampelophila, 

349 
Drosophilidse,     Drosophila 
((5/3(5(70f,     drosus,   dew; 
<pi\oq,  p  hilu  s ,  loving) , 

349 
Dynastes  grantii,  276 ;  her- 

cules,  276;    tityrus,   *I2, 

*276,  *277 
Dysdercus  suturcllus,  210 
Dyspcptcris       abortivaria, 

*397,    398 ;    venation   of, 

*396 
Dyticus,  *2S5,  *256 
Dytiscidae,        D  y  t  i  s  c  u  s 

{^vTiKog,    dyticus,  fond  of 

diving),  252 
Dyticidae,  252 

Earwigs,  53,  162,  *i62 
Echocerus  maxillosus,  289 
Ecitomyia  whcclcri,  *S53 
Eciton  caecum,  *543 ;  opa- 
citherce,     543;     schmitti, 

*543 
Ecitoxenia  breviples,  *552 
Ecpanthcria  deAorata,  413; 

miizina,  413 
Ectobia     germanica,     128, 

*I28 

Egg,  development  of,  of 
water  scavenger-beetle, 
*38 ;  fertilization  of,  14  ; 
of  fish-moth,  develop- 
ment of,  *4o;  of  saw- 
fly,  development  of,  *39 ; 
tubes,  *248 

Egg-case  o  f  cockroach, 
*I27;  of  Hydrophilus 
triangularis,   *259 

Eggs,  micropyle  of,  *37 ; 
of  Anopheles  sp.,  *3o6; 
of  Culex  incidens,  306; 
of  katydid,  *I49 

Elaphidion  villosum,  285 ; 
stages  of,  *284 

Elatcr  acerrimus,  larva  of, 
*268 ;  nigricollis,  268 ; 
rubricollis,  268 ;  san- 
guinipcnnis,  268 

Elateridse,  Elater  (f^arrip, 
elater,  driver),  266,  267 

Eleodes,  *288 

Elephantiasis  and  mos- 
quitoes, 633 

Elm-leaf  beetle,  278 


Elipsocus,  113 

Elytra,  249 

Embia  texana,  *I09 

Embiidse,  Embia  (e/ifito^, 
embius,  living,  viva- 
cious), 109 

Embryo,  37 

Einesa  longipcs,  204,  *205 

Emesidae,  Emesa  (Emesa, 
city  of  Syria),  195,  204 

Empididse,  Empis  (efJ^Trtg, 
empis,  mosquito),  332, 
334 

Empis.  335 

Empodium  (appendage  be- 
tween two  tarsal  pul- 
villi) 

Enchenopa  binotata,  168 ; 
gracilis,  *i6g 

Encoptolophus  sordidus, 
*I4S,  146 

Endropia  armataria,  *399 

Ennonos  subsignarius,  398 

Ensign-flies,  463 

Entomobryidse,  Entomo- 
brya  (prob.  evTo/nov,  cn- 
tomum,  insect ;  (ipvov, 
bryuni,  moss),  62, 

Entomophilous  flower,  566 

Epargyreus  tityrus,  442 ; 
venatioii  of,  *440 

Ephemerida,  Ephemera 
(e^T/fiepog,  cphcmcrus, 
for  a  day),  53,  54,  65 

Ephestia  kuehniella,   *377, 

379 
Ephydra,  347 
Ephydridse,       Ephydra 
(ecpvilpog,    ephydrus,    liv- 
ing on  the  water),  348 
Epiivschna  hcros,  93 
Epicauta  c  in  e  r  e  a  ,  293  ; 
pcnnsylvanica,  293 ;  vit- 
tata,  *2go,  293 
Epicccrus    imbricatus,    295 
Epicordulia  princeps,  *95 
Epidapus  scabies,  325 
Epimartyria,    371 
Epimenis,   grape-vine,   409 
Erax   cincrasccns,   mouth- 
parts  of,  *33i ;  venation 
of  wing  of,  *33i 
Erebia,  457 
Erebus  odora,  401 
Erctmoptera  broivni,  *3ii 
Ergates    spiculatus,    *282, 

284 
Eriocampa  cerasi,  466 


Eriocephala,  371 
Eriocephalidae,    E  r  i  o  c  e  - 
phala    (prob.  i/piov,    eri- 
um,    mound  ;     Kecpa/y, 
cephale,  head),  368 
Eristalis   sp.,    mouth-parts 
of,  *340 ;  t  e  n  a  X ,  *339, 
340 
Erynnis  sassacus,  443 
Erythroncura  comes,  *i7o; 
vitis,    170;   vulnerata, 
*I70 
Eubyia  cognataria,  *398 
Euclca  delphinii,  384 ; 

pccnulata,  384 
Eucleidae,  Euclea     (euKXeia, 

euclca,  glory),  384 
Eudamus  proteus,  442 
Eudemis  botrana,  381 
Eudryas  grata,  *409,  410 
Eiigonia    calif ornica,    456 ; 

j-album,  456 
Eumacaria       brunneraria, 

*398 
Eumenes,  498 ;  vase  mud- 
nest  of,  *499 
Eumenidse,   Eumenes    ( f^v, 
eu,  good ;   fievog,   menus, 
disposition),  498 
Euphoria  inda,  276,  *2'jy 
Euphydryas  phaeton,  456 
Euplectrus  comstockii,  485 
Euplexoptera       ( ev,       eu, 
well ;  ttIeko,   plcco,  fold- 
ed ;     TTTEpdv,   p  t  e  r  u  m  , 
wing),  53,  162 
Eurymetopus,   118 
Eurymus  eurytheme,  446 ; 

philodice,  446 
Eustigmc  acrcca,  415 
Euthrips  tritici,  221 
Euvanessa  antiopa,  455 
Evaniidse,  Evania    {evcivlo^, 
euanius,    taking    trouble 
easily),  463 
Exoprosopa  sp.,  ^334 
Exoskeleton,     4 ;     attach- 
ment of  muscles   to,   *4 
Exuvia,     186;     of     stone- 
fly  nymph,  *7i 
Eye,   of  horsefly,   *3i ;   of 
moth,   *3i ;   of  Lasio- 
canipa   quercifolia,    *22 ; 
of  Catocala  nupta,  *32 ; 
of      May-fly,      *32;      of 
blow-fly,  *3;i ;  spots,   PI. 
X.,   I 
Eyed  grayling,  457 


658 


Index 


Eyes,  compound  and  sim- 
ple, 30;  of  May-flies, 
*69 ;  of  net  -winged 
midges,  *3i6 

Eye  -  spotted  bud  -  moth, 
*38i 

Fall  canker-worm,  397 

False  crane-flies,  Z'^l 

Family,  56 

Feather-wings,  376 

Femur,  *3,  *6 

Fcniscca  tarquinins,  444 

Fermenting  fruit-flies,  349 

Fertilization  of  egg,  14 ; 
of  plants,  564 

Fig-insect,    *487 

Figitidae  (figo,  to  attach  by 
piercing),  475 

Figs,  caprification  of,  487 ; 
on  a  branch,  ^488 ;  show- 
ing effect  of  non-caprifi- 
cation  and  of  caprifica- 
tion, *489 

Filariasis  and  mosquitoes, 
632 

Filiform,  364 

Fireflies,  265,  269 

Fish-moth,  *58,  *62;  de- 
velopment of  egg  of,  *40 

Flannel-moths,  369 

p-Iat-bug,  195.  208,  *209 

Fleas,  56 

Flesh-fly,  343.  *344 

Flies,  56;  life-history  of, 
302 ;  mouth-parts  o  f  , 
302 ;  the  two-winged, 
301 

Flower-bug,  195,  *209;  in- 
sidious,  206 

Flower-fly,  332,  *339 

Flower,  pistil  and  ovary 
of,  showing  pollen  tube, 
*564 

Flowers  and  insects,  562; 
colors  of,  developed  for 
attraction  o  f  insects, 
566;  cross-pollinated  by 
humming-birds,  573 ;  en- 
tomophilous,  570 

Food-habits  of  Hemiptera, 
164,  165  ;  variety  of,  8 

Footman,  banded,  410 ; 
painted,  409;  pale,  410; 
striped,  409 

Footman-moths,   370,  409 

Foot  of  house-fly,  *34i 

Forest-fly,  *352 


Forest-moths,  eight-spot- 
ted, *4o8 

Forest  tent-caterpillar 
moth,  *4i7 

Fork-tailed  katydid,  *I52 

Formica  cxscctoidcs,  545 ; 
nitidrivcntris,  547;  san- 
guinea,  547 ;  schauftissi, 
547 ;  subocncsccns,  547 ; 
subscricca,  547 

Formicina  (see  For  mi - 
coidea),  463,  539;  key  to 
families  of,  540 

Formicoidea,  Formica 
{fonnica,  ant),  539 

Frenat3e  {f  r  c  n  u  in  ,  that 
which  holds  things  to- 
gether), 368 

Frenulum,  *376 

Fritillaries,  456 

Frog-hoppers,   170 

Froth  production  of  frog- 
hoppers,  stages  of,  *i7i 

Fruit-worms,    parasite    of, 

*485. 

Fulgoridae  (Fulgora,  god- 
dess of  lightning),  166, 
168 

Fungus  attacking  chinch- 
bugs,  212 

Fungus,  parasitic,  of  Cali- 
f  o  r  n  i  a  flower-beetle, 
^346 

Fungus  -  gnat,  304,  324, 
*325 ;  venation  of  wing 
of,  *325 

Gadflies,  328 

Galcrncclla  luteola,  stages 
of,  *278 

Galgulidge,  Galgulus  (gal- 
gtilus,  a  small  bird),  194, 
202 

Galgulus  oculata,  *202 

Gall,  blackberry,  473 ;  fi- 
brous, of  the  California 
live-oak,  ^472;  of  the 
California  white  oak, 
*473;   rose,  473 

Gallcria  mcllonclla,  379 

Gall-flies,  56,  463,  467;  al- 
ternation of  generations 
of,  469 

Gall-fly,  *468 ;  ovipositor 
of.  *468 

Gall-forming  aphids,    180 

Gall-gnats,  304 

Gall-midge,  322 


Galls,  467  ;  growth  of,  474 ; 
juinping,  of  the  oak, 
*473  ;  made  by  a  Cynipid 
gall-fly,  *469 ;  on  leaf, 
*47i ;  on  leaf  of  Califor- 
nia white  oak,  *470 ;  on 
twigs  of  California  white 
oak,  *47i  ;  trumpet,  on 
leaves  of  California 
white  oak,  *47o;  variety 
of,  470 

Ganglia,  21 

Gastropaclia  amcricana, 
416,  *4i8 

Gastrophilus  e  qui ,  337, 
*338 ;  nasalis,  338 

Gclechia  cercalella,  375 ; 
gallce-solidaginis,  350 ; 
pinifoliclla,  376 

Genus,  56 

Geometer-moths,  396 

Gcoinctra  iridaria,  398 

Geometrid  moth,  larva  of, 
*395,  *396;  larva  of,  in 
protective  position,  *6o3 

Geometrid,  venation  of  a, 
*396 

Geometrina,  Geometra  {,yv, 
ge,  earth  ;  fierpov,  me- 
tnim,  measure),  370, 
396 

Gcotrupes,  275 

Geotrupes  excrementi, 
275  ;  opaciis,  275  ;  splen- 
didns,  275 

Ghost-moths,   372 

Giant-skippers,    441 

Giebelia,   118 

Gills  of  young  May-fly, 
68 ;  tracheal,  20 ;  of  May- 
fly, nymph,  *20 

Girdler,  currant-stem,  *465 

Gloveria  arizoncnsis,  base 
of  scale  of,  *59i  ;  scales 
from  wing  of,  *593 

Glow-worm,  269 

Goatweed-butterfly,  455 

Golden-eyed  fly,  *228 

Gomphidse,  G  o  m  p  h  u  s 
{yofi<pog,  gomphiis,  a  fast- 
ening), 92 

Goiuphus  cxilis,  92 

Goniodes,  118 

Goniocotes,  118;  holo- 
gastcr,    119 

Goniotauliiis  dispectus, 
243 

Gopher    crickets,    155 


Gossamer-winged     butter- 
flies, 443 
Gnophccla  latipennis,  407 
Grain-cephus,      European, 

467 
Grain-weevil,  297 
Granddaddy-long-Iegs,  321 
Grape-berry  moth,  381 
Grape-phylloxera,  172,176; 
various   forms  of,   *I76, 
177 
Grape-vine  amphion,  *438 ; 
flea-beetle,     larva     of, 
*28o ;   roots   infested   by 
phylloxera,      *I78 ; 
sphinx-moth,  *434 ;  root- 
borer,  391 
Grapholitha  scbastiance,  383 
Grapta   sp.,   part   of   wing 
o  f ,     showing    insertion 
pits  of  scales,  *590 
Grasshoppers,    long- 
horned,  126,  149 
Grass-stem  flies,   350 
Grass-thrips,   221 
Green  fly  of  gardens,   172 
Green-fruit   worms,    *402 ; 

parasitized,   *486 
Greenhead,   *328 
Green-leaf  insect,  *6o2 
Green-striped    locust,    144, 

*I45 

Grouse-locusts,    136,    147 

Gryllidce,  Gryllus  (grylhis, 
cricket),  126,  157 

Gryllafalpa  borcalis,  161 ; 
Columbia,   161 

Gryllus  abbrcviatus,  *is8; 
assimilis,  158 ;  domesti- 
cus,  *I58;  luctuosus, 
158 ;  pcnnsylvanicus, 

*I57 

Guest  bumblebee,  519 

Gypsy-moth,  405 

Gyrinidje,  Gyrinus  (  yvplvoq, 
gyrintis,  a  circle,  a  whirl- 
pool), 252,   255 

Gyrinus  mariims,  larva  of, 
"*257 

Gyropidse,  Gyropus  (yvpog, 
gyrus,  crooked ;  TTovg, 
pus,  foot).  118 

Gyropus,  118,  121 

Hsemamoeba,  malaria-pro- 
ducing, development  of, 
in  human  blood-corpus- 
cle, *6i8 


Index 

Hccmatopinus  acanthopus, 
218;  antcnnatus,  218; 
asini,  218;  curystcrnus, 
217,  *2i8;  ovis,  *2i9; 
pcdalis,  218;  pilifertis, 
*2I7;  sciuroptcri,  218; 
spinulosus,  218;  sutu- 
ralis,  218;  urius,  *2i8; 
vcntricosus,  218 ;  vituli, 
217 

Hadanucus  subterrancus, 
156   . 

Ha  genius   brcvistylus,   92 

Hag-moth,  384 

Hair-streaks,  444 

Hair,  tactile,  innervation 
of,    *26 

Halesidota  argcntata,  414 ; 
carya,  *4i4 ;  lobecula, 
414;  maculata,  *4i4;  sp., 
larvae  of,  *4ii;  tcsse- 
lata,  *4i4 ;  tessclata, 
caterpillar  of,  *4i3 ;  tes- 
sclata, venation  of,  *4i6 

Halcsns  indistinctiis,   *24l 

Halictus,  517 

Halobates,  198 ;  wUllers- 
dorfR,  *I97 

Halteres.  302 

Haltica  chalybca,  larva  of, 
*28o 

Handmaid-moths,  392 

Haploa  c  I  y  m  c  11  c  ,  414 ; 
contigua,  *AiS ',  fulvi- 
costa,  *4i5 ;  Iccontei, 
414 

Harlequin-fly,  alimentary 
canal  of,  *I5 ;  part  of 
sympathetic  nervous  sys- 
tem of,  *24 

Harpalus  pennsylvanicus, 
255 

Harrisina  amcricana,  387 ; 
coracina,  387 ;  mctallica, 
387 

Harvester,  444 

Harvest-flies,  167 

Hawk  -  moth,  369,  431 ; 
posed  before  jimson- 
weed,  *572 

Head,  interior  of,  of  Mon- 
arch butterfly,  showing 
arrangement  of  pharynx, 
oesophagus,  etc.,  *36i ; 
of  dobson-fly,  parts  of, 
*6 ;  of  locust,  showing 
anatomy,  *I24;  parts  of. 


659 


Head-louse,   *2i6 
Hearing,  sense  of,  29 
Heart,  16;  of  locust,  *I7; 

valves  of,  *i8 
Heel-flies,  338 
Hcliconia  sp.,  scales  from 

wing  of,  *594 
Heliothis  armigcra,   404 
Hellgrammite,  226 
Hemaris  brucci,  439 ;   dif- 

iinis,     larva     of,     *438; 

thysbe,  438 
Hemerobiidae,  Hemerobius 

{iifiEpoftiog,      hemerobius, 

ephemeral),   224,  229 
Hemerobius  sp.,  *229,  230; 

sp.,  larva  of,  *230 
H enter oeanipa  leucostigma, 

degenerating  muscle   of, 

*50 
Hemilcuca     clectra,     425; 

maia,    425 ;    nevadensis, 

425 
Hemiptera     {viJ-i,     h  e  m  i , 
half  ;    TTTspnu,    ptcrum, 
wing),  55,  163;  as  pests, 

163.  165,  169,  172,  176, 
180,  194;  classification 
of,   165  ;  food  habits  of, 

164,  165 ;  key  to  sub- 
orders of,  165 ;  meta- 
morphosis  of,  164 ; 
mouth-parts  of,  164 ; 
section  through  head  and 
beak,  *i64 

Hen-flea,  356 

Heodes     hypophlaas,     444 

Hepialidse,       H  e  p  i  a  1  u  s 

(fjTTialog,   h  e  p  ial  US  ,  a 

ghost    moth),    368,    370, 

372 
Hepialus  gracilis,  venation 

of  wing  of,   *372 ;   nwg- 

lasliani,  scale  of,  *589 
Hespcria  tessellata.  442 
Hesperid,      venation     o  f, 

*440  _ 
Hesperidse,      H  e  s  p  e  r  i  a 

(Hesperus,      evening 

star),  442 
Hesperotettix       pratcnsis, 

*i40 
Hessian   fly,  323 ;   parasite 

of,  *478 
Hetserina,    89;    amcricana, 

*90 
Hetcrocarnpa        guttivitta, 

*393 ;  larva  of,  *394 


66o 


Index 


Heterocera  (erepoc,  hete- 
r  u  s  ,  different ;  Kepac, 
ceras,  horn),  364 

Heteromera  (Irepog,  h  e  - 
terus,  different ;  fiepog, 
merus,  part),  252;  key 
to  families  of,  288 

Heteroptera  (Irepog,  hc- 
tcrns,  different;  Tzrepov, 
pterum,  wing),  166,  194; 
key  to  families  of,  194 

Hexapoda,  3 

Hibernia  tiliaria,  *397 ; 
larva  of,  *396 

Hilara,  335 

Hippiscus  tigrinus,  *I43; 
tiiberculatus,  144 ;  fe- 
male of,  *I42;  young  of, 

*I42 

Hippobosca     equina,     351, 

*352 
Hippoboscidae,  Hippobosca 

(tTTTTo,    hippo,    horse  ; 

^<j(jk6?,  b  0  s  c  u  s  ,  feed) , 

351 
Hippodamia      convergens, 

*286 
Histoblasts    of    Dipterous 

larvae,  *47 
Histogenesis,   49 
Histolysis,  49 
Hives,     observation,     for 

studying  honey-bee,  *53i, 

*532 
Hccmatobia    serrata,     342, 

*343 
Hog-louse,  *2i8 
Holcaspis  centricola,  471 ; 

globulus,  472 ;  in  anis  , 

Holorusia  rubiginosa, 
anatomy  of  larva  of, 
*2i ;  degenerating  mus- 
cle from  pupa  of,  *50 ; 
development  of  wing- 
buds  of,  *48;  salivary 
glands,  before  and  after 
degeneration,  of  larva 
of,  *5i ;  salivary  gland 
of,  *i6;   stages  of,  *322 

Hoinolomyia      canicularis , 

345 

Homoptera  {ppdg,  homus, 
same ;  ■n-repov,  pterum, 
wing),  165;  key  to  fam- 
ilies of,  166 

Honey-ant,  545 

Honey-bee,   *52i ;   alimen- 


tary canal  of,  *S29 ; 
brood-comb  with  young 
stages,  *46 ;  comb,  brood 
cells,  *523 ;  building 
comb,  *527 ;  developing 
muscle  in  pupa  of,  *5i; 
development  of  mouth- 
parts,  *46o;  East  Indian, 
comb  of,  *520 ;  first  tar- 
sal segment  ,of  hind  legs 
of,  *528 ;  gathering  pol- 
len and  nectar,  *522 ; 
head  and  mouth-parts 
of,  *7 ;  honey-making 
by,  528 ;  larva  and  adult, 
*45 ;  leg  of,  *52i ;  life- 
history  of,  521 ;  mouth- 
parts  of,  *459 ;  section 
of  body  of  pupa  of, 
showing  histolysis  and 
histogenesis,  *49 ;  sec- 
tion of  ocellus  of,  *3o; 
stages  in  development  of 
nervous  system  of,  *24 ; 
sting  of,  460,  *46i ; 
swarming  of,  525 ;  ven- 
tral aspect  of  abdomen 
of  worker,  *527 ;  visit- 
ing A  s  c  1  e  p  i  a  s,  *574 ; 
wax-making  by,  526 

Honey-dew  of  Aleyrodidse, 
192;  of  aphids,  175,  180; 
of  black  scales,  187 

Honey-making  by  honey- 
bee, 528 

Hop-merchants,  454 

Horn,  caudal,  *432 

Hornet,  bald-faced,  506 ; 
nest,    single-comb,    *5o8 

Horn-fly,  342,  *343 

Horn-tails,  463,  466 

Horse-fly,  327,  *328;  cor- 
neal facets  of  compound 
eye  of,  *3i ;  mouth-parts 
of,  *329 ;  venation  of 
wing  of,  *328 

Horse-louse,  218 

Horse-stinger,  76 

Horse-tick,  351;  *352 

Host,  479 

House-crickets,   157 

House-flea,  *354 

House-fly,  *34i,  342;  foot 
of,  *34i ;  larva  of,  *342 ; 
mouth-parts  of,  *8,  *30i ; 
nervous  system  of,  *22 ; 
pupa  in  puparium  of, 
*342 


Hover-flies,  339 

Human  flea,  356 

Humming-bird   moth,    431 

Humming-birds,  cross-pol- 
linating flowers,  573 

Hyaliodes  vitripennts,  210 

Hydrobatidae,  Hydrobates 
(^v6up,  hydor,  water  ; 
(iaTTi^,  bates,  one  that 
treads),  195,  196 

Hydro charis  obtusatus, 260 

Hydrophilidae,  Hydrophi- 
lus  {v6(op,  hydor,  water; 
(plXog,  philus,  loving), 
256,  258 

Hydrophilus,  development 
of  egg  of,  *38;  external 
anatomy  of,  *247;  inter- 
nal anatomy  of,  *248; 
triangularis,  *259 ;  trian- 
gularis, egg-case  of, 
*259;  triangularis,  larva 
of,  *259 

Hydropsychidas,  Hydro- 
psyche  (v6up,  hydor, 
water  ;  ipvxTJ,  psyche, 
butterfly),  244,  245 

Hydropsyche,  243 ;  sca- 
lar is,   *242 

Hydroptilidse,  Hydroptila 
(v6up,  hydor,  water ; 
T^rilov^ptilum,  feathers), 
244,  245 

Hygrotrechus,  196,  *I97 

Hylotoma  berberidis,  de- 
velopment of  egg  of,  *39 

Hymenoptera  {vf^vv,  hy- 
men, membrane ;  tttepov, 
pterum,  wing),  56,  459; 
aculeate,  490;  key  to 
groups  of,  463 ;  mouth- 
parts  of,  460;  parasitic, 
476 ;  sting  of,  460 

Hyperites,   113 

Hypermetamorphosis,  200; 
of  Epicauta  vittata,  290 

Hyperparasitism,    482 

Hyphantria  cunea.  412 

Hypodcrma  bovis,  338 ; 
lineata,  338 

Hypoprepia  fuscosa,  409; 
miniata,  409 

Hydroporus,    255 

Icerya  purchasi,  attacked 
by  Australian  lady-bird 
beetle,  *i87 ;  male  and 
female  of,  *i86 


Index 


66  I 


Ichneumon-flies,  56 
Ichneumonidse,  Ichneumon 
(ichneumon,   ichneumon 

fly),  463  ,        ,  ^ 

Ichneumonoidea  (see  Ich- 
neumonidse),  477 

Ichneumons,  463 

Imaginal  discs  of  Dipter- 
ous larvae,  *47 

Imago   (adult) 

Imperial-moth,  426 

Inchworm,  in  protective 
position,  *6o3 

Inchworms,  395 

Indian  Cetonia,  276;  meal- 
moth,  378 

Inocellia,  233 

Inquilines,  475 

Insect,  properly  pinned  up, 

*637 
Insecta,  3 

Insect-killing  bottle,  *635 
Insects,  simplest,  52 
Instincts  of  ants,  554 
lo     Emperor,    424,     *425 1 

larva  of,  ^426 
Iphidides  ajax,  449;  «»«''- 

celliis,  449;  telamonides, 

449 

Iris  versicolor,  visited  by 
insects,  568 

Isabella  tiger-moth,   412 

Ischnocera  (prob.  'lc!Xvoq> 
ischnus,  thin,  thread- 
like; Kepa^,  ceras,  horn), 
key  to  genera  of,  118 

Ischnoptera  pcnnsylvanica, 

*I28 

Isoptera  (}<yoQ,  isus,  equal ; 
■KTEpov,    pterum,    wing), 

55.  99 
Isopteryx,    73 
Isosoma  hordei,  487 
Ithobalus  a  Cauda,  450; 

polydamas,  450 

Janus  integer,  *465 
Japanese  locust,  *iS5 
Japygidse  (Japyx,  mythical 

progenitor  of  Japyges  of 

southern    Italy),   60,    61 
Japyx     sp.,     *62;     subter- 

raneus,  *6i 
JassidcC,  Jassus   (lassus,  a 

town  in  ancient  Caria), 

166,   169 
Jerusalem     cricket,     *is6, 

157 


Jigger-flea,  355 
Jimson-weed,     hawk-moth 

posed  before,  *572 
Jugatae      (juguni,     yoke), 

368 
Jugum,  368 
Jumping  plant-lice,  171 
June-bugs,  273,  *27S 
Junonia  cania,  455 

Kallinia  sp.,  *6oi 
Katydid  and  eggs  of,  *I49 
Key.  53 

Killing-bottle,  for  collect- 
ing insects,  how  to  make, 

635 
Kissing-bug,  203 

Labels,  for  collected  in- 
sects, 637' 

Labellum,  *8 

Labeo  longifarsis,  *479 

Labia  minor,  *i62 

Labidura  riparia,  162 

Labium  (see  mouth-parts) 

Labrum  (see  mouth-parts) 

Lace-bug,  hawthorn,  208 

Lace-bugs,  195,  207 

Lace-wing  fly,  *228 

Lachnosterna  fusca,  *275 

Ladybird  -  beetle,  *286 ; 
Australian,  186,  *i87 

Laemobothrium,  119;  loo- 
misi,  122 

Lcertias  philenor,  450 

Lagoa  crisp ata,  383 

Lake-flies,  65 

Lamellate,  *250 

Lamellicornia  (lamella, 
thin  plate;  cornu,  horn), 
251,  272 

Lamp-chimney  breeding- 
cage,  *642 

Lampyridae,  L  a  m  p  y  r  i  s 
(Xdfnrovpii,  lampuris,  a 
glow  worm),  265,  269 

Lance-tailed     grasshopper, 

*I54 
Lantern-flies,  168 
Laphria,  331 
Lappet-moth,       American, 

*4i8 
Lappet-moths,  416 
Largus  succinctus,  *2io 
Larridae,  Larra  (Fabricius, 

— derivation    unknown), 

500 


Larva,  44  ;  coarctate,  291 ; 
of  a  phorid  fly  attached 
to  the  larva  of  the  ant, 

*553 
Lasiderma  serricorne,  271 
Lasiocanipa        quercifolia, 

ommatidia  of,  *32 
Lasiocampidae,       Lasio- 
canipa     (Adfftof,      lasius, 
hairy ;    Kd/intj,    campe,    a 
caterpillar),  370,  415 
Lasius  brunneus,   175,  545 
Lateral   (to  right  or  left) 
Leaf-beetles,  277 
Leaf-bug,  four-lined,  *209 ; 

predaceous,  *2o6 
Leaf-bugs,  195 
Leaf-chafers,  273,  275 
Leaf-cutter    bee,    nest    of, 

*5i4 
Leaf-hoppers,  169 
Leaf-insects,  132 
Leaf-miners,  375 
Least  skipper,  443 
Leather-jackets,  321 
Lebia  grandis,  255 
Lccanium  olece,   187 
Lecanium    scales    attacked 

by  Cordyceps  clavulata, 

*i88 
Leg,    section    of,    showing 

muscles,  *5 
Legs  of  beetles,  *250 
Lcistotrophus     cingulatus, 

261 
Lema  trilineata,  278 
Lcmonias  virgulti,  444 
Lens  of  ocellus  of  larva  of 

saw-fly,  *30 
Leopard-moth,  413 
Lcpidocyrtus    americanus, 

*64 

Lepidoptera  (AeTrtf,  lepis, 
a  scale ;  i^repSv,  pterum, 
wing),  56,  358;  life-his- 
tory of,  360;  mouth- 
parts  of,  359.  *362; 
scales  of,  their  structure 
and  arrangement,   589 

Lepinotus,   113 

Lepisma  saccharina,  *58, 
61,  domestica,  *62 ;  sp.. 
*62 ;  sp..  development  of 
egg  of,  *40 

Lepismidae,  Lepisma 
(Mniafia,  lepisma,  scaly), 
60;  key  to  genera  of,  61 

Leptidae,    Leptis     (AeTrrov, 


662 


Index 


leptus,    thin,    fine,    deli- 
cate), 327,  330,  3Z2 
Leptoceridse,       Leptocerus 
(AfTTTof,     leptus,    thin, 
fine,    delicate ;      Ktpag, 
ceras,  horn),  244 
Leptocerus  resurgens,  *240 
Leptocoris  trivittatus,  *2i3 
Leptogcnvs   elongata,   540, 

*54i 
Leptoglossus        oppositus, 

214;  phylloptis,   214 
Leptoterna  dolobrata,  210 
Leptothorax  cmersoni,  544 
Lesser     migratory     locust, 

133,  *r37,  141 
Lestes  sp.,  nymph  of,  *84; 

uncata,  *%7 
Leucania    unipuncta,    404 ; 

larva  of,  on  corn,  *403 
Leuctra,  74 
Libellula  basalis,  94 ;  pul- 

cliella,   93,    *94 ;    quadri- 

inactilata,  94;  scmifasci- 

afa,  *94.  95 
Libellulidse,    Libellula 

(libcllitlns,  a  tiny  book), 

91.  93 
Libuniia  lenttilenta,  para- 
site of,  *479 
Lice,  216 

Lightning-bugs,  269 
Ligyrus  rugiceps,  276 
Lime-tree      canker-moths, 
*397 ;    inch-worm,   *S96 
Limnephilidae,     Limnophi- 
lus  Q-i/iivT],    limnc,  a  pool ; 
(f)i?iog,  philus,  loving) ,  244 
Limnobatcs    Uncata,    *i97, 

198 
Limnobatidee,    Limnobates 
(?ii/j.i^V,     limnc,    a    pool ; 
jiarriq,    bates,   one   that 
treads),  194 
Liodcrma  ligata,  214 
Liotheidse     Q^eloq,      liu  s  , 
smooth;  Qelv,  then,  run), 
118 
Lipeurus,      118;      baculus, 
*I20,    121;    fcrox,    122; 
foriicidatus,     117;     for- 
Hciilatiis,       development 
stages    of,    *ii5;    vari- 
abilis,  119 
Lipoptena  cervi,  352 
Litliosia   bicolor,  410 
Lithosiidse,  Lithosia   (At5of, 
lithus,  a  stone),  370,  409 


Live-cage  bell-jar,  *642; 
meat-safe,  *643 

Live-oak  moth,  407 ;  scale, 
California,  *i9i 

Locust,  alimentary  canal 
of,  *I4;  auditory  organ 
of,  *28 ;  brain  of,  *22 ; 
development  of  wings 
of,  *42 ;  development 
stages  of,  *42 ;  external 
parts  of,  *3 ;  head,  ner- 
vous system  of,  *2S ; 
head  of,  showing  anat- 
omy, *I24;  heart  or  dor- 
sal vessel  of,  *I7;  ner- 
vous system  of,  *22; 
pericardial  membrane  of, 
*i8;  respiratory  system 
of.  *i8 

Lociista  viridissima,  nerve- 
endings  in  tip  of  maxil- 
lary palpus  of,   *26 

Locustidse,  Locusta  (lo- 
custa,  locust),  126,  149; 
wingless,  154 

Locusts,  53,  126,  133 ;  au- 
ditory organs  of,  *I35 ; 
impaled  by  shrike,  *I34; 
life-history  of,  136;  key 
to  subfamilies  of,  136; 
migratory  species  of, 
133 ;  sounds  of,  134 

Locust-tree  carpenter- 
moth,  385,  *386 

Long-horned    locust,    *I46 

Long-legged  flies,  332,  335 

Long-tailed  skipper,  442 

Loopers,  395 

Lopidca  media,  210 

Lorquins  Admiral,  452 

Louse,  sheep-foot,  218 

Lucanidse,  Lucanus  {lu- 
cerc,  shine),  272 

Lucanus  dania,  273 ; 
claplius,   *273;   placidus, 

273 
Lucilia   cccsar,   344 ;   vena- 
tion of  wing  of,  *344 
Luna-moth,  420,  *422 
Lycrena,  443;   sp.,  part  of 

wing  of,  *590 
Lycsenid,       venation       of, 

*440 
Lycfenidas,     Lycsena 

(?imaiva,    lye  ana,   a   she 

wolf),  443 
Lycomorpha    cons  tans. 

scale    of,    *592;    grotci, 


410 ;  miniata,  410 ;  plio- 
lus,  410 
Lyctocoris  iitchi,  *2o6 
Lyda,  466 

Lyggeidse,  Lyseus   (  Avyalog, 
lygaiis,    shadowy),    195, 
207,  211 
LygcEus  tureieus,  *2ii 
Lygus  pratensis,  *2og 
Lymantriidae     ( IvfiavTi/pioq, 
lymanterius,         destruc- 
tive), 370,  404 

Machilis,  62;  polypoda, 
nerve-endings  in  tip  of 
labial  palpus  of,  *26;  sp., 
*63 

Macrodactylus  subspino- 
sus,    *27S 

Maia  moth,  424 

Malaria-carrying  m  o  s  - 
quito,  *3o8 

Malaria,  mosquitoes  and, 
617 

Malaria-producing  Htema- 
mceba,  development  of, 
in  human  blood-corpus- 
cle, *6i8 

Mallodon,  284 

Mallophaga  (jj^alMq,  mat- 
ins, hair,  wool ;  (payeiv, 
phagcn,  eat),  55,  iii; 
distribution  of,  116,  117; 
keys  for  classification, 
118;  life-history  of,  114; 
oesophageal  sclerite  of, 
115;  pharyngeal  sclerite 
of,*ii6;  structure  of,  115 

Malpighian  tubules,  14 

Mandible  (see  in  0  u  t  h  - 
parts) 

Mantidse,  Mantis  (/^avng, 
mantis,  a  prophet),  126, 
129 ;  ancient  beliefs  con- 
cerning, 130 

Mantis  religiosa,  *i2g,  130, 
131 ;  egg-cases  of,  *i62, 
*i65 

Mantispa  styriaca,  234 

Mantispidae,  Mantispa  (ir- 
regular, fiavTiQ,  mantis, 
an  insect;  utp,  ops,  face), 
224,  234 

Maple-scale,  *i88 

Maple-tree  borer,  stages 
of,  *284 

Maracanda,  232 

March-flies,  304,  325 


Index 


663 


March-fly,  *326 
Margarodes     formicarum, 

190 
Maritime  locust,   *I47 
Marsh-treader,  *I97,  198 
Marsh-treaders,   194 
Marumba  modcsta,  437 
Masaridee,  M  a  s  a  r  i  s 

(fxaado/xai,    masaomce,  to 
chew),  498 
Mason-bees,  514 
Mason-wasps,  498 
May-beetles,  275 
May-flies,    53,    65 ;    about 
electric  lamp,  *66 ;  gills 
of   nymph    of,    68 ;    life- 
history  of,  67 
May-fly,     *68 ;     compound 
eye  of,  *32 ;   nymph  of, 
showing    tracheal    gills, 
*20 ;      section      through 
head  of  male,  *69  ;  young 
nymph  of,  *67 
Maxillae     (see     m  0  ut  h  - 

parts) 
Meadow-browns,  457 
Meadow      grasshopper, 

*I53,  *I54 
Mealy-winged     flies,     166, 

190,     *I93 ;     respiratory 

system  of,  *i9 
Meat-safe  live-cage,  *643 
Mecoptera    (/J-r^Kog,     mectis, 

length ;    nrepdv,    pterum, 

wing),  223,  235;  key  to 

genera  of,  235 
Media   (see  venation) 
Mediterranean  flour-moth, 

*377,  379 
Megachile,     514;     anthra- 

cina,  nest  of,  *5i4 
Megachilidae,        Megachile 

(fieyac,    incgas,  great  ; 

Xt'iT^og,    chelus,  lip),   514 
Megalopyge     c  r  is  p  at  a  , 

scales,     from     wing    of, 

*593 ;   opercularis,  383 
Megalopygidse        (  p  r  o  b  . 

fieyag,    in  e  g  a  s  ,    great ; 

nvyi],    pyge,  rump),  369, 

383 
Megathyma  yucca,  441 
Megathymidse        (  p  r  o  b  . 

fieyag,     m  e  g  a  s  ,    great ; 

6v/u6g,      thymus,    spirit), 

441 
Megilla     maculata,     *286; 

vitigera,  *286 


Melanactes  piccus,  268 
Melanoplus     atlanis,     133, 
*I37,      141 ;      bivittatus, 
*I38,   141 ;  differcntialis, 
*I37, 141 ;  femur-rubrum, 
*I35,    140;    development 
of,  *42 ;  nervous  system 
of  head  of,  *23 ;  postem- 
bryonic  development  of, 
*i25;  spretus,  133,   136 
Melipona,  520 
Melissodes,  515 
Melittia  ceto,  391 
Melitcca   cJialcedon,   457 
Mcloe  angusticollis,  293 
Meloidse,    M  e  I  o  e     (Lin- 
naeus,— etym.  uncertain), 
288,  289 
Melophagus    ovinus,    351, 

*352 

Membracidae,      Membracis 

{fiefijipa^,      membrax,     a 

kind  of  cicada),  166,  168 

Membrane  of  wing  {outer 

half    of   fore-wing,   He- 

tcroptcra,   *I96) 

Mcmythrus     polistiformis, 

391 
Menopon  pallidum,  *ii9 
Mcrisus  destructor,  *478 
Merope,  236 

Mcsochorus    agilis,    para- 
sitizing Xylina  sp.,  *486 
Mesothemis    simplicicollis, 

97 
Mesobregma  cincta,  *I47 
Meso-thorax,  7 
Metal-marks,  444 
Metamorphosis,    35 ;    com- 
plete,   41 ;    complete,    of 
blow-fly,  *45 ;  complete, 
of  honey-bee,  ^46 ;  com- 
plete,   of   monarch    but- 
terfly,     *44 ;      complete, 
significance    of,    51 ;    in- 
complete,     41 ;      incom- 
plete,   of    a    dragon-fly, 
*83 ;    incomplete,   of  as- 
sassin-bug,  *43 ;   incom- 
plete, of  Melanoplus  fe- 
mur-rubrum,    *i25 ;     of 
Hemiptera,  164 
Metapodius     femoratus, 

214 
Meta-thorax,  7 
Meteor  us    hyphantrice, 
*485 ;    parasitizing    Xy- 
lina  lacticinerea,  *487 


Mexican  jumping  bean- 
moth,  382,  *383 

Microccntrum  laurifolium, 
*I5I,  152;  retinervis,  152 

Micropterygidse,  Microp- 
teryx  {fiiKpdg,  micrus, 
small ;  Trrt-pvi,  pteryx, 
wing),  368,  370,  371 

Micropteryx  sp.,  venation 
of  wing  of,  *372 

Microdon  mutabilis,  larva 
of,  *340 

Micropyle,  15;  of  various 
eggs,  *37 

Midaidae,  Midas  ( //Mac, 
midas,  a  destructive  in- 
sect in  leguminous 
plants),  330 

Midas-flies,  330 

Midge,  larva  of,  *3ii; 
male,  *3io;  pupa  of, 
*3ii 

Midges,  304,  310 

Migratory   locusts,    133 

Milkweed-bug,    211 

Milkweed-butterfly,  a  r  - 
rangement  of  pharynx, 
oesophagus,  etc.,  in  head 
of,  *36i ;  cross-section 
of  sucking  proboscis  of, 
*36i  ;  part  of  maxillary 
proboscis  of,  showing 
arrangement  of  muscles, 
*36i 

Milyas  cinctus,  204 

Mimesidae,  Mimesa 
(/lifXTjatg,  mimesis,  imi- 
tation), 502 

Mimicry,  609 ;  of  monarch 
butterfly  b  y  viceroy, 
*6io ;  of  wasps  by  moths, 
*6o8 

Mining-bees,  513  ' 

Mochlonyx  cu  liciformis, 
auditory  organ  in  an- 
tenna of,  *29 

Mode  of  pinning  beetle, 
*637 

Modest  sphinx,  437 

Mole-cricket,  long-winged, 
161 ;  northern,  161 ;  Por- 
to Rican,  *i6i 

Monarch  butterfly,  *45i  ; 
complete  metamorphosis 
of,  *44 ;  development  of 
color-pattern  in  pupal 
wings  of,  *S96 ;  external 
parts    of,     *6;     internal 


664 


Index 


anatomy  of,  *I3;  larva 
of,  *6o5 ;  mimicry  of,  by 
viceroy  butterfly,  *6io ; 
part  of  wing  of,  show- 
ing scales,  *36o;  vena- 
tion of  wings  of,  *37i ; 
venation  of,  *ll 

Moniliform,  258 

Monobia  quadridens,  502 

Monohammus,  285 

Monomorium  minutum, 
*536;  pharaonis,  541 

Monostegia  rosce,  466 

Monterey-pine  midge,  *324 

Morpho  sp.,  base  of  scale 
of,   *59i 

Mosquito,  auditory  organ 
in  antenna  of,  *2g;  beak 
of,  *302 ;  female,  mouth- 
parts  of,  *30i ;  head  and 
mouth-parts  of,  *7 ;  life- 
history  of,  *30S ;  mala- 
ria-carrying, *3o8 

Mosquitoes,  304 ;  and  ele- 
phantiasis, 633 ;  and  fila- 
riasis,  632 ;  and  malaria, 
617;  and  yellow  fever, 
630 ;  eaten  by  dragon- 
flies,  81 ;  methods  of 
fighting,  309 

Moth,  ommatidia  of,  *3i 

Moth-fly,  319,  *320;  larva 
and  pupa  of,  *320 ; 
mouth-parts  of,  *320 

Moth-like  flies,  304 

Moths,  56,  358;  and  but- 
terflies, single  scale 
from,  *589;  and  wasps, 
showing  mimicry,  *6o8; 
key  to  superfamilies  and 
families  of,  367 ;  scales 
of,  their  structure  and 
arrangement,  589 ;  wood- 
nymph,   407 

Moulting,  43 

Mourning-cloak,  455 

Mouth-parts,  6 ;  head  of 
larva  of  net-winged 
midge  showing  forma- 
tion of  adult,  *3i8;  head 
of  larva  of  black-fly 
showing  developing, 
*3i4;  developing,  of  tus- 
sock-moth, *363 ;  devel- 
opment of,  of  Corydalis 
cornuta,  *227;  of  bee- 
fly.  *334;  of  dance-fly, 
*335 ;  of  Cicada,  *g ;  of 


Dixa  sp.,  *3I9;  of  dob- 
son-fly,  *6;  of  Eristalis 
sp-,  *340;  of  female 
black-fly,  *3I3;  of  fe- 
male net-winged  midge, 
*3i6;  of  a  female  mos- 
quito, *30i ;  of  a  female 
punkie,  *3ii ;  of  Hemip- 
tera,  *i64;  of  honey-bee, 
*7,  *459;  of  honey-bee, 
development,  *46o ;  of 
horse-fly,  *329;  of  house- 
fly, *8,  *30i ;  of  Hymen- 
optera,  460;  of  larva  of 
black-fly,  *3i3;  of  larva 
of  net-winged  midge, 
*3i7;  of  larva  of  wasp, 
*46i ;  of  Lepidoptera, 
*362 ;  of  a  long-tongued 
bee,  *5i2;  of  mosquito, 
*7;  of  moth-fly.  *32o; 
of  mud-wasp,  *46o;  of 
net-winged  midge,  *9 ; 
of  robber-fly,  ^331 ;  of  a 
short-tongued  bee,  *5ii; 
of  sphinx-moth,  *io;  of 
thrips,  *8,  *22o;  variety 
of,  8;  of  wasp,  devel- 
opment of,  *46o,  *46i 

Mud-nest,  vase,  of  Eume- 
nes  sp.,  *499 

Mule-killer,  76 

Murgantia  histrionicOj  214, 

*2IS 

Musca  domestica,  *34i, 
342 ;  larva  of,  *342 ; 
mouth-parts  of,  *8,  *30i ; 
pupa  in  puparium  of, 
*342 

Muscardine,  412 

Muscid,  aquatic,  *348 

Muscidae,  Musca  (t^vla, 
myia,  a  fly),  332 

Muscinae,  341,  342 

Muscle,  degenerating, 
from  pupa  of  giant 
crane-fly,  *S0 ;  degen- 
erating, of  tussock-moth, 
*50 ;  developing,  in  pupa 
of  honey-bee,  51;  struc- 
ture of,  *I3,  *I4 

Muscles,  arrangement  of, 
in  maxillary  proboscis 
of  milkweed  butterfly, 
*36i ;  attachment  of,  to 
body-wall,  *4;  of  leg, 
*5;  of  wing,  *5 

Muscular  system,  13 


Mutillidx,  Mutilla  {mu- 
tilo,  to  crop  short),  497 

Mycetophilidae,  Myceto- 
phila  (j^yK7}(j,  myces,  a 
fungus ;  ^('Aof,  philus, 
loving),  304,  324,  *325; 
venation  of  wing  of,  *325 

Mydas  luteipennis,  330 

Myodocha   serripes,   211 

Myopa,  337 

Myopsocus,  113 

Myriapoda,  3 

Myrmecocystus  melliger, 
545 

Myrmecophila,  161 ;  ne- 
brascensis,  *i62 

Myrmecophily,  552 

Mrymeleon,  232 ;  adult, 
*23i ;  sp.,  larva  and 
sand-pit  of,   *230 

Myrmeleonidae,  Myrme- 
leon  (fivpfiTjt  myrmex, 
ant;  Muv,  lean,  lion), 
224,  230;  key  to  subfam- 
ilies of,  231 

Myrmica  hrevinodes,  544 

Myrmicidae,  Myrmica 
(fivpfiTj^,  myrmex,  ant), 
540,  541 

Mystacides,  243 

Mytilaspis  pomorum,  189 

Myzus  cerasi,  174 


Nabidae,    N  a  b  i  s    {nabis, 

camelopard),    195 
Nobis  fusca,  *205 
Nathalis  iole,  446 
Naucoridae,     N  a  u  c  o  r  i  s 

(vavg,    naus,  ship ;    nopig, 

coris,  a  bug),  194,  199 
Necrobia  ruHpes,  270;  vio- 

lacea,  270 
Necrophorus     marginatus, 

*26l 

Nectar,  566 

Nectar-drinking,  adapta- 
tion of  insects  for,  569 

Negro-bug,  flea-like,  215 

Negro-bugs,   195 

Nematocera  (vfj/ia,  nema, 
thread  ;  fcepaf,  ceras, 
horn),  303;  key  to  fam- 
ilies of,  304 

Nematus  erichsonii,  466 ; 
ventricosus,  466 ;  larva 
of,  *465 

Nemobius  fasciatus,  form 


Index 


665 


vittatus,   *I59;    chirping 
of,  159 
Nemoura,   74 
Ncophasia  menapia,  445 
Nepa,  201 
Nepidae,    Nepa    {nepa,   a 

scorpion),  194,  201 
Nerve  endings  in  labial 
palpus  of  Machilis  poly- 
poda,  *26 ;  in  maxillary 
palpus  of  Locusta  viri- 
dissima,  *26 
Nerve-winged  insects,  223 
Nervous  system,  20 ;  in 
head  of  locust,  *23 ;  of 
house-fly,  *22 ;  of  locust, 
*22 ;  of  midge,  *22 ; 
stages  in  development 
of,  of  honey-bee,  *24 ; 
stages  in  development 
of,  of  water-beetle,  *25  ; 
sympathetic,  23  ;  of  larva 
of  harlequin-fly,  *24 

Nest,  artificial,  for  ants, 
*550 ;  communal,  of  yel- 
low-jacket, Vcspa  sp., 
*505 ;  Fielde,  for  ants, 
*55i  ;  Janet,  for  ants, 
*550,  *55i ;  of  Califor- 
nia honey-ant,  546;  of 
Camponotus  pcnnsyl- 
vanicus,  *545 ;  of  bum- 
blebee, *5i9;  of  leaf-cut- 
ter bee,  *SI4;  of  a  mud- 
dauber  wasp,  *499 ;  of 
Vcspa  crahro,  *504;  of 
western  agricultural  ant, 
*542;  of  yellow-jacket, 
Vcspa  sp.,  cut  open  to 
show  combs  within,  *5o6 

Nest-building  of  wasps, 
508 

Nest-burrow  of  Ammophi- 
la,  *494 ;  of  Astata  imi- 
color,  *500 ;  of  Oxybclus 
quadri-notatus,  *49i ;  of 
short-tongued  mining- 
beetle.  *5i6 

Nesting-grounds  of  Am- 
mophila,    *492 

Nests,  for  rearing  ants, 
548 

Nest-tunnel  of  carpenter- 
bee,  *5i3 

Nest-tunnels  of  two  car- 
penter-wasps,   *502 

Net,  for  collecting  insects, 
how  to  make,  635 ;  wa- 


ter, for  collecting  drag- 
on-fly nymphs,  *87 
Net-winged  midge,  cross- 
section  of  body  of  larva 
of,  *3i5  ;  cross-section  of 
eyes  of,  *3i7;  female, 
*3i6 ;  female,  mouth- 
parts  of,  *3i6;  head  of 
larva  of,  showing  forma- 
tion of  adult  head-parts, 
*3i8;  heads  of  male  and 
female  of,  *3i6;  larva  of, 
*3i5;  mouth-parts  of, 
*9 ;  mouth-parts  of  larva 
of,  *3i7;  pupa  of,  *3i5; 
venation  of  wing  of, 
*3i7 

Net-winged  midges,  304, 
314 

Neuroptera  (vevpov,  neu- 
runi,  nerve  ;  nTspov, 
pterum,  wing),  55,  223; 
key  to  families  of,  224 

Ncsara  pcnnsylvanica,  214 

Nicoletia   tcxcnsis,    *6i 

Nirmus,  118;  fclix,  *I2I, 
122;  lincolatiis,  116;  pi- 
Icus,  117;  prcEstans,  *ii4 

Nitzschia,    119 

Noctuidse,  Noctua  (noctua, 
a  night  owl),  370,  399 

Nomadidse,  N  o  m  a  d  a 
{vofiag,  nomas,  nomad) 
455 

Nomctettix  parvus,  *I48 

"No-see-ums,"  310 

Notodonta  stragula,  *392 

Notodontid,  venation  of, 
*392 

Notodontidse,  Notodonta 
(vuToc,  notiis,  the  back ; 
660VC,  odus,  tooth),  369, 
392 

Notolophus  leucostigma, 
405 ;  developing  mouth- 
parts  of,  *363;  larva  of, 
*405 

Notonecta,  199 

Notonectidje,  Notonecta 
(lyroQ,  notiis,  the  back  ; 
vTJKTTig,  ncctcs,  a  swim- 
mer),  194,   198 

Notum  (dorsal  wall  of  a 
body  segment) 

Number  of  insect  species, 
56 

Nycteribiidge,  Nycteribia 
{vv  KTepi(;,    nycteris,    a 


bat;  /3/of,  bius,  life), 
351,  352 

Nycteribia  sp.,  352 

Nymph  (young  of  insects 
with  incomplete  meta- 
morphosis), *42,  *67 

Nymphalid,  venation  of, 
*440 

Nymphalidae,  Nymphalis 
(vvijcpTi,  ny  m p  h  e  ,  a 
nymph),  450 

Oak      bucculatrix  -  moths, 

376 
Oak  leaf-roller,  380 
Oak-apples,  471.  *472 
Oak-scale,    southern    Cali- 
fornia,  *I92 
Oak-worm   moth,    orange- 
striped,  *428 
Oblique-banded  leaf-roller. 

380 
Oblong  leaf-winged   katy- 
did, *i5i 
Obsolete-banded  strawber- 
ry  leaf-roller,    larva   of, 
*364 ;    pupa    and    adults 
of,  *365 
Ocellar    lens    of    larva    of 

saw-fl3\  *30 
Ocellus,  *3,  31 ;  section  of, 

of  honey-bee,  *30 
Ocncria  dispar,  405 
O  d  o  n  a  t  a    (6(^ovg,    odus, 
tooth,    applicability    un- 
certain), 53,  75 
Odontomachus  hccmatodes, 

340 
Odontomyia,    venation    of 

wing  of,   *329 
Odynerus,  499 
CEcanthus      angustipennis, 
160  ;  f  a  s  c  iat  II  s,  *I59, 
*i6o;  nivcus,  *I59,  160 
CEdcmasia   concinna,   394 ; 
eximia,   *393 ;    larva   of, 
*393 
Qidipodinse,  136,  143 
(lEneis,  457 

Qistridas,  Oistrus  (oiarpoc, 
ccstrus,    a    gadfly,    a 
sting),  332,  337 
Oikcticus  abbotti,  386 
Oil-beetles,  289 
Olfcrsia   americana,    351 
Ommatidium,  *3i,  *32,  *33 
Omus,  253 
Oncomyia,  337 


666 


Index 


Oncopeltus  fasciatus,  211 

Oncophorus,  118 

Onion-fly,   345 

Onion-thrips,    221 

Onychophora,  3 

Opiiion  piirgatmn,  *482 

Opsiccctus  personatus,  203 

Orange-puppy,  450 

Orange-scale,  188,  *i89, 
*igo 

Orange-sulphur,  446 

Orange-tips,  446 

Orchelimum  vulgare,  *i53, 
*I54 

Orders,  key  to,  52 

Orl-fly,  smoky,  immature 
stages  of,  *225 

Orncodcs  hexadactyla,  Zll 

Orneodidje,  Orneodes 
(opreov,  onieum,  bird ; 
el6og,    eidos,  form),   368 

Orphnephilidae  (  p  r  o  b  . 
"op^vri,  orphne,  darkness ; 
(piloQ,  philus,  loving),  327 

Orphnephila  testacca,  2^7 

Orphiila  pclidina,  *i4i 

Orthoptera  (op66c,  or  thus, 
straight ;  ■n-repov,  ptcrum, 
wing),  5,  123;  key  to 
families  of,  126 ;  sound- 
making  by,  123,  134,  150, 
*i5i,  152,  155,  *i57,  159 

Orthosoma  brimnca,  283 ; 
development  of  color- 
pattern  in,  *598 

Orchids,  specialization  of, 
for  insect  pollination, 
575  _ 

Oscinidas,  Oscinis  (La- 
treille,  —  etym.  uncer- 
tain), 350 

Osmia,   514 

OtiorhynchidcC,  Otiorhyn- 
chus  (uTiov,  otium,  little 
ear ;  ^vyxoc,  rygchus, 
snout),  294,  29s 

Otiorhynchus  ovatus,  295 

Ovarial    tubes    of   Aptera, 

*59. 

Ovaries  and  oviducts  of 
thrips,  *36 ;  of  queen  bee, 
*S2i 

Ovipositor,  *3,  7 ;  of  a  gall- 
fly. *468 

Owl-butterfly,  *6i2 

Owlet-moths,  370 

Ox-louse,  long-nosed,  217; 
short-nosed,  217,  *2i8 


Oxybelus  quadri-notatus, 
nest-burrow  of,  *49i 

Oxyptilus  pcriscelidacty- 
l^^,  377  >  tcnuidactylus, 
*377 

Pachycondyla  harpax,  540, 
*553 

Painted  beauty,  454 

Palcacrita  vcrnata,  397 

Pale-green  locust,  *I40 

Palmer-worm,  larva  of, 
*373 ;  moth,  *374 

Palpi  (jointed  processes 
attached  to  mouth-parts 
or  terminal  segments  of 
abdomen) 

Palpus,  nerve-endings  in 
tip  of,  *26 

Pamphilas,  443 

Paviera  longula,  211 

Panorpa,  236 ;  rufescens, 
^236 

Panorpodes,  236 

Paonias  cxcoccatus,  *435 ; 
myops,  *435 

Papilio,  448 

Papilio  cresphontes,  449 ; 
dauniis,  449 ;  Euryme- 
don,  449 ;  glaucus,  449 ; 
polyxenes,  450;  venation 
of,  *440 ,  rutiilus,  *447, 
449 ;  sp.,  chrysalid  of, 
*448;  troilus,  450;  tur- 
mis,   449 

Papilionid,  venation  of, 
*440 

Papilionidas,  Papilio  {pa- 
pilio, a  butterfly),  447 

Papilionina  (see  Papilion- 
idse) 

Papiriidae  (prob.  naTrvpog, 
papyrus,  paper,  reed), 
63  ■ 

Papirius  maculosus,  *63 

Parandra  brunnea,  285 

Parasa  chloris,  384 

P  a  r  a  s  i  t  a  (parasitus,  a 
parasite),  165,  216 

Parasite,  chalcid,  *479 ; 
ichneumon,  of  army- 
worms,  *482 ;  ichneu- 
mon, of  the  pigeon-tre- 
mex,  *484 

Parasites,  importation  of, 
486;  Hymenopterous,  of 
a  social  wasp,  *48o ; 
numbers     of,     480 ;     of 


aphids,  *I73;  of  caterpil- 
lars, *476,  *477 

Parasitic  fungus  of  Cali- 
fornia flower-beetle,  *346 

Parasitic  Hymenoptera, 
476 

Parasitism,  characteristics 
of,  478;  of  caterpillar, 
*476,  *477 

Paratcttix  cucullatus,  *I48 

Parnassian   butterfly,   *43g 

Parnassians,  447 

Parnassius  clodius,  447 ; 
sviiiitheus,   447,   *439 

Parnidse,  Parnus  (Fabri- 
cius,  1792, — etym.  doubt- 
ful), larva  of,  ^264 

Parorgyia  parallcla,  405 

Parthenogenesis,  221; 
among  aphids,   173,  175 

Passalus  cornutus,  273 

Pastinaca  sativa,  visited 
by  insects,  569,  571 

Patagia,    408 

Patterns  of  insects,  advan- 
tages   of,    584 

Peach-tree  borer,  389 ;  lar- 
va of,  *39i ;  cocoons  and 
empty  pupal  skins  of, 
*39i ;  moths  of,  *390 ; 
eggs  of,  *390 

Peacock  butterfly,  455 

Pear-tree  flea-louse,  171 ; 
slug,  466 

Pea-weevil,  277,  *28i 

Pectinate,  *25o 

Pediculidae,  P  e  d  i  c  u  1  u  s 
(pediculus,  a  louse), 
216 

Pediculus  capitus,  *2i6 ; 
inguinalis,  *2i7 ;  vesti- 
menti,  *2i6 

Peduncle,  loi,  534 

Pcgomyia  vidua,  345 

Pelecinidse,  P  e  1  e  c  i  n  u  s 
{nE7,Eidvoq,  pelccinus,  a 
pelican),  463,  484 

Pelccinus      polyturator , 

*485 
Pelidnota  punctata.  275 
Pellucid  locust,  133,  *I45 
Pclocaris  femorata,  199 
Pelopceus,  499 
Pemphigus  t  ess  el  lata,  180 
Pemphredonidae,  Pemphre- 

don  {iTEfKppe^uv,  peniphre- 

don,   a   kind   of   wasp), 

502 


Index 


667 


Pentamera    (ttevts,     pcnte, 

five;  iJ-tpng,  j/trrMj,  part), 

251,  252 
Pentatomidse,      Pentatoma 

{nevTE,     p  e  n  t  e  ,     five  ; 

Ta/iEcv,    tanien,  cut),  195, 

207,  214 
Pentatoma      junipcrina , 

*2I5 

Pepper-and-salt  currant- 
moth,  *398 

Pcpsis  formosa,  *500,  501 

Pericardial  membrane  of 
locust,   *i8 

Pericoiiia  calif ornica,*320; 
larva  and  pupa  of,  *320 

Pericopidae  (^rfp/,  peri, 
around  ;  Konreiv,  copten, 
ciit),  370,  407 

Periplaneta  americana, 
127 ;  australasia,  128 ; 
orientalis,  128,  *I28 

Peripsocus,    113 

Perithcmis  domitia,  *95, 
96 

Perla,  J3 ;  sp.,  *72 

Pernicious  scale,  females 
and  young  on  bark  of 
fruit-tree,  *i82;  male 
and  female  (enlarged), 
*i84;  on  bark  of  fruit- 
tree,  *i8i ;  structure  and 
life-history  of,   182 

PctropJwra    divcrsilineata, 

*399 
Phagocytes,  49 
Phagocytosis,  49 
Phaneiis  carnifcx,  *274 
Phasmidje,  P  h  a  s  m  a 

{(pacfia,     phasma,  an  ap- 
parition),  126,   132;  key 
to  genera  of,    132;   pro- 
tective   resemblance    of, 
132 
Pheidolc    cominufafa,    sol- 
dier and  worker  of,  *537  ; 
lamia,  soldier  and  work- 
er of,   *535 
Phigalia  strigataria,  *398 
Philopteridas,     Philopterus 
((ptAEiv,     philen,    love; 
TTTepov,  pferuntj  a  feath- 
er), 118 
Philosamia   cynthia,  421 
Phlcgcthontius  sexta,  434 ; 
Carolina,  larva  of,  *432 ; 
celeiis,    larva    of,    *432 ; 
quinqiiemaculata,  434 


PhobctroH  pithccium,  384 
Pholisora  catallus,  442 
P  h  0  I II,  s   achemon,   *433, 

434;  larva  of,  *43i,  *434; 

pandorus,  *433,  434 
Phorbia  brassiccc,  345 ;  ce- 

parum,  345 
Phorothvips  sp.,  *2r9 
Photiniis    angulatus,    269; 

nwdcstus,  larva  of,  *26g; 

pyralis,  269;  scintillans, 

*269 
Phryganca  cincrea,  *239 
Phryganeidse,      Phryganea 

{_^pv}avm>,       pliryganum, 

a  dry  stick),  244,  245 
Phryganidia       calif  ornica, 

*4o6,  407 
Phyllium,   132,  *6o2 
Phylloxera  vastatrix,  176 
Phyllum,  2 
Phyniata  zvolii,  205 
Phymatidse,      P  h  y  m  a  t  a 

((pv/j,a,    phyma,  a  tumor), 

195 
Physocephala,  237 !  affiyiis, 

*336 
Physonota    unipunctata, 

281 
Physostomum,  119 
Phytophaga    (<Pvt6v,     phy- 

tum,  plant ;   <paynv,  pha- 

gen,  eat),  252,  277 
Pierid,  venation  of,  *440 
Pieridse,      Pieris      ( Trieplg, 

picris,    sing,    of    TriepiSeg, 

the  Muses),  444 
Pigeon-tremex,   *467 ;   ich- 
neumon-parasite of,  *484 
Pimpla   conqiiisitor,   *483 ; 

inquisitor,    483 ;    sp.,    an 

ichneumon-fly,   *48i 
Pinacate  bug,  *288 
Pine-leaf     miner,     376; 

white,   445 
Pinning    beetle,    mode    of, 

*637  ;  bug,  *637  ;  insects, 

637 
Piophila  casei,  *348 
Pipe-vine  swallowtail,  450 
Pistil  and  ovary  of  flower, 

showing    pollen-tube, 

*564 
Plagionottis      speciosus, 

*283,  284 
Planta,  522 
Plant  -  bug,      leaf  -  footed, 

214 ;  tarnished,  *209 


Plant-lice,   171 
Plants,  fertilization  of,  564 
Plathcniis  lydia,  *97;   tri- 
maculata,     issuance     o  f 
adult,  *86 
Platycercus  quercus,  273 
Platygaster  herricki,  larva 
of,  *48i ;  instricator,  lar- 
va of,  *48i 
Platynota  Havedana,  *38i 
Platypsylla  eastoris,  265 
Platypsyllidce,      Platypsyl- 
lus      {nXarvg,     p  I  a  t  y  s  , 
broad,   flat ;  tpv^'Aa,  psyl- 
la,  flea),  265 
Plecoptera    (7rAeKr<5f,    plec- 
tus,    plaited  ;    Trrepdv, 
pterum,     wing), 53,     65, 
70 ;   table   of   genera,   73 
Plodia  interpunctella,  378 
Plum-curculio,  296 
Plume-moth,       California, 

*377 
Plume-moths,  368,  376 
Plum-geometer,  *398 
Plusia,  402 

Podisus  spinosus,  *2i5 
Podura     sp.,     young    and 

adult,   *4i 
Poduridae,    Podura     {Trovg, 

pus,    foot;   ovpa,    ura, 

tail),  63,  64 
Pccciloeapsiis  lineatus,  *2og 
Pogonomyrmex     barbatus 

var.     molifaciens,     541 ; 

occidentaiis,  mound-nest 

of,  *542 
Polistes,  294,  503,  506,  507 ; 

sp.,  nest  and  stages  of, 

*5o8;    parasitized    by 

Xenos  sp.,  *293 
Pollen,  basket,  514,   *52i ; 

gathering,  adaptation  of 

insects  for,  569 
Pollination,   564 
Polybia,  503;  llavitarsis,  507 
Polycrgus  rufesccns.  547 
Polygonia    comma,    *453 ; 

interrogationis ,    454; 

chrysalid  of,  *455  ;  larvae 

of,  *454  . 
Polymorphism,  526 
Polyphemus  -  moth,       420, 

*42i ;  larva  of,  *42i 
Polyphylla  crinita,  *274 
Polypsocus,   113 
Polystwchotes     punctatus, 

*22g 


668 


Index 


Pomace-flies,  349 
Pompilidse,     P  o  m  p  i  1  u  s 

{-cifiTTt/,  pompe,  escort), 

499.  501 
Poneridae,  Ponera  ( Trow/pdf, 

poncrns,    bad,    useless), 

540 
Pontia  bcckeri,  445 ;  napi, 

445 ;     occidentalis,    445 ; 

pro  to  dice,  445  ;  venation 

of,  *440 ;  rapce,  445 ;  si- 

syinbri,   445 
Poplar  carpenter-moth,  385 
Potter-bees,  514 
Potato-beetle,  278 
Potter-wasps,  498 
Pofoinanthus    hrunneus, 

section  through  head  of 

male,  ^69 
Praying-mantes,    126;    an- 
cient beliefs  concerning, 

130 
Praying-mantis,  *I29,  130, 

131 ;  egg-cases  of,  *i62, 

*i63 
Predaceous     diving-beetle, 

252 ;  ground-beetle,  252 
Prenolcpis    imparis,    547 ; 

underground  nest  of, 

*546 
Prionidse,  Prionus    (Trpiiov, 

pyion,  a  saw),  283 
Prionidus   cristatiis,   204 
Prionoxystus  robinicc,  385, 

386 ;    scales    from    wing 

of,    *594;    venation    of, 

*38 
Prionus  calif ornicus,  *282 ; 

imbricornis,  283 ;  laticol- 

lis,  283 
Pristophora      grossularice, 

466 
Proboscis,  *7,  8,  *io 
Proctotrypidse,         Procto- 

trypes  (Trpw/crof,    proctus, 

the  anus  ;  rpvirav,  trypan, 

to  bore),  463,  477 
Proctotrypoidea  (see 

Proctotrypidse) 
Prolimacodcs  scapha,  384 
Promethea  -moth,     422, 

*424 ;     development     of 

color-pattern     in     pupal 

wings  of,  *S97 
Prominents,  369,  392 
Pronotum,  *3 
Pronuba  moth  laying  eggs 

in  ovary  of  Yucca,  *577 ; 


I      rubbing    pollen    down 
i      stigmatic  tube  of  Yucca, 
i      *578      . 
I  Pronuba   yuccasella,    as    a 

cross-pollinator   of  yuc- 
cas, 576 
Prop-legs,  360 
Propolis,   530 
Prosopis     pubescens, 

mouth-parts  of,  *5ii 
Prosternum,  136 
Protective        resemblance, 

599;  of  Phasmidas,   132; 

of  Trimerotropis,  147 
Prothorax,  7 
Pselaphidse,    Pselaphus 

{■>liTjAa(pdv,      psclapJian, 

feel     or    grope     about), 

265 
Pscudohazis      cglantcrina, 

426  ;   h  e  r  a  ,   426 ;   shas- 

tansis,  426 
Pseudoperla,  jt, 
Psilopiis  ciliatus,  venation 

of  wing  of,  *336 
Psinidia  fenestralis,  *i46 
Psithyridse,    Psithyrus 

(ipidvpd^,   psithyrus, 

whisperer,      warbler), 

520 
Psithyrus,  519 
Psocidae,    Psocus    (ip^x^^'^i 

psochen,      grind      in 

pieces),      112;     key     to 

genera  of,  112;  venation 

of  wing  of,  113 
Psocus,   113 
Psyche,  386 
Psyche     carbonaria,     386 ; 

confederata,     386;     glo- 

veri,  386 
Psychidje,     Psyche     {i'vxv, 

psyche,   a  butterfly) , 

369,  386 
Psychoda  sp.,  mouth-parts 

of,  *320 
Psychodidse,  Psychoda 

( fvxn,     psyche,    butter- 
fly;   eldoc,    edus,    form), 

304,  319 
Psychology  of  insects,   32 
Psychoniorpha      epimenis, 

409 
Psyllidse,     Psylla     {rpvTCka, 

psylla,  a  flea),  166,  171 
Psylloinyia  testacea,  *553 
Pteronarcys,  JS 
Pterophorida;,      Pteropho- 


rus    {T^-repdv,  p  t  e  ru  m  , 

feathers ;  (pepeiv,   pheren, 

bear),  368,  376 
Pteroptrix  Havimedia,  *47g 
Pterostichus,  255 ;  storiola, 

*254 
Ptinidas,      Ptinus      ((pOivu, 

phthino,  decay,  destroy), 

265,  271 
Ptynx,  233 
Pulcx  avium,  353  ;  irritans, 

*354,  356 
Pulicidae,     Pulex     (pulex, 

a  flea),  355,  356 
Pulvilliform,  332 
Pulvillus,  102 
Pulvinaria     innumerabilis , 

*i88 
Punkie,      female,      mouth- 
parts  of,  *3ii 
Punkies,  310 
Pupa,  45 
Pupipara   (pupus,  a  child ; 

parcre,  bring  forth),  303, 

351 

Puss-moth,  larva  of,  *6o7 

Puss-moths,  392,  394 

Pyralid  moth,  venation  of 
wing  of,  *376 

Pyralidina,  Pyralis  (^''p, 
/'.v;-,  fire),  368,  374,  376 

Pyralis  farinalis,  378 ;  ve- 
nation of  wing  of,  *376 

PyromorpJia  d i m idiata  . 
388;  venation  of,  *389 

Pyromorphid,  venation  of 
a,  *389 

Pyromorphidas  (prob.  Tt'p, 
pyr,  fire ;  i^opipy,  morphe, 
form),  369,  386 

Pyrrharctia  isabclla,  412 

Pyrrhocoridae,  Pyrrhocoris 
(■rrvppdc,  pyrrus,  red- 
dish :  KopLg,  coris,  a  bug), 
195,  207,  210 

Radius  {see  venation) 
Ranatra  fusca,  *20i ;  eggs 

of,  *20I 
Raphidia    sp.,     stages    of, 

*233 

Raphidiidae,  Raphidia 
(^a<pk,  rapJiis,  a  needle), 
224 

Raspberry  geometer,  398; 
plume-moth,  *377 ;  root- 
borer,  391 

Rat-fleas,  357 


Index 


669 


Rat-tailed  larva  of  a  Syr- 

phid,  *340 
Rearing  insects,  directions 

for,  640 
Redbugs,  195,  *2io 
Red-humped       caterpillar- 
moth,     *393 ;     larva    of, 

*393,  394 
Red-legged     locust,     *I35, 

140 
Red-spotted  purple,  452 
Red-tailed  tachina-fly,  *347 
Reduviidae,  Reduvius   (re- 

duvia,  a  hangnail),  195, 

203 
Reflexes  of  ants,  554 
Remedies,   189 
Reproduction  among 

aphids,    173,    177 
Reproductive  system,  14 
Reproductive    organs,    38 ; 

of  female  thrips,  *36 
Resemblance,       protective, 

599 

Respiration,  19 ;  of  aquatic 
insects,  20 

Respiratory  system,  19 ;  of 
Aptera,  *59;  of  locust, 
*i8 ;  of  mealy-winged 
fly,  *I9;  of  thrips,  *i8 

Rlia^iuiii  lineatum,  larva 
of.  *266 

Rhagolctis  cingidata,  larva 
of,  *349  ;  puparia  of,  *35o 

Rliainnus  lanccolata,  vis- 
ited by  insects,  569 

Rhamphomyia,  335  ;  longi- 
cauda,  *334;  sp.,  mouth- 
parts  of,  *335 ;  venation 
of  wing  of,  *335 

Rhinoceros  -beetle,  *I2, 
*276 

Rhoditcs  roscu,  473 

Rhopalocera  {^o-na'kov,  rho- 
pahiiii,  a  club;  K^pac, 
ccras,  a  horn),  364 

Rlwpotota  vacciniana,  *38i 

Rhyacophilidse.  R  h  y  a  - 
c  o  p  h  i  1  a  ((ii'aky  ryax,  a 
stream  ;  (pi^e'iv,  p  hil  c  n , 
love),  244,  245 

Rhynchophora,  251,  294; 
key  to  families  of,  294 

Rhyphidse,  Rhyphus  (  ^vp6g, 
rhynts,  curved),  327 

Rhyphus,  diagram  of  wing 
of,  *327 

Rice-weevil,  297 


Robber-flies,  330 

Robber-fly,  *33i ;  bumble- 
bee-like, *33i ;  mouth- 
parts  of,  *33i-;  venation 
of  wing  of,  *33i 

Rocky  Mountain  locust, 
133.  136 

Rose-beetle,  *275 

Rose-leaf  hopper,  170 

Rose-aphids  and  ants,  *I74 

Rose-scale,  *i90 

Rose- slug,  466 

Rostrum,   251 

Rosy  dryocampa,  427 

Rove-beetles,  260,  *552 

Royal  walnut-moth,  larva 
of,  *366 

Russet-brown  tortrix,  *38i 

Saddle  -  back      caterpillar, 

384 

Salda  sp.,  *202 

Saldidse,  Salda  (from  a 
proper  name),  195,  202, 
224 

Salivary  gland,  *I5 ;  sec- 
tions of,  of  giant  crane- 
fly,  *i6;  before  and  after 
degeneration,  of  larva 
of  giant  crane-fly,  *5i 

Salix  cordata,  visited  by 
insects,  569 ;  h  u  m  i  I  i  s, 
visited  by  insects,  569 

Salvia-flower,  *572 

Salvia  oMcinalis,  speciali- 
zation of,  for  insect  pol- 
lination, 573 

Sajiiia  ceanothi,  419;  ce- 
cropia,  418,  *4i9;  larva 
of,  *420 ;  moth  and  co- 
coon cut  open  to  show 
pupa  of,  *367 ;  Columbia, 
419;  glovcri,  419 

San  Jose  scale,  *i8i,  *i82, 
*i84 

Sand-cricket,  *I56,  157 

Sand-diggers,  thread- 
waisted,  493 

Sanninoidca  cxitiosa,  389; 
larva  of,  *39i ;  cocoons 
and  empty  pupal  skins 
of,  *39i ;  moths  of,  *39o; 
eggs  of,  *390;  pacifica, 
389 

Sapcrda  Candida,  *28s 

Sarcophaga     sarracenicE, 

343.  *344 
Sarcophaginse,    341,    343 


Sarcopsylla  penetrans,  355 

Sarcopsyllidse,  Sarcopsyl- 
la ((^op^,  sarx,  flesh ; 
ipvMa,  psylla,  a  flea), 
355 

Sargus,  330 

Saturnia,  370 

Saturniina,  Saturnia  {Sat- 
urn), 417 

Satyrs,  457 

Saw-fly,  *464 ;  develop- 
ment of  egg  of,  *69 ; 
ocellar  lens  of  larva  of, 
*30 

Saw-flies,  463,  464 

Saw-horned  fish-fly  laying 
eggs,  *225 

Scale  of  Hcpialus  mcgla- 
shani,  *589 

Scale  of  Lycomorpha  con- 
st ans,  *592 

Scale-insects,  180 

Scales,  arrangement  of,  on 
wing  of  butterfly,  *59i ; 
base  of,  *59i  ;  develop- 
ment of,  on  wing  of 
Anosia  plcxippus,  *595; 
development  of,  on  wing 
of  Euvancssa  antiopa, 
*594  :  single,  from  moths 
and  butterflies,  *589 ; 
from  wing  of  Glovcria 
arizoncnsis,  *593 ;  from 
wing  of  goat-moth, 
*594;  from  wing  of 
H  e  li  c  o  nia  sp.,  *594 ; 
from  wing  of  Mega- 
lopygc  crispata,  *593; 
of  moths  and  butterflies, 
producing  color,  594 ;  of 
moths  and  butterflies, 
structure  and  arrange- 
ment, 589;  of  springtail, 
*64 ;  on  wing  of  mon- 
arch butterfly,  *36o ;  on 
.  wings  of  Culcx  fatigans, 
*3io 

Scallop  -  shell       geometer, 

*399 
Scapteriscus        didactylus, 

*i6i 
Scarabeid  beetle,  larva  of, 

*274 ;  leaf-chafers,  275 
Scarabseidse,        Scarabseus 

(scarabccus,     a     beetle), 

272,  273 
Scatophaga  sp.,  *348 
Scavenger-beetle,  272,  273 


670 


Index 


Scepsis  fulvicollis,  411 

Sciara,  325 

Schistoccrca  americana, 
*I39,  141 ;  cinarginata, 
*I40 

Schizura,  395 

Sclerite,  *5 

Scolytidje,  S  c  o  1  y  t  u  s 
{aKo/.vTTTEiv,  scolypten, 
to  strip  [bark]),  294,  297 

Scorpion-flies,  55,  223,  236 

Screw-worm  fly,  344 

Scuddcria  furcata,  *I52; 
pistillata,  *I52 

Scutelleridse,  Scutellera 
(scutuin,  a  small  shield), 
195,  207 

Scutellum  (dorsal  trian- 
gular piece  at  the  base 
of  and  between  elytra  or 
fore  zvings) 

Scydmsenidse,  Scydmsenus 
(i7Kvd/Liaivo^,  scydmccnns, 
angry-looking,  sad-col- 
ored), 265 

Seed-gall,  jumping,  472 

Segment,  5 

Self-pollination,  564 

Scnilia  caniclis,  *i6g 

Sense  of  hearing,  29;  of 
sight,  30 ;  of  smell,  27 ; 
of  taste,  26;  organs,  24; 
tactile,  26 

Senses,  special,  24 

Scpedon   fascipcnnis,   *350 

Sericostomatidse,  Sericos- 
toma  {(^vP'-'^og,  sericus, 
silken ;  orSfia,  stoma, 
mouth),  244,  245 

Sermyle,  133 

Serosa,  38 

Serphiis  dilatus,  200;   sp., 

*200 

Serrate,  *250 

Serricornia  (serra,  a  saw ; 
cornii,  horn),  251,  265; 
key  to  families  of,  265 

Sesia  pictipes,  *392 ; 
tipuliformis,   390 

Sesiidse,  Sesia  ((^vc,  ses,  a 
moth),  368,  388 

Setting-board  with  butter- 
flies properly  spread, 
*638 ;  cross-section  of, 
showing  construction, 
*638 ;  how  to  make,  638 

Seventeen-year  Cicada, 
166,  167 


Shad-flies,  65 

Sheep-louse,  *2I9 

Sheep-tick,    351,    *3S2 

Shield-backed  bugs,  195, 
214;  grasshopper,  *I55 

Shore-bug,   195,  *202 

Short  -  beaked  mosquito, 
*309 ;  pupa  and  larva  of, 
*309 

Short-winged  cricket,  *I58 

Short-winged  locust,  *I40, 
*I4I,    142 

Sialidse,  Sialis  (oialig,  si- 
alis  a  kind  of  bird), 
key  to  genera  of,  224; 
key  to  larvae  of,  224 

Sialis,  224;  infumata,  ma- 
ture stages  of,  *225 

Sibinc   stiniulea,    384 

Sight,  sense  of,  30 

Silkworm  dissected,  *43o; 
mulberry,  ^428,  *429 

Silkworm-moths,  369 

S  i  I  p  h  a  americana,  261 ; 
lapponica,  261  ;  novebo- 
racensis,   *26i,   262 

Silphidas,  Silpha  {ailtprj, 
silphe,  a  beetle), 258,  261 

S  i  I  V  an  u  s  surinamensis, 
stages  of,  ^262 

Silver-spots,   456 

Silver-spotted  skipper,  442 

Silviiis  pollinosus,  329 

Simplecta  sp.,  venation  of 
wings  of,  *32i , 

Simuliidse,  S  i  m  u  1  i  u  m 
{simulare,  imitate),  304, 
,313  . 

Simulium  sp.,  *3i2;  head 
of  larva  of,  showing  de- 
veloping mouth  -  parts, 
*3i4;  larva  and  pupse  of, 
*3I2;  mouth-parts  of, 
*3i3  ;  mouth  -  parts  of 
larva  of,  *3i3 ;  venation 
of  wing  of,  *3i2 

Sinoxylon  basilare,  272 

Siphonaptera  (ol^uv,  si- 
phon, tube;  awrepog,  ap- 
terus,  wingless),  56,  353; 
key  to  families  of.  355 

Siricicoidea  (see  Siri- 
cidse),  464 

Siricidae,  Sirex  (aeipr/v,  si- 
ren,  a  siren,  wasp),  463, 
466 

Sisyra  umbrata,  stages  of, 

*229 


Sitaris  humeralis,  life-his- 
tory  of,   291 

Sitrodrepa  panicea,  271 

Siiim  cicutcefoliutn,  visited 
by  insects,  571 

Skipper-butterflies,  442 

Slave  ants,  547 

Slave-maker  ants,  547 ; 
shining,  547 

Slaves,  547 

Slug,  pear-tree,  466;  rose, 
466 

Smell,  sense  of,  27 

Smelling-pits  on  antenna 
of  carrion-beetle,  *27 

Sinerinthus  geniinatus, 
*435,  437 ;  larva  of,  *436 

Smoky-moths,  369,  386 

Smynthuridae,  Sminthurus 
{afiiv&og,  s  m  i  n  t  li  u  s, 
mouse;  ovpa,  ura,  tail), 
63 

Smynthurus  aquations , 
*58;  hortensis,  63 

Snake-doctor,  76 

Snake-feeder,  76 

Snap-dragon,  specialization 
of,  for  insect  pollination, 
572 ;  visited  by  honey- 
bees, *563 

Snapping  apparatus  of 
click-beetle,  *267 

Snipe-flies,  327,  330,  332 

Snout-beetles,  294 

Snow-flea,  *64 

Snow-white   Eugonia,   398 

Snowy  tree-cricket,  *I59, 
160 

Social  wasp,  Hymenoptera 
parasites  of,  *48o 

Soldier-beetle,  269 

Soldier-bug,  banded,   204 

Soldier-flies,  327,  329 

Solenopsis  molesta,  544 

Solidago  canadensis,  vis- 
ited by  insects,  571 

Song  of  snowy  tree- 
cricket,  160 

Sooty-wings,  442 

Sound-making  lay  Orthop- 
tera,  123,  134,  150,  *ISI, 
152,  155,  *I57,  159;  file 
of  cricket,  *I57;  organ 
of  the  Cicadidae,  *i67 

Southern  grain  -plant- 
louse,   *I72 

Span-worms,  395 

Species,  56 


Index 


671 


Spermatheca,  14 

Spermatozoa  {see  Repro- 
ductive organs) 

Spcycria  idalia,  456 

Sphccrophthalma  aureola, 
498;  califoriiica,  498;  pa- 
cifica,     *498 ;     similima, 

*497 

Spharagemon  bolli,  *I46; 
coll  arc,   *I46 

Sphccina  ((T0r;^,  sphex,  a 
wasp),  463 

Sphcciiis  spcciosiis,  500 

Sphecoidea  (sec  Sphc- 
cina), 464 

Sphenophorus,  297 

Sphex  ichneumonea,  499; 
occitanica,  *492 

S plungicampa  hicolor,  429 

Sphingidse,  Sphinx  ((y<ihi, 
sphigx,      sphinx),      369, 

431 

Sphinx,  437  ;  chersis,  larva 
of,  showing  threatening 
attitude,  *6o6 ;  gordiiis, 
*436 

Sphinx-moth,  431 ;  front 
of  head  of,  showing 
frontal  sclerites  and 
mouth-parts  o  f  ,  *362 ; 
mouth-parts  of,  *io; 
pen-marked,  larva  of, 
showing  threatening  as- 
pect. *6o6 ;  sucking  pro- 
boscis of,  *36o 

Sphyraccphala  brevicor- 
nis,  347 

Spice  -bush  swallowtail, 
450 

Spilosoma  virginica,  412 

Spiracles,  7,  19 

Spittle-insects,  170;  stages 
of  froth  production,  *I7I 

Spondylidse,  S  p  o  n  d  y  1  i  s 
(aTT6v6v?iog,  spondylus, 
a  vertebra,  a  joint),  277, 
285 

Sporotrichum  globulife- 
rum,  212;  sp.,  *346 

Spotted-winged  locust, 
*i4i 

Spotted  wingless  grass- 
hopper, *iS4 

Spreading-boards,  how  to 
make,  638 

Spring  azure,  443 

Spring  canker-worm,  397 


Springtail,   American,   64; 

pond-surface,  *58 ;  scales 

of,  *64;  spotted,  *63 
Sprinkled  locust,  *I40,  142 
Spur,  232 
Squash-bug,  *2i3 ;  family, 

195 
Squash-vine  borer,  391 
Stable-fly,  *342 
Stag-beetle,  272,  *273 
Staphylinidse,    Staphylinus 

((jra^vAiTOf,    staphylinus, 

a  kind  of  insect),  258,  260 
Staphylinus      cinnamoptc- 

rus.  261 ;  maculosus,  261 ; 

toincntosus,   261 ;    viola- 

ceus,  261 
Stegomyia,   305,   307 ;   fas- 

ciata,  308 
Stelidse,    S  t  e  1  i  s    {oteIl^, 

stelis,  a  parasitical 

bee),  515 
Stcnobothrus     curtipcnnis, 

*I40,  142 
Stenopehiiatus     sp.,     *I56, 

Stcnopogon    inquinatus, 

Stcphania  picta,  *I97 
Stephanidse,      Stephanus 

(aTEipavog,     stephanus, 

crown),   463 
Sternum    (ventral  wall  of 

a   body  segment) 
Sthcnopis    argenteo-macu- 

latus,  373 
Stigma     (opaque    spot, 

costal  area  of  wing) 
Stigmata,  19 
Stilt-bugs,  195,  214 
Sting    of    the    honey-bee, 

460,  *46i 
Stink-bugs,   195,  214.  *2is 
Stobera  tricarinata,  *i68 
Stomoxys  calcitrans,  *342 
Stone-crickets,  155 
Stone-flies,  53,  65,  70;  life- 
history  of,   71 
Stone-fly,    *72 ;    exuvia   of 

nymph    of,    *7i ;    young 

(nymph)  of,  *7i 
Stratiomyia,  330 
Stratiomyidse,   Stratiomyia 

(arpaTtuTTjc,      stratiotes, 

a   soldier;  iivia,   myia,  a 

fly)-  327,  329 

Strawberry       root  -  borer, 
*374 


Strepsiptera      (aTpf:<pEiVj 

strephen,    twist ;    nrepov, 

pterum,  wing),  293 
Striped  ground-cricket, 

*I59 
Stylopidse,  Stylops  (  arv^iog, 

stylus,  a  pillar ;   uip,  ops, 

eye,  face),  293,  294 
Stylops,  294 

Subcosta    (see   Venation) 
Sugar-beet  midge,  345 
Sugar-maple  borer,  *283 
Sulphur  -  colored     tortrix, 

*38o 
Suture,  *5 
Swalloiv-tailed    butterAies, 

446,  *447 ;  butterfly, 

chrysalicl  of,  *448 
Swarming   of    honey-bees, 

525 
Swifts,  368,  372 
Sword-bearer,    *iS3 
Sympathetic   nervous   sys- 
tem,   23 ;    of    larva    of 

harlequin-fly,  *24 
Syinphasis  signata,  *234 
Synithnrus  aquaticus,  64 
Synchloe  sara,  446;  genu- 

tai,  446 
Synchlora  glaucaria,  398 
Synhalonia,  515 
Syntomidae  (prob.  cvvrofiia, 

syntomia,       abridgment, 

shortness),  410 
Syritta  pipicns,   340 
Syrphid,     rat-tailed    larva 

of,  *340 
Syrphidffi,  Syrphus  (  ffi'P^of, 

syrphus,    a    gnat),    332, 

339 
Syrphus,    340 ;    continuax, 
venation     of     wing     of, 

*339 

Syrphus-flies,  339 

Syssphinx  heiligbrodti,  429 

Tabanidse,  Tabanus  (ta- 
baniis,  a  horse-fly),  327, 
328 

Tabanus,  329 ;  lineola,  *328 

Tachina-fly,  345,  *346 

Tachinid  parasite  of  Cali- 
fornia flower-beetle,  *346 

Tachininse,  341,  345 

Tactile  hair,  innervation 
of,  *26 ;  sense,  26 

Tsenidia.    *ig 

Tasniopteryx,   7:^ 

Tapestry-moth,    374 


672 


Index 


Tarantula-killer,  *500,  SOI 

Tarsi,  *6;  of  beetles,  *250 

Taste,  sense  of,  26 

Tegmina,  134 

Tegulse  (cup-like  scale 
over  base  of  forewing), 
490 

T  e  I  e  a  polyphemus,  420, 
*42i ;  larva  of,  *42i 

Telephorus  bilineatiis,  270 

Tcnebrio  molitor,  289 ;  ob- 
scurus,  289 

Tenebrionidse,  Tenebrio 
(tenebrce,  darkness), 
288 

Tent  -  caterpillar,  apple- 
tree,  415 ;  forest,  415 

Tent-caterpillar  moths, 
370 

Tenthredinidas,  Tenthredo 
(TEvOprjSuv,  tcnthredon, 
a  kind  of  wasp),  463, 
464 

Tenthredinidoidea,  (see 
Tenthredinidae),   464 

Tcrias  nicippe,  446 

Termes,  102 ;  bcllicosus, 
106 ;  depredation  b  y  , 
107 ;  Aavipes,  comple- 
mentary queen,  *I03; 
habits  of,  102,  103 ; 
winged  male,  *I03; 
worker,  *I02 ;  lucifugus, 
104;  redmani,  *io6 

Termites,  55,  99;  artificial 
distribution  of,  108; 
food  of,  loi,  109;  forms 
in  a  community,  loi ; 
key  to  genera  of,  102 ; 
of  Africa,  106 ;  origin  of 
castes  of,  108 ;  nests  of, 
*ioo ;  sheds  in  Samoa, 
*ioi ;  structure  of,  loi 

Termitogaster  texana,  a 
rove-beetle,  *552 

Termitophiles,  108 

Termitophily,   108 

Termopsis,  102 ;  angusti- 
collis,  99,  *I04;  habits 
of,  104,  105,  106 

Terrifying  appearances, 
604 

Tetanocera  pictipes,  *348 

Tetracha,  253 

Tetragoneuria  epinosa,  *96 

Tetramera  {rerpa,  tetra, 
four ;  fiepoq,  m  e  r  us  , 
part),  252,   277 


Tetraopes  tetraophthalmus, 
284 

Tettigidea  lateralis,  *I48, 
149 

Tettiginae,  136,  147 

Tettix  granulatus,  *I48 ; 
0  mat  us,  *i48 

Thalessa  lunator,  *484 

Tliecla  halesus,  444 

Therioplectes,  329;  sp., 
mouth-parts  of,  *329 

Thinopinus  pictus,  261 

Thistle-butterfly,  454 

Thorax,  parts  of,  *6;  sec- 
tion of,  showing  attach- 
ment of  leg  and  wing 
muscles,  *5 

Thread-legged  bugs,  195, 
204,    *205 

Thrips,  55,  *2i9;  alimen- 
tary canal  of,  *I5 ;  head 
and  mouth-parts  of,  *8 ; 
mouth-parts  of,  *220 ; 
respiratory  system  of, 
*i8 ;  tabaci,  221 

Thyreus  abbotti,  437;  lar- 
va of,  *437 

Thyridoptcryx  ephemcrce- 
formis,  386,  *387 ;  vena- 
tion of  wing  of,  *389 

Thysanoptera  (dvaavog, 
thysanus,  a  tassel ;  TVTEp6v, 
pterum,  a  wing),  55,  220 

Thysanura  (0v(javoc,  thy- 
sanus, tassel ;  ovpa,  ura, 
tail),  60;  key  to  families 
of,  60 

Tibia,  *3,  *6 

Tide-rock  fly,  *3II 

Tiger-beetles,  252 

Tiger-moths,  370,  411 

Tiger  swallowtail,  449 

Tinea  biselliella,  374;  pel- 
lion  ella  ,  *2>73,  374 ; 
tapetzella,  374 

Tineidse      (see     Tineina), 

374 
Tineina  {tinea,  a  gnawing 

worm),  133,  368,  374 
Tingitidai,   Tingis    (Fabri- 
cius,     1803, — etym.     un- 
certain),  195,  207 
Tiphia  inornata,  497 
Tipulidse,    Tipula    (tipula, 
a  water  spider),  304,  321 
Tmetocera  ocellana,  *38i 
Toad-bug,  194,  *202 
Tobacco-worm  moth,  434 


Tolype  velleda,  416 
Tomato-worm  moth,  434 
Tomicus       plastograplius, 

galleries  and   stages   of, 

*299 
Tomognathus   americanus, 

547 ;  sublocvis,  male  and 

ergatoid  female,  *535 
Tortoise-beetle,  *28o,  281 
Tortricina,   Tortrix    (fem. 

of     tortor,     tormentor), 

368,  374,  379 
Tortricid,    venation    of    a, 

*38o 
Toxoptera  gramineum,  va- 
rious stages  of,  *i72 
Tracheae,  7,  10 ;  in  head  of 

cockroach,     *I9;     struc- 
ture of,  *20 
Tracheal    gi  11  s  ,    20 ;    of 

May-fly  nymph,  *20 
Tracheal  system  of  beetle, 

*i8 
Traniea  lacerata,  95 
Tree-bug,    bound,    214 ; 

green,  214;  spined,  *2i5 
Tree-hoppers,   168 
Tremex  c'olumba,  ^467 
Tremex,  pigeon,  *467 
Tricenodes  ignita,  *243 
Trichodectes    latus,    *I20, 

121  ;  parumpilosus,  *I20, 

121 ;  pilosus,  121 ;  scala- 

ris,     *I20,     121 ;    subro- 

stratus,  121 
Trichodectidse,  T  r  i  c  h  o  - 

dectes  (9p'?,    thrix,  hair  ; 

SijKTTjc,    dectes,  bite),  it8 
Trichodes,     270 ;     apianis, 

270;  ornatus,  *269 
Trichoptera     ( 5p''s,     thrix, 

hair;     Trrepov,    pterum, 

wing),  55,  223.  239;  key 

to    families    of,    244 
Tridactylus  apicalis,  *i6i 
Trigonalidse,       Trigonalys 

(  rpiyuvoc,     t  r  i  g  0  n  u  s  , 

three-  cornered ;  u?mc, 

alas,  disk),  463 
Trimera  (I'P"?,   tris,  three; 

fiepoq,     merus,    a    part), 

252,  286 
Trimerotropis       maritima, 

*I47 
Trimerotropis,     protective 

resemblance  of,  147 
Trinoton,      119;     luridum, 

116,  120 


Index 


673 


Triphleps  insidiosus,  206 

Tripoxylon  alboptlosum, 
502 ;  frigidum,  502 ;  ru- 
brocinctum,  502 

Triprocris,  388 

Triungulin,  290 

Trochanter,    *247 

TrocJiilium  fraxini,  *392 

Tropizaspis  sp.,   *I55,    156 

Tropcca  luna,  420,  *422; 
cocoons  of,  *423 

Trox,  275 

Trumpet-galls  on  leaves  of 
California  white  oak, 
*470 

Trypeta  longipennis,  *349 ; 
ludens,  350;  solidaginis, 
350 

Trypetidae,  Trypeta 
( Tphiravov,  trypanum,  a 
borer),  350 

Tryxalinse,  136,  142 

Tumble-bugs,  273,  274 

Turkey-gnats,  313 

Turnus  butterfly,  449 

Tussock-moth,  degenerat- 
ing muscle  of,  *50 ;  de- 
veloping mouth-parts  of, 
*363 ;  larva  of,  *405  ; 
parallel-lined,  405 

Tussock-moths,  370,  404 

Twig-insect,  *6o3 

Two-striped  locust,  *I38, 
141 

Typhlocyba  rosa,   170 

Udcopsylla  robusta,  *154 
Uloma  impressa,  289 
Ulula  hyaiina,  *232 
Underground   nest   of  the 
California      honey  -  ant, 

*S4 
Underwings,    a    group    of 

red  and  yellow,  *400 
Utetheisa  bella,  413 

Valves  of  dorsal  vessel  or 

heart,  *i8 
Vanessa      atalanta,      454 ; 

cardui,  454 ;  caryos,  454 ; 

huntera,  454 
Vedalia     cardinalis,      186, 
-    *i87,  287  _ 
Veins  of  wings,  10 
Veliidae,     Velia     (perhaps 

Velia,  a  Greek  colony  in 

Southern     Italy),      195, 


Velvet-ants,  497 

Venation,  10;  of  a  cossid, 
*38s  ;  of  dragon-fly  wing, 
*89;  of  a  Geometrid, 
*396;  of  monarch  but- 
terfly, *ii;  of  social 
wing,  *ii3;  of  a  Pyro- 
morphid,  *389;  of  a 
Tortricid,  *38o ;  wing 
o  f  Anthrax  fulviana, 
*2,i3\  of  wing  of  bag- 
worm  moth,  *389;  of 
wing  of  Bibio  albipennis, 
*326 ;  of  wing  of  black- 
fly,  *3i2;  of  wing  of 
Chrysophila  thoracia, 
*330 ;  of  wing  of  crane- 
fly,  *32i  ;  of  wing  of 
dance-fly,  *335 ;  of  wing 
of  Dixa  sp.,  *32o;  of 
wing  of  a  Dolichopodid, 
*336 ;  of  wing  of  fungus- 
gnat,  *32S ;  of  wing  of 
Hepialus  gracilis,  *372 ; 
of  wing  of  horse-fly, 
*328 ;  of  wing  of  Lucilia 
ccesar,  *344 ;  of  wing  of 
Microptcryx  sp.,  *372; 
of  wing  of  monarch 
butterfly,  *37i ;  of  wing 
of  net-winged  midge, 
*3i7;  of  wing  of  Odon- 
tomyia,  *329 ;  of  wing  of 
Pyralid  moth,  *376 ;  of 
wing  of  robber-fly,  *33i ; 
of  wing  of  Syrphus  con- 
tinuax,  *339 

Ventral  (bellyward) 

Ventral  plate,  38 

Vertex,  142 

Vespa,  503,  506;  crabro, 
nest  of,  *S04 ;  cuncata, 
506 ;  germanica,  506 ; 
maciilata,  506;  sp.,  *505 

Vespidse,  Vespa  {vespa,  a 
wasp),  key  to  genera  of, 
S03 

Vespina  (see  Vespidae), 
463 

Vespoidea  (see  Vespidae), 
464 

Viceroy,  452 ;  butterfly 
mimicking  monarch  but- 
terfly, *6io 

Vine-hoppers,    *I70 

Vine-loving  pomace-fly,  349 

Violet-tip  butterfly,  454, 
*455  ' 


Vitelline  membrane,  27 
Volucella,  340 

Walking-stick,  *I3I,  132, 
*6o3 

Walking-sticks,  126;  key 
to  genera  of,  132 

Walnut-moth,  regal,  246, 
*427 ;  larva  of,  *427 

Warble-flies,  338 

Warning  colors,  604 

Wasp,  development  of 
mouth-parts  of,  *46o, 
461 ;  mouth-parts  o  f  , 
*46o ;  mouth-parts  of 
larva,  *46i ;  mud-dauber, 
nest  of,  *499 

Wasp-flies,   T,:22,  336 

Wasp-like  fly,  *336 

Wasps,  56,  490;  carpenter, 
nest-tunnels  of,  *502; 
classification  of,  490; 
mason,  498 ;  mimicry  of, 
by  moths,  *6o8;  nest- 
building  by,  508 ;  potter, 
498;  social,  503;  social, 
key  to  genera  of,  503 ; 
solitary,  491 ;  classified 
by  habits,  497 ;  habits  of, 
492;  stinging  prey,  495; 
structure  of,  491 ;  true, 
463 

Water-beetle,  stages  in 
development  of  nervous 
system  of,  *25 

Water-boatmen,  194,  198, 
*I99 

Water-bug,  giant,  199, 
*200 ;  western,  *200 

Water-creepers,   199 

Water-net,  *639 

Water  scavenger  -  beetle, 
259 ;  development  of  egg 
of,  *38;  external  anat- 
omy of,  *247 

Water-scorpion,  194,  *20i ; 
eggs  of,  *20i 

Water-skater,   ocean,   *I97 

Water-striders,  195,  196, 
*I97;  broad-bodied,  *I97 

Water-tiger,  ^256 

Wax-making  o  f  honey- 
bee, 526 

Wax   secreted   by   aphids, 

175. 
Webbing  clothes-moth,  374 
Web-worm,  fall,  412 
West-coast  lady,  454 


6/4 


Index 


Western  cricket,  *I56,  157 

Wheat-thrips.  221 

Wheel-bugs,  203 

Whirligig-beetle,  252,  *257 

Whirligigs,  255 

White  ants,  99 

White-lined  sphinx,  435 

Wing,  of  butterfly,  ar- 
rangement of  scales  on, 
*59i ;  developing,  of  cab- 
bage-butterfly, *ii;  of 
monarch  butterfly,  part 
of,  showing  scales,  *36o; 
muscles  of,  *S 

Wing-buds,  development 
of,  of  giant  crane-fly, 
*48 

Wings,  9 ;  of  butterflies, 
androconia  from,  *592 ; 
of  Heteropters,  showing 
venation,  *i96;  of  locust, 
development  of,  *42 

Winthcmia,  4-pustuluta, 
*347 

Wood-boring  beetle,  giant, 
development  of  color- 
pattern  in,  *598 

Wood-borers,  metallic, 
265 

Wood  leopard-moth,  385 


Wood-nymph,  *409,  410, 
457;  moths,  370,  407 

Woolly  apple-aphis,   179 

Woolly-bear  caterpillars, 
*4ii 

Workers,  459 


Xenos,  294;  sp.,  parasitiz- 
ing Polistes,  *29 

Xestopsylla,  355 ;  gallina- 
cea,  356 

Xiphidium,  154;  attenu- 
atiim,  *i54 

Xylina  antcnnata,  *402 ; 
grotei,  *402 ;  lacticincra, 
parasitized  larvae  of,  *486 

Xylocopas,    513 


Yellow-fever,  mosquitoes 
and,  630 

Yellow- jacket,  communal 
nest  of  the,  ^505 ;  nest 
of,  Vespa  sp.,  cut  open 
to  show  combs  within, 
*5o6 ;  queen,  nest  of, 
*507 

Yellow-jackets,  *505,  506 

Yellow-winged  locust,  *I44 


Yolk,  37 

Ypsolophus  pomatellus, 
*374;  larva  of,  ^373 

Yucca-borer,  441 

Yucca  aiamentosa,  specifi- 
cation of,  for  insect  pol- 
lination, 576 

Yucca,  pronuba  moth  rub- 
bing pollen  down  a  stig- 
matic  tube  of,  *578 ;  pro-  ■ 
nuba   moth   laying  eggs 
in  ovary-tube  of,  *577 

Zaitha  iiuminea,  *200 
Zalysus  spinosus,  214 
Zebra  swallowtail,  448 
Zcrena  ccesonia,  446 ;  eiiry- 

dice,   446 
Zeusera  pyrina,  385 
Zodion,  337 

Zygsenid,  venation  of,  *4ii 
Zygsenidse,  Zygsena  [Fabri- 
cius,  177s]  {^vyaLva,  zy- 
gasna,  supposed  to  mean 
the  hammer  -  headed 
shark),  370,  410 
Zygoptera  (prob.  ^vyov, 
zygum,  yoke;  ~Tzpnv, 
pterum,  wing),  89;  key 
to  families  of,  89 


THE  AMERICAN   NATURE   SERIES 

•  The  fortunate  increase  in  the  attention  paid  by  the  American  people 

to  Nature  study,  has  led  to  the  publication  of  many  popular  books  oti  the 
subject,  some  of  which  are  good,  and  some  not.  In  the  hope  of  tloing 
something  toward  furnishing  a  series  where  the  seeker  will  surely  find  a 
readable  book  of  high  authority,  the  publishers  of  the  American  Science 
Series  have  begun  the  publication  of  the  American  Nature  Series.  It  is 
the  intention  that  in  its  own  way,  the  new  series  shall  stand  on  a  par  with 
its  famous  predecessor. 

The   primarj'    object   of  the  new  series  is  to  answer  questions — -those 

(outside  of  the  domain  of  philosophy)  which  the  contemijlation  of  Nature 

is  constantly  arousing  in  the  mind   of  the    unscientific    intelligent   person. 

But    a  collateral  object   will   be    to  give    some  intelligent    notion    of  the 

causes  of  things." 

The  books  will  be  under  the  guarantee  of  American  experts,  and 
from  the  American  point  of  view ;  and  where  material  crowds  space,  pref- 
erence will  be  given  to  American  facts  over  others  of  not  more  than  equal 
interest. 

The  series  will  be  in  five  divisions : 

GROUP  I.     CLASSIFICATION  OF  NATURE 

This  division  will  consist  of  three  sections. 

Section  A.     A  large  popular  Natural  History  in  several  volumes, 

with  the  topics  treated  in  due  proportion,  by  authors  of  unquestioned 
authority.  There  is  no  existing  Natural  History  which  does  not  fall  short 
in  some  one  of  these  particulars.  Possibly  the  Natural  History  in  the 
American  Nature  Series  may  not  be  kept  ideal  regarding  all  of  them,  but 
if  it  is  not,  the  fault  will  not  be  due  to  carelessness  or  apathy  on  the  part 
of  the  publishers. 

The  books  so  far  arranged  for  in  this  section  are : 

FISHES,  by  David  Starr  Jordan,  President  of  the  Leland  Stanford  Uni- 
versity.     2  Volumes. 

INSECTS,  by  Vernon  L.  Kellogg,  Professor  in  the  Leland  Stanford  Junior 
Universit}\      $5.00  net;  carriage,  35  cents. 

TREES,   b}^  N.  L.  Britton,  Director  of  the  New  York  Botanical  Garden. 

WILD  MAMMALS  OF  NORTH  AMERICA,  by  C.  Hart  Merriam,  Chief 
of  the  United  States  Biological  Survey. 

BIRDS  OF  THE  WORLD.  A  popidar  account  by  Frank  H,  Knowlton, 
M.S.,  Ph.D.,  Member  American  Ornithologists  Union,  President 
Biological  Society  of  Washington,  etc.,  etc.,  with  Chapter  on  Anatomy 
of  Birds  by  Frederick  A.  Lucas,  Chief  Curator  Brooklyn  Academy 
Arts  and  Sciences,  and  edited  by  Robert  Ridgway,  Curator  of  Birds, 
U.  S.  National  Museum. 
Section  B.     A  Shorter  Natural  History  by  the  authors  of  Section  A, 

preserving  its  popular  character,  its  proportional  treatment  and  its  author- 
ity so  far  as  that  can  be  preserved  without  its  fullness. 

Section  C.     Identification  Books— "  How  to  Know,"  brief  and  in 

portable  shape.      By  the  authors  of  the  larger  treatises. 


AMERICAN       NATURE       SERIES      {Continued) 

GROUP  II.    FUNCTIONS    OF   NATURE 

These  books  Avill  treat  of  the  relation  of  facts  to  causes  and  effects — 
of  heredity  in  oi-ganic  Nature,  and  of  the  environment  in  all  Nature.  In 
treating  of  Inorganic  Nature,  the  ph.vsical  and  chemical  relations  will  be 
specially  expounded ;  and  in  treating  of  organized  creatures,  the  relations 
to  food  and  climate,  with  the  i)eculiarities  of  their  functions — internal  and 
external. 

THE  BIRD:  ITS  FORM  AND  FUNCTION,  by  C.  W.  Bkebe,  Curator 
of  Birds  in  the  New  York  Zoological  Park.  8vo,  490  pp.  $,S.50  net; 
by  mail,  $3.80. 

GROUP  III.     REALMS  OF  NATURE 

Detailed  treatment  of  various  departments  in  a  literary  and  popular 
way. 

Already  published : 
FERNS,  by  Campbell  E.   Waters,  of  Johns   Hopkins   University.      8vo, 

pp.  xi  +  362.      Price  $3.00  net;  by  mail,  $3.30. 

GROUP  IV.     WORKING  WITH  NATURE 

How  to  ijropagate,  develop  and  care  for  the  plants  and  animals. 

Published  in  this  division  is : 
NATURE  AND  HEALTH,  by  Edward  Curtis,  Professor  Emeritus  in  the 

College  of  Physicians  and  Surgeons.    12mo,  $1.25  net;  by  mail,  $1.37, 

Arranged  for  are: 
CHEMISTRY  OF  DAILY  LIFE,    by    Henrv    P.    Talbot,    Professor   of 

Chemistry  in  the  Massachusetts  Institute  of  Technology. 

DOMESTIC  ANIMALS,  by  William  H.  Brewer,  Professor  Emeritus  in 
Yale  University. 

THE  CARE  OF  TREES  IN  LAWN,  STREET  AND  PARK,  by  B.  E. 

Fernovv,  Late  Head  of  the  Cornell  School  of  Forestry. 

GROUP  V.    DIVERSIONS  FROM  NATURE 

This  division  will  include  a  wide  range  of  writings  not  rigidly  system- 
atic or  formal,  but  wi-itten  only  by  authorities  of  standing. 

FISH  STORIES,  b}'  David  Starr  Jordan,  President  of  the  Leland  Stan- 
ford Junior  University. 

HORSE  TALK,  by  William  H.  Brewer,  Professor  Emeritus  in  Yale 
University. 

BIRD  NOTES,  by  C.  W.  Beebe,  Curator  of  Birds  in  the  New  York 
Zoological  Park. 

HENRY      HOLT      AND      COMPANY,     Publishers 

29   WEST  TWENTY-THIRD    STREET,    NEW   YORK 


The    Natural    History    of  Plants 

THEIR  FORMS,  GROWTH,  REPRODUCTION 
AND    DISTRIBUTION 

FROM  THE  GERMAN  OF 

ANTON    KERNER   von   MARILAUN 

Professor  of  Botany  in  the  University  of  Vienna 

By    F.    W.    OLIVER 

Quain   Professor  of  Botany  tit   University   College,   London 

WITH    THE   ASSISTANCE    OF 

MARIAN  BUSH  and  MARY  E.  EWART 
4to.     New  edition.     2  vols.     The  set        -        -        $11.00 

A  work  for  reference  or  continuous  reading,  at  once  popular  and,  in  the  modern  sense, 
thoroughly  scientific.  The  new  edition  is  practically  identical  with  the  former  four-volume 
edition  except  that  the  colored  plates  in  the  latter  have  been  omitted.  The  wood-engrav- 
ings, over  two  thousand  in  number,  have  been  retained. 

Prof.  John  M.  Coulter,  in  The  Dial:  "  Prof.  Kerner  has  brought  the  most  recent  re- 
searches within  reach  of  the  intelligent  reader,  and  in  a  style  so  charming  that  even  the 
professional  teacher  may  learn  a  lesson  in  the  art  of  presentation.  ...  It  is  such  books  as 
this  that  will  bring  botany  fairly  before  the  public  as  a  subject  of  absorbing  interest; 
that  will  illuminate  the  botanical  lecture-room." 

Prof.  Chas.  R.  Barnes,  in  The  Botanical  Gazette:  "  This  lucidity,  and  the  ex- 
cellent illustrations,  not  only  will  introduce  the  non-botanical  reader  to  the  science  of 
botany,  but  should  serve  as  a  lesson  to  the  professional  botanist  in  the  art  of  presenta- 
tion." 

The  Nation  :  "  He  has  succeeded  in  constructing  a  popular  work  on  the  phenomena  of 
vegetation  which  is  practically  without  any  rival." 

GUIDE    TO    THE    STUDY    OF    INSECTS 

AND   A   TREATISE   ON   THOSE 

INJURIOUS  AND   BENEFICIAL  TO  CROPS 

FOR   THE   USE    OF 

COLLEGES,    FARM-SCHOOLS  AND   AGRICULTURISTS 

By  ALPHEUS  S.   PACKARD,   M.D. 

With  685  illustrations.     Ninth  edition.     xii4-7i5  pp.,  8vo,  $5.00  net 

PLANT    PHYSIOLOGY 

By  GEORGE  J.  PEIRCE 

Professor  in  Leland  Stanford  University 

vi  +  291  pages,  Svo        _        -        -        _        $2.00 

A  modern  and  thoroughly  scientific  discussion  of  the  general  principles  of  plant  physi- 
ology, intended  for  the  student  or  general  reader  acquainted  with  the  elements  of  botany. 

Science:  "  The  volume  is  full  of  original  suggestions  and  differs  quite  markedly  from  the 
old-time  works  devoted  to  plant  physiology." 

William  F.  Ganong,  Professor  in  Smith  College  :  "I  am  much  pleased  with  the  clear- 
ness, proportion,  and  vigor  with  which  it  treats  the  subject.  It  seems  to  me  an  admirable 
exposition  of  the  principles  of  plant  physiology  as  they  are  understood  at 
the  present  day,  and  it  should  have  a  wide  use." 

Henry  Holt  and   Company 

29  West  23d  Street,  New  York 


GEOLOGY 

Vol  I.  "Geologic  Processes  and  Their  Results" 
By   Prof.   THOMAS    C.    CHAMBERLIN 

AND 

Prof.  ROLLIN    D.    SALISBURY 

Heads  of  the  Departments  of  Geology  and  Geography,  University  of  Chicago  ;  Members  of  the  United 
States  Geological  Survey;  Editors  of  the  Journal  of  Geology 

With  numerous  illustrations,  including  24  colored  maps  and 
3  tables.     654  pages,  8vo,  $4.00  net 

Vol.  IL   "Earth   History."      In  preparation 

Chas.  D.  Walcott,  Director  of  U.  S.  Geological  Survey:  "  I  am  impressed  with  the 
admirable  plan  of  the  work  and  witli  the  thorough  manner  in  which  geological  principles 
and  processes  and  their  results  have  been  presented.  The  text  is  written  in  an  entertaining 
style  and  is  supplemented  by  admirable  illustrations,  so  that  the  student  cannot  fail  to  obtain 
a  clear  idea  of  nature  and  the  work  of  geological  agencies,  of  the  present  status  of  the 
science,  and  of  the  spirit  which  actuates  the  working  geologist." 

T.  A.  Jaggar,  Jr.,  Harvard  University  :  "  An  excellent  statement  of  modern  Ameri- 
can geology,  with  abundant  new  illustrative  material  based  upon  the  most  recent  work  of 
government  and  other  surveys." 

Henry  S.  Williams,  Vale  University  :  '>It  is  the  best  treatise  on  this  part  of  the 
subject  which  we  have  seen  in  America." 

R.  S.  Woodward,  Columbia  University :  "It  is  admirable  for  its  science,  admirable 
for  its  literary  perfection,  and  admirable  for  its  unequalled  illustrations." 

IsRAFX  C.  Russell,  University  of  Michigan ,  "  I  deem  it  an  epoch-making  book  and 
one  that  will  vastly  extend  the  study  of  geology.' 

BUTTERFLIES 

By   S.    H.    SCUDDER 

THEIR    STRUCTURE,    CHANGES,    AND    LIFE-HISTORIES 

With  Special  Reference  to  American  Forms.     Being  an  Application  of  the  ^'^  Doctrine  of 
Descent  "  to  the  Study  of  Butterflies.      With  an  Appendix  of  Practical  Instruction 

i2mo        -        -        -        $1.50  net 


Brief  Guide  to  the  Commoner  Butterflies  of  the  Northern 
United  States  and  Canada 

Being   an   Introduction   to   the   Knowledge   of   their   Life-Histories 

New  edition.      With  2 1  plates,  containing  in  all  gy  illustrations 

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THE    LIFE    OF    A    BUTTERFLY 

A  CHAPTER  IN  NATURAL  HISTORY  FOR  THE  GENERAL  READER 
l6mo  -  -  -  $1.00 

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FERNS 


A  MANUAL   FOR  THE   NORTHEASTERN   STATES 

WITH    ANALYTICAL   KEYS   BASED   ON   THE 

STALKS  AND  ON  THE  FRUCTIFICATION 

With  over  two  hundred  illustrations  from  original  drawings  and  photographs 

By    CAMPBELL    E.    WATERS 
302  pages,  square  8vo.     Boxed,  $3.00  net;  by  mail,  $3.34 

This  book  is  thoroughly  authoritative,  and  is  written  in  popular  style. 
It  covers  all  the  ferns  in  the  region  embraced  either  in  Britton's  or  in  Gray's 
Manuals. 

"  This  book  is  likely  to  prove  the  leading  popular  work  on  ferns.  No 
finer  examples  of  fern  photography  have  ever  been  produced.  Dr. 
Waters  brings  to  his  work  fifteen  years  of  experience  in  field  and  herbarium 
study,  and  the  book  may  be  expected  to  prove  of  permanent  scientific  value, 
as  well  as  to  satisfy  a  want  which  existing  treatises  have  but  imperfectly 
filled."— T'/aw/  World. 

"  For  all  who  study  or  wish  to  study  our  native  ferns  Dr.  Waters  has 
prepared  a  book  which  is  sure  to  prove  both  helpful  and  inspiring. 
Especially  charming  and  significant  are  the  views  showing  typical  habits 
and  habitats." — The  American  Naturalist. 

"There  could  hardly  be  a  better  book  for  those  interested  in  the 
subject." — Boston  Literary  World. 

OUR    NATIVE    FERNS 

AND    THEIR    ALLIES 

WITH  SYNOPTICAL  DESCRIPTION  OF  THE  AMERICAN  PT£f<:WOPHYTA 

NORTH  OF  MEXICO 

By   LUCIEN    M.   UNDERWOOD 

Professor  in  Columbia  University 
Revised,    xii  +  156  pages,  i2mo     -        -        -    |i.po 

"The  elementary  part  is  clear  and  well  calculated  to  introduce  begin- 
ners to  the  study  of  the  plants  treated  of.  The  excellent  key  makes  the 
analysis  of  ferns  comparatively  easy.  The  writer  cordially  commends  the 
book.  It  should  be  in  the  hands  of  all  who  are  especially  interested  in  the 
vascular  cryptogams  of  the  United  States." — Bulletin  of  the  Torrey  Botan- 
ical Club,  N.  Y. 

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MUSHROOMS 

By  GEORGE  FRANCIS  ATKINSON 

Professor  of  Botany  in   Cornell  University,   and  Botanist  of  the  Cornell  University 

Experiment  Station 

Recipes  for  Cooking  Mushrooms.     By  Mrs.  SARAH  TYSON  RORER 
Chemistry  and  Toxicology  of  Mushrooms.     By  J.  F,  CLARK 

With  2  JO  illustrations  from  photographs,  including  i^  colored  plates 

320  pages,  8vo.    $3.00  net ;  by  mail,  $3.23 

Educational  Review: — "It  would  be  difficult  to  conceive  of  a  more  attrac- 
tive and  useful  book.  ...  In  addition  to  its  general  attractiveness  and  the 
beauty  of  its  illustrations,  it  is  written  in  a  style  well  calculated  to  win  the 
merest  tyro." 

Moulds,    Mildews,    and  Mushrooms 

By  LUCIEN  M.  UNDERWOOD 

Professor  in  Cohi?nbia  University 

iv+236  pages,  12mo        -        -        .        -        $1.50 

Bradley  M.  Davis,  in  the  Botanical  Gazette: — "Wonderfully  free 
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combined  with  interesting  accounts  of  life-habits  and  activities-.  ...  A 
marvel  in  its  compactness,  with  a  wonderfully  uniform  tone  throughout, 
condensed  and  yet  very  clear." 

Flora  of  the  Northern  States  and  Canada 

By    Professor   N.    L.    BRITTON 

Director  of  the  New  York  Botanical  Garden 

x+1080  pages,  large  12mo       -       -       -       $2.25 

This  manual  is  published  in  response  to  a  demand  for  a  handbook  suit- 
able for  ordinary  school  use,  which  shall  meet  modern  requirements  and 
outline  modern  conceptions  of  the  science.  It  is  based  on  An  Illustrated 
Flora  prepared  by  Professor  Britton  in  co-operation  with  Judge  Addison 
Brown,  in  three  volumes.  The  text  has  been  revised  and  brought  up  to 
date,  and  much  of  novelty  has  been  added,  but  all  illustrations  are  omitted. 

Conway  MacMillan,  Professor  in  the  University  of  Minnesota,  in  Science  : — 
"There  is  no  work  extant  in  tlie  whole  series  of  American  botanical  publications  which 
deals  with  descriptions  of  the  flowering  plants  that  can  for  a  moment  be  compared  with 
it,  either  for  a  skillful  and  delightful  presentation  of  the  subject-matter  or  for  modern, 
scientific,  and  accurate  mastery  of  the  thousandfold  mass  of  detail  of  which  sucli  a  work 
must  consist." 

V.  M.  Spalding,  Professor  itt  the  University  of  Michigan : — "  1  regard  the  book  as 
one  that  we  cannot  do  without  and  one  that  will  henceforth  take  its  place 
as  a  necessary  means  of  determination  of  the  plant  species  within  its  range. 

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